Delivering a set of veneers can be a stressful procedure in a dental office. Patients invest a significant amount of both time and financial resources to enhance their smiles and have worn their temporary veneers for several weeks. As they eagerly anticipate the delivery of their permanent veneers, it becomes imperative to execute a technique that guarantees the thorough removal of the flowable composite used to bond the temporary veneers. This article introduces an effective method that ensures the elimination of all remnants of flowable composite prior to the try-in and cementation of the permanent veneers. By use of this method, it serves to benefit the practitioner in 3 crucial ways. Primarily, it allows the practitioner to selectively eliminate residual flowable composite without causing damage to the prepared tooth structure. This meticulous approach significantly minimizes the risk of inadvertent tooth structure removal, particularly at the margins, thereby mitigating the potential for open margins that could undermine the overall integrity of the restoration. Moreover, this technique’s application helps to ensure the removal of all remnants of flowable composite, which, if left by mistake, could exhibit sharp edges or angles that could lead to fracture of the veneers when trying them in. And lastly, this technique helps the practitioner rule out one of the factors that could be causing the veneers not to seat completely during the try-in step of the delivery procedure. The use of “The Scorpion Technique” leads to a more predictable and systematic way to deliver permanent veneers.

Delivery of Temporary Veneers

The author has found using “the spot-etch-and-bond technique” for bonding in temporary veneers to be the most predictable method. This technique involves etching (38% phosphoric acid) a small, 2-mm circular area in the center of the prepared tooth, followed by placing Gluma (Kulzer) and then applying Scotchbond Universal Plus Adhesive (3M) on the same circular area (Figure 1). The Scotchbond Universal Plus Adhesive is light-cured for 20 seconds. A flowable composite is then applied to the intaglio surface of the temporary veneers and placed on the prepared tooth structure. All excess flowable composite needs to be removed at the margins of the temporary veneers. A rubber tip GUM Stimulator (Sunstar Americas) works well to remove any excess flowable composite without causing any trauma to the gingiva. Once all excess flowable composite has been removed, the temporary veneers are light-cured for 10 seconds.

Figure 1. Etch placed on a 2-mm circular area in the center of each tooth.

The author has tried other techniques for the retention of temporary veneers. Temporary cements such as Temp-Bond Clear (Kerr) have been used. Still, the author found the retention to be insufficient when the patients had to wear the temporary veneers for any extended time period, such as 3 to 4 weeks. It can cause frustration for both the practitioner and patient when the temporary veneers debond prior to the delivery date. Another technique that the author has tried is the “shrink-wrap technique.”¹ This technique involves using a silicone matrix filled with bisacryl material, which is seated onto the prepared teeth. The bisacryl material is allowed to completely polymerize before the silicone matrix is removed, and then the margins are refined using an extra-fine mosquito diamond bur. The author found this technique to be too retentive, and removal was time-consuming, especially if the interproximal contacts were open. There was also a concern about causing the papilla to become blunted if the linguogingival embrasures were not opened up enough during the refinement of the margins of the temporary veneers. 

The Scorpion Technique

The spot-etch-and-bond technique provides the ideal amount of retention while also allowing for adjustment of the temporary veneers. The temporary veneers can be refined in the linguogingival embrasures prior to bonding, therefore decreasing the chance of blunting the papilla, but this technique is not perfect. With the spot-etch-and-bond technique, there is still the question of whether all of the flowable composite has been removed prior to trying in the permanent veneers.

Due to the nature of both temporary and permanent veneers being very thin, the shade of the flowable composite needs to be very close to that of the stumpf shade of the tooth. A noticeable disparity in color, whether darker or lighter, will manifest through the temporary veneer, undermining the desired aesthetics. At the same time, if one selects a shade of composite that is very close to that of the stumpf shade of the tooth, then this creates a challenge in discerning and eliminating residual composite. Failure to remove all remnants of flowable composite can precipitate 2 significant issues. Primarily, any residual flowable composite poses a risk of fracturing the delicate veneer during the try-in phase of the delivery appointment. Secondly, incomplete removal of the residual composite may prevent full seating of the veneer during insertion, prompting the practitioner to question the cause.

The practitioner needs to determine whether the culprit is lingering composite or interproximal contact concerns. The Scorpion Technique emerges as an answer, facilitating a comprehensive and meticulous approach to veneer placement. This technique ensures the elimination of any lingering flowable composite and refining the overall veneer delivery process.

The author uses what she calls “The Scorpion Technique” to bond in the temporary veneers and later remove them at the delivery appointment. The protocol for this technique involves spot-etching a small, 2-mm circular area on the prepared tooth, followed by using a desensitizer, such as Gluma, and a bonding agent, such as Scotchbond Universal Plus Adhesive, which is applied on this same small, 2-mm circular area. The Scotchbond Universal Plus Adhesive is light-cured for 20 seconds. Following the light-curing of the Scotchbond Universal Plus Adhesive, OMNICHROMA FLOW BULK (Tokuyama Dental) is placed on the intaglio surface of the temporary veneers and used as the bonding agent for the temporary veneers (Figures 2 and 3). It is crucial that the excess flowable composite at the margins of the temporary veneers be removed prior to light curing for 10 seconds.

Figure 2. A 2-mm circular area of OMNICHROMA FLOW BULK (Tokuyama Dental).

Figure 3. OMNICHROMA FLOW BULK.

This technique helps ensure that the temporary veneers will remain bonded for the time required for the patient to evaluate the aesthetics, along with testing phonetics, function, and occlusion. The margins of the temporary veneers are sealed, which helps to maintain the gingival health, which is paramount when delivering the permanent veneers. During the removal of the temporary veneers, the author prepares a thin vertical line through the facial of the temporary veneer and takes care not to touch the tooth structure with the bur. A crown splitter is then used to create a torquing force between the 2 pieces of the temporary veneer, which causes the temporary veneer to debond from the tooth. 

The process is repeated until all the temporary veneers have been removed. After this process has been completed, residual flowable composite remains on the 2-mm circular area in the middle of the tooth that  was spot-etched and bonded to during the delivery of the temporary veneers. This flowable composite is very difficult to see and detect.

The author lives in Arizona where scorpions are “invisible enemies” that blend in with almost any type of flooring. The sting of a scorpion is extremely painful and can cause numbness for several hours. The scorpions have what is called a “hyaline layer” in their exoskeleton that causes them to illuminate in the dark when a black light is shone on them. The author knows that some dental composites have glass fillers that impart a fluorescent property to them.² Incorporating these artificial materials makes the composite appear more natural and lifelike. With some experimentation, the author was able to determine which flowable composites demonstrate the ability to illuminate when exposed to black light in a darker environment. After removing the temporary veneers, the overhead light is focused toward the patient’s feet to create a darker environment. If the practitioner uses loupes with a headlamp, then the headlamp needs to be turned off as well. There will still be ambient light in the room due to ceiling lighting, but no light will be directly shining on the prepared teeth. The black light is then shone on the patient’s teeth, and any residual flowable composite becomes illuminated (Figures 4 and 5). The practitioner then notes the exact location of the residual composite and removes it with a fine, flame-shaped diamond bur. It will take several sessions of shining the black light on the tooth to detect the exact location of the residual flowable composite and then going back to remove it. This very precise technique ensures only the residual flowable composite is completely removed and that the underlying tooth structure is not overly prepared, guaranteeing the veneer’s marginal fit. The practitioner is now able to rule out the residual composite as a possible cause for the permanent veneers improperly seating.

Figure 4. Photo of flowable composite on a tooth after temporary veneers have been removed.

Figure 5. Black Light (Gearlight).

During the development of this technique, several different brands of flowable composite were tested to evaluate their levels of fluorescence (Figures 6 and 7). Fluorescence, as defined, involves the absorption of light by a substance and its emission at the same time at a longer wavelength.³ Notably, OMNICHROMA FLOW BULK exhibited the most pronounced illumination when compared to the other 5 tested flowable composites. The luminescent quality of dental composites arises from the incorporation of rare earth oxides in their glass fillers.⁴

Figure 6. Evaluation of the level of fluorescence of multiple different brands of flowable composite.

Figure 7. Chart of names of flowable composites present in Figure 6.

The degree of illumination of the composite is based on the amount of rare earth oxides incorporated into the composition of the composite. When placing a composite restoration, a practitioner would want the amount of illumination to match that of the surrounding enamel and dentin, but with the Scorpion Technique, one would want the brightest level of illumination of the composite in order to easily detect it. Incorporating the Scorpion Technique will help make a veneer delivery appointment more predictable and less stressful.

CASE REPORT

A 42-year-old female had considerable damage due to severe acid reflux during her pregnancy with twins. She also had signs of damage due to bruxism. The patient expressed a desire to repair her damaged teeth and also to increase the length and fullness of her smile (Figures 8 and 9). A comprehensive evaluation was completed for this patient, which included radiographs, full-mouth periodontal probing, temporomandibular joint evaluation, and evaluation of her current occlusal scheme.

Figure 8. Preoperative frontal view full smile (1:2), non-retracted.

Figure 9. Pre-op frontal view of upper and lower teeth (1:2), retracted

After reviewing the information gathered at the comprehensive evaluation, it was determined that the patient’s central incisors were very “boxy” and did not display the ideal width-to-length ratio.⁵ The patient was presented with 2 options to correct this issue. The first option was orthodontic treatment in which the central incisors would be intruded. The second option presented was a crown-lengthening procedure. It was also discussed with the patient that she would need to have a connective tissue graft on tooth No. 6 to address the gingival recession that was present. The patient elected to have the crown-lengthening and connective tissue graft procedures completed along with having her teeth prepared for 10 porcelain veneers.

A surgical stent was fabricated from the diagnostic wax-up to act as a guide for altering the position of the gingiva on teeth Nos. 8 and 9. The patient presented for treatment, and a gingivectomy was performed on teeth Nos. 8 and 9 using the surgical guide. Teeth Nos. 4 to 13 were prepared for porcelain veneers (Figure 10). The Scorpion Technique was used to bond the temporary veneers in place. The patient was then sent to Dr. Brent Boyse at Arizona Maxillofacial Surgeons (Mesa, Ariz). Dr. Boyse used the temporary veneers as a guide for where to remove bone on teeth Nos. 8 and 9 in order to avoid having a biologic width violation with the permanent veneers. He also used the temporary veneers as a guide for the placement of the connective tissue graft on tooth No. 6. The patient remained in temporary veneers for 6 weeks while the gingiva healed. The temporary veneers were removed 6 weeks after the crown-lengthening procedure and connective tissue graft placement so that the margins could be refined. The author wanted to be sure the prepared margins were equigingival to the altered gingival tissues following the crown-lengthening and connective tissue grafting procedures. The use of the Scorpion Technique made removal of the residual flowable composite easier. It was imperative that all of the residue composite be removed because the impressions for the final veneers were taken after refinement of the margins. The patient remained in temporary veneers for 5 more weeks while the dental laboratory was fabricating the final restorations. The spot-etch-and-bond technique allowed for adequate retention of the temporary veneers and ensuring that the margins were closed.

Figure 10. Frontal view of upper and lower teeth (1:2), retracted view of prepared teeth and gingiva.

After the clinical crown-lengthening procedure, a connective tissue graft, and being in temporary veneers for almost 3 months, the patient was ready to have the permanent veneers tried in and delivered. By using the Scorpion Technique during the delivery appointment, the author was able to eliminate one of the factors that could create a problem during the trying in and seating of the permanent veneers. Even after having this patient wear 2 different sets of temporary veneers, the author could be confident that all residual flowable composite had been removed from the prepared teeth. If there were issues with the fit of the veneers, the interproximal contacts whould have been evaluated.

Figure 11. Postoperative frontal view of the full smile (1:2), non-retracted.

Figure 12. Post-op lateral view of the full smile (1:2), non-retracted.

Figure 13. Post-op frontal view of upper and lower teeth (1:2), retracted.

Figure 14. Post-op frontal view of upper and lower teeth (1:2), retracted, all teeth restored.

Figure 15. Pre-op full-face (1:10), non-retracted view.

Figure 16. Post-op full-face (1:10), non-retracted view.

This patient was so pleased with the aesthetic result of the porcelain veneers on her maxilla that she decided to proceed with having porcelain veneers placed on her mandibular arch to complete her smile makeover (Figures 11 to 16). Doing this type of dentistry demands that the practitioner display a high level of skill along with extreme attention to the smallest details. Incorporating techniques like the Scorpion Technique allows more control of the procedure and, therefore, creates a less stressful appointment for both the practitioner and the patient.

ACKNOWLEDGMENTS

The author would like to thank technicians Nelson Rego and Juan Rego of Smile Designs by Rego (Santa Fe Springs, Calif) for their laboratory support and ceramic artistry, which were critical components in the success and outcome of this case.

REFERENCES

1. Gürel G, Morimoto S, Calamita MA, et al. Clinical performance of porcelain laminate veneers: outcomes of the aesthetic pre-evaluative temporary (APT) technique. Int J Periodontics Restorative Dent. 2012;32(6):625–35.

2. Volpato CAM, Pereira MRC, Silva FS. Fluorescence of natural teeth and restorative materials, methods for analysis and quantification: A literature review. J Esthet Restor Dent. 2018;30(5):397-407. doi:10.1111/jerd.12421

3. Mualla S. Fluorescence and dentistry. IOSR-JDMS. 2016;15(3)v9:65-75. doi:10.9790/0853-1503096575

4. Leontiev W, Magni E, Dettwiler C, et al. Accuracy of the fluorescence-aided identification technique (FIT) for detecting tooth-colored restorations utilizing different fluorescence-inducing devices: an ex vivo comparative study. Clin Oral Investig. 2021;25(9):5189–96. doi:10.1007/s00784-021-03826-7

5. American Academy of Cosmetic Dentistry. AACD Guide to Accreditation Criteria: Contemporary concepts in smile design. American Academy of Cosmetic Dentistry; 2014.

ABOUT THE AUTHOR

Dr. Brauer earned her DDS degree from the University of Missouri, Kansas City, in 2003. She has been practicing dentistry in Arizona for the last 18 years. Since 2006, she’s worked in a dental practice that she opened with her husband, Dr. Howie Brauer. Her focus and passion over the last 10 years has been cosmetic dentistry. She is an accredited member of the American Academy of Cosmetic Dentistry. Outside of work, Dr. Brauer stays busy with the numerous activities that her 3 daughters are involved in. She can be reached at joyfulsmilesaz@gmail.com. 

Disclosure: Dr. Brauer reports no disclosures. 

In 2023, dental caries is still the most common oral disease in children.¹ Not only does this condition affect children’s oral wellness, but it also lowers their self-esteem. This is especially true when dental caries are on the front teeth and easily noticed. The traditional approach is to treat these cases at a more advanced stage of decay. The material of choice was stainless steel crowns, then later tooth-color zirconia crowns. Both children and parents are asking for more natural aesthetics and less invasive treatment instead of amalgam restorations, zirconia, and stainless steel crowns for primary anterior teeth.² 

The good news is that the shift to a much more conservative treatment model is here and has been growing since the 1990s. In addition to treating the caries, our focus is more on early caries detection, nutrition and hydration, risk assessment, and airway evaluation. We also have dental materials like flowable composites with improved filler technology and digital dental technology such as intraoral digital scanners, digital design software, and even AI to restore the teeth and fulfill the 3 basic requirements of function, aesthetics, and biocompatibility.³ 

Recently, VOCO released Admira Fusion Flow, the first-of-its-kind, purely ceramic-based flowable restoration material with no classic monomers. Thanks to the incredibly innovative Nano-ORMOCER technology, the flowable composite has extremely low polymerization shrinkage (2.75% by volume) and particularly low levels of shrinkage stress in comparison to conventional flowable composites. This material achieves a great result thanks to its filler content and excellent surface affinity with complete wetting of the cavity wall. It is very biocompatible and highly resistant to discoloration, which is perfect for pediatric anterior restorations.⁴  

Admira Fusion Flow is known for “flow on demand” because the material becomes flowable only when under pressure or in motion. It has excellent handling characteristics; polishes to a high luster; and, when coupled with high surface hardness, guarantees first-class long-term results.^5,6 This works very well for the flowable composite injectable technique, which is simple and efficient, especially for pediatric cases like the ones below.⁷ 

CASE REPORTS

Case 1

The patient presented at 4 years old with SDF placed to arrest all 6 maxillary anterior teeth (Figure 1). A comprehensive exam, including risk assessment, nutrition, hydration, and airway evaluation, was completed with an intraoral scan (3Shape TRIOS scanner [3Shape]). The dental lab (Esthetics Dental Studio, Cypress, Texas) completed the digital wax-up and fabricated a matrix with a clear PVS material (EXACLEAR [GC]) (Figure 2). The cavity preps were selectively etched with 32% semi-gel phosphoric acid etchant with benzalkonium chloride (BAC) (Uni-etch [BISCO]) for 10 seconds and rinsed with water for 30 seconds, and the enamel was dried with a warm air tooth dryer (A-dec). Admira Bond (VOCO) was placed as the adhesive, thinned with the warm air tooth dryer, and light-cured for 10 seconds with an LED curing light (VALO [Ultradent Products]). Creative Color Pink Opaque (Cosmedent) was applied in 1.0-mm layers to block out the discoloration and light-cured for 10 seconds (Figure 3). 

Figure 1. Preoperative view of the maxillary primary incisors and canines of a 4-year-old patient with extensive caries arrested with SDF.

Figure 2. A clear PVS matrix was fabricated to replicate the digital wax-up intraorally.

Figure 3. Existing discoloration blocked out with Creative Color Pink Opaque (Cosmedent).

Figure 4. Immediately after the clear matrix was removed.

A clear PVS matrix was placed after Teflon tape was used to cover the primary premolars. Admira Fusion Flow was injected using the matrix and was light-cured for 10 seconds with an LED curing light. The clear PVS matrix was then removed (Figure 4). The composite was contoured and shaped with an OS1 carbide finishing bur (Brasseler USA). The last step included placing a clear resin coat of varnish (Dreve [anax USA]) over the entire restoration with a microbrush and then light curing for 10 seconds. The oxygen-inhibiting layer was removed by applying DeOx (Ultradent Products) and then light-cured for 10 seconds and rinsed with water for 30 seconds. The final restoration (Figure 5) demonstrates the natural effect of the material with a final finish and high gloss. 

Figure 5. The completed maxillary primary restorations.

Figure 6. Retracted view at 18 months postoperative.

Figure 7. Smile view at 18 months post-op.

Figure 8. Retracted view at 30 months post-op.

Figure 9. Smile view at 30 months post-op.

Figure 10. Retracted view at 36 months post-op.

Figure 11. Smile view at 36 months post-op.

The patient came back for followup at 18 months (Figures 6 and 7), again at 30 months (Figures 8 and 9), and at 36 months (Figures 10 and 11).  

Case 2 

The mother of a 3-year-old patient had concerns about his worn primary dentition, especially the anterior (Figure 12). A comprehensive exam, including dental caries risk assessment, nutrition, hydration, tongue posture, and airway evaluation, was completed with an intraoral scan (TRIOS scanner). The patient was given oral myofunctional exercises to practice at home, nasal hygiene instruction to enhance nasal breathing, and mouth taping at night. The dental lab (Esthetics Dental Studio) completed the digital wax-up and fabricated the clear matrix with clear PVS (EXACLEAR). The teeth were selectively etched with 32% semi-gel phosphoric acid etchant with BAC (Uni-etch) for 10 seconds and rinsed with water for 30 seconds, and the enamel was dried with a warm air tooth dryer (A-dec). Admira Bond was placed as the adhesive, thinned with the warm air tooth dryer, and light-cured for 10 seconds with an LED curing light (VALO). Creative Color Pink Opaque was applied in 1.0-mm layers to block out the discoloration and light-cured for 10 seconds. A clear PVS matrix was placed after Teflon tape was used to cover the primary canines. Admira Fusion Flow was injected using the matrix and was light-cured for 10 seconds with an LED curing light, and the clear PVS matrix was removed. The composite was contoured and shaped with an OS1 carbide finishing bur (Brasseler USA). The last step included placing a clear resin coat of varnish (Dreve) over the entire restoration with a microbrush, which was light-cured for 8 seconds. The oxygen-inhibiting layer was removed by applying DeOx, light-cured for 10 seconds, and then rinsed with water for 30 seconds. The final restoration (Figure 13) demonstrates the natural effect of the material and the final finish and high gloss. 

Figure 12. Before the composite bonding.

Figure 13. After the composite bonding on teeth D to G.

CLOSING COMMENTS 

With the advancement of biocompatible flowable composites, clinicians now have choices when treating pediatric patients with primary caries in the anterior restorations to obtain function, aesthetics, and biocompatibility. This will help patients to keep healthy teeth and confident smiles. The injectable technique with flowable composite is predictable, efficient, and minimally invasive, which means happier pediatric dental patients and parents.

REFERENCES

1. Beltrán-Aguilar ED, Barker LK, Canto MT, et al; Centers for Disease Control and Prevention (CDC). Surveillance for dental caries, dental sealants, tooth retention, edentulism, and enamel fluorosis—United States, 1988-1994 and 1999-2002. MMWR Surveill Summ. 2005 Aug 26;54(3):1-43. 

2. Hyson JM Jr. Amalgam: Its history and perils. J Calif Dent Assoc. 2006;34(3):215–29. 

3. Terry DA. Direct applications of a nanocomposite resin system: Part 1—The evolution of contemporary composite materials. Pract Proced Aesthet Dent. 2004 Jul;16(6):417–22. 

4. Jefferies SR. The art and science of abrasive finishing and polishing in restorative dentistry. Dent Clin North Am. 1998;42(4):613–27.  

5. Hervás-García A, Martínez-Lozano MA, Cabanes-Vila J, et al. Composite resins. A review of the materials and clinical indications. Med Oral Patol Oral Cir Bucal. 2006;11(2):E215-20. English, Spanish. 

6. Hosoya Y, Shiraishi T, Oshiro M, et al. Color characteristics of resin composites in different color modes and geometries. J Oral Sci. 2009;51(1):123–30. doi:10.2334/josnusd.51.123 

7. Terry DA, Powers JM, Mehta D, et al. A predictable resin composite injection technique, part 2. Dent Today. 2014;33(8):12. 

ABOUT THE AUTHOR

Dr. To graduated from the University of Texas Health Science Center in San Antonio in 2010 with distinction in research. She is the founder of Katie To Center of Integrative Wellness and Cosmetic Dentistry, KT Dental Seminars, and the Wellness Dentist Institute. She has maintained a private practice in Katy, Texas, since 2015, emphasizing cosmetic and wellness dentistry. She can be reached at (281) 392-8450, via email at drkatie@thewellnessdentist.com, or at the website thewellnessdentist.com. 

Disclosure: Dr. To has no financial interest in any of the companies mentioned in this article but did receive compensation from VOCO for writing this article. 

Three-dimensional printing in dentistry has seen accelerating growth over the past several years with emerging applications in definitive restorations. Not only is the technology becoming increasingly cost-effective and user-friendly, but novel photopolymer resins are beginning to rival conventional materials in their durability and aesthetics, with some printed materials exceeding the mechanical properties of milled ceramics and hybrid ceramics.^1,2 

Printed restorations are a progressive solution to perform conservative indirect quadrant dentistry using inlays and onlays in a single visit. Partial-coverage restorations enable conservation of the remaining tooth structure, providing greater durability of restorations compared to full-coverage crown preparations that potentially unnecessarily remove healthy tooth structure.^3-5 Many dental practices, however, avoid inlay/onlay restorations due to various challenges associated with both indirect and direct restorations. Typical indirect workflows require multiple office visits, including direct composite temporization while the restoration is being fabricated at a dental lab. While indirect restorations allow the use of more durable restorative materials, direct workflows are typically preferred due to fewer necessary office visits. As for direct composite restorations, many clinicians view them as requiring a more meticulous technique compared to the alternative of full-coverage crowns. With direct composite restorations, anatomical contacts and contours must be precisely hand-sculpted into the material. This can be particularly challenging with larger restorations when more material is removed during tooth preparation. Additionally, as the geometry of a tooth preparation increases in complexity, the failure rate with direct composite increases by 30% to 40% for every additional surface added to the restoration.⁶ A recent systematic review and meta-analysis showed that indirect onlay restorations made of resin were equally durable to ceramic restorations. Both performed dramatically better compared to direct resin restorations.⁷ 

Direct resins have 2 major drawbacks related to their polymer chemistry. First, due to their cross-linking mechanism, direct resins typically have a bond conversion ratio for their methacrylate esters of roughly 60%, meaning they are never fully cured.⁸ Several factors are involved in this low level of methacrylate bond conversion, including curing time, distance of the curing light from the tooth surface, and thickness of the resin being cured.⁹ Because direct composite is inadequately cross-linked, the mechanical properties are not fully optimized, resulting in accelerated wear and a relatively weak fracture-toughness performance. One study that looked at the fracture toughness of 6 different direct resin materials found the average fracture toughness to be around 1 K_Ic.¹⁰ This is far lower compared to natural tooth structure, which has a fracture toughness of around 2 K_Ic.¹¹ Fracture toughness values are extremely important, and in a recent systematic review, fracture toughness was the test that most closely correlated with clinical longevity.¹² The fracture toughness of Ceramic Crown material (SprintRay) is 2.1 K_Ic, which is very close to natural tooth structure. 

Three-dimensionally printed resins have incredible mechanical properties due to their novel polymer chemistry and functionalized filler particles that are cured using high heat and powerful ultraviolet sources according to validated protocols. This enables 3D printed restorations to achieve above 90% bond conversion, significantly improving strength and wear resistance while not inhibiting long-term bond strength.¹³ In a recent study, 3D printed denture teeth outperformed premium carded denture teeth in simulated wear testing against zirconia antagonists.¹⁴ 

Another significant disadvantage of direct resin is polymerization shrinkage stress. Direct resins cured in situ have been shown to generate stress on the walls of the preparation due to polymer-
ization shrinkage. This is suspected to contribute to mechanical failure of direct restorations and can also cause gap formation resulting in microleakage and recurrent decay. Indirect resin restorations have been shown to almost eliminate this stress completely on the bond as any polymerization shrinkage happens extraorally and luting resin fills any voids between the restoration and preparation walls.^15,16 

Due in part to fabrication and material performance challenges, only 6% of dental restorative treatments in the United States involve inlays and onlays. Milled composites were promised as an ideal material in these indications but unfortunately suffered from common debonding issues and high-water uptake, based in part on their old legacy resin chemistry. These debonding failures occur with milled resin partially due to the complete bond conversion within their polymer structures. The lack of residual methacrylate groups makes these materials difficult to bond, resulting in adhesive failures at the luting interface.^17,18 Furthermore, many milled resins are based on older resin chemistry from the 1950s, leading to accelerated water uptake that further exasperated deboning issues clinically.¹⁹ Contrastingly, studies have demonstrated that bonding to 3D printed restorations exhibits excellent initial bond strength that actually increases over time.²⁰   

Several novel 3D printing materials, such as Ceramic Crown resin, contain greater than 50% ceramic nanoparticles, enabling them to meet ADA requirements for definitive ceramic restorations. As such, these can be billed using CDT codes previously reserved for zirconia or lithium disilicate. Ceramic Crown resin is an FDA-cleared Class II resin for 3D printing definitive full crowns, inlays/onlays, and veneers. The material has high strength and wear resistance, and it is radiopaque for clear visibility on radiographs for monitoring during routine recall appointments. The resin has a flexural strength of 150 +/- 25 MPa, which is comparable to leucite glass ceramics (150 MPa), and its shear bond strength is comparable to lithium disilicate.²¹ Ceramic Crown resin has a very low water absorption, reducing its tendency to age and stain, while its smooth surface minimizes plaque accumulation. 

In the presented case, 3D printing enabled a full quadrant of inlay/onlay restorations to be prepped, designed, and delivered within a single 2-hour visit. In a team-driven approach, the scanning, design, and restoration fabrication were all performed by an assistant. This is a significant time savings compared to direct composite restorations where a full quadrant might take a full hour of meticulous attention by the clinician. Three-dimensional printing facilitates single-appointment inlay/onlay restorations with a workflow that can largely be delegated to the team.

CASE REPORT

A 35-year-old female patient presented for a routine prophylaxis appointment after an 18-month delay due to the pandemic and other factors. During the hygiene appointment, she indicated sensitivity on the posterior left mandibular teeth that had been present for some time. Examination of the bite-wing radiographs taken at the appointment demonstrated recurrent decay associated with the restorations in teeth Nos. 18 to 20. A clinical exam noted tooth No. 18 had a large MO amalgam with marginal breakdown on the occlusal surface and recurrent decay. Tooth No. 19 had separate DO and MO amalgam restorations with a dark area under the central fossa, and a crack was noted in the mid-buccal extending from the gingival margin to the area noted at the central fossa. Tooth No. 20 had an MOD composite restoration with dark shading on the distal occlusal and marginal breakdown on the mesial portion (Figure 1). The patient indicated that she would be traveling in a few days and inquired if the treatment could be done that day and completed before her trip. Based on the clinical findings, the patient opted for single-visit delivery of inlay/onlays on teeth Nos. 18 to 20 utilizing in-office 3D printing. She was informed that the crack on tooth No. 19 may necessitate a larger restoration, but that would be determined following the removal of the current restorations and decay. The patient agreed to treatment, and treatment was initiated. 

Figure 1. Clinical presentation of a failing MOD composite in tooth No. 20, MO and DO amalgams in No. 19, and a large MO amalgam in No. 18.

Figure 2. Clinical picture following removal of the failing restorative material and decay with preparation for inlay restorations on Nos. 18 and 20 with an onlay on tooth No. 19.

Local anesthetic was placed using an IAN block and mental injection. A rubber dam was applied, and the amalgam and composite were removed from the teeth with a carbide bur in a high-speed handpiece. Due to the crack on the buccal aspect of No. 19, the distal-buccal cusp was compromised, which necessitated its removal from the tooth. No pulpal exposure was noted following removal of the cusp. Recurrent decay was removed from the 3 teeth, and an OM inlay was planned for No. 18, an MODB onlay was planned for No. 19, and an MOD inlay was planned for No. 20. Tetric EvoFlow (Ivoclar Vivadent), a flowable composite, was placed to block out any undercuts on the preparations and cover the pulpal floor at the missing cusp on No. 19. This was then light-cured, and the preparations were refined (Figure 2).

The procedure was handed off to the dental assistant to scan, design, and print the restorations. The rubber dam was removed, and the quadrant was scanned with an intraoral scanner (Primescan [Dentsply Sirona]) (Figure 3). Within exocad (exocad America), the restoration margins were identified, and offset parameters were set for a 120-µm cement gap with a margin ramp of 200 µm to generate the restorations (Figure 4). Printing would be performed on the Pro 55S 3D printer (SprintRay) utilizing A1 Ceramic Crown resin (SprintRay) with a 100-µm print layer height. The virtual design restorations were completed and ready to be printed (Figures 5 to 8).

Figure 3. Virtual model of the prepared teeth ready for virtual design of the restorations in preparation for 3D printing.

Figure 4. The planned restorations have been virtually designed on teeth Nos. 18 to 20.

Figure 5. Buccal view of the individual restorations without the virtual model.

Figure 6. Occlusal view of the individual restorations without the virtual model.

Figure 7. Lingual view of the individual restorations without the virtual model.

Figure 8. Intaglio view of the individual restorations without the virtual model.

The exported STL files for these restorations were imported into RayWare Cloud (SprintRay), where automated algorithms determined the print layout and support structures in 100-µm layers in crown mode using the crown kit, which would allow printing of the restorations in 10 minutes (Figures 9 and 10). RayWare is automated dental 3D printing software that takes the designs from exocad or other similar design software and sets it for printing in the various SprintRay printers available. 

Figure 9. Planned restorations were placed on the build platform for preview in RayWare (SprintRay), and AI nesting with a final check was performed.

Figure 10. Side view on the virtual positioning of the restorations with supports on the build platform for preview in RayWare.

Following the printing of the restorations, which was accomplished in 10 minutes, the restorations were removed from the build platform and then spray washed for 20 seconds (Figure 11). The assistant then placed the restorations into the ProCure 2 unit (SprintRay) to cure the resin using the programmed settings, which was finished in 6 minutes. The ProCure 2 delivers a concentrated 385-nm light, which generates heat locally on each part, accelerating resin curing and thus decreasing processing time. The supports were removed from the restorations, and surfaces were polished to achieve the desired contours. The assistant next applied light staining to the pits and fissures to simulate a natural appearance using IPS Empress Direct Color (Ivoclar) and light cured the restorations. Then the restorations were taken to the operatory and trial-seated in the preparations to confirm fit, and the doctor was called back to the operatory.

Figure 11. The restorations following 3D printing, with the supports present after separation from the plate, and ready for finishing.

Figure 12. Restorations to the prepared teeth following luting and finishing of the margins after occlusal adjustment.

Figure 13. Radiograph of the luted restorations.

The doctor checked the proximal contacts of the restorations with floss and an explorer and also checked the marginal fit. The restorations were removed, and a rubber dam was placed. Selective etching with a 37% phosphoric acid gel was performed on the enamel margins. The interior of the restorations (intaglio surface) was treated by sandblasting it with 50-µm alumina oxide particles to roughen the surface and increase bondability. Adhese Universal adhesive (Ivoclar) was applied to the enamel, dentin, and resin blockout on the teeth and to the interior surfaces of the restorations and was not light-cured. Variolink Esthetic DC (Ivoclar), a light-cure and dual-cure luting composite for adhesive cementation of dental restorations, was applied to the preparation surfaces on the teeth. The restorations were then seated and tack-cured for 5 seconds for each tooth. The excess luting composite was cleared from the margins with a brush and interproximally with floss. The restorations were then light-cured from the occlusal, buccal, and lingual surfaces for 30 seconds per surface per tooth. The margins were checked for any residual luting resin with an explorer and floss. Occlusion was checked and did not require any adjustments (Figure 12). A bite-wing radiograph was taken to confirm fit and lack of residual luting resin (Figure 13). The cement layer between the intaglio surface of the restorations and the preparation was minimal, allowing the strength of the Ceramic Crown resin to provide maximum benefits and durability. 

The restorations were placed a little more than one year ago, and on subsequent recall prophy appointments, one being at the one-year anniversary of restoration placement, demonstrated no occlusal or marginal wear. The patient reported no sensitivity at any point following restoration placement. 

CONCLUSION

The benefit of in-office 3D printing is that restorations can be completed in a single visit, as demonstrated by the case presented. Although the total treatment time in the office was 2 hours, a majority of the work in that time was performed by trained staff, highlighting the effectiveness of team-driven care. The practitioner’s time involved preparation of the teeth and luting of the finished restorations—approximately 30 to 45 minutes of the total treatment time. Team members scanned the preparations, imported the data into the software, utilized the AI capabilities of the software to design the restorations, printed the restorations, finished them, and verified seating before having the practitioner lute those restorations. Thus, use of this approach provides practical care in a single visit without a large time involvement by the practitioner, freeing him or her to treat other patients while the restorations are being fabricated.

The Ceramic Crown resin has been shown to be a durable material with good wear characteristics that provides an aesthetic restoration without the need for involvement with an outside lab and the increase in costs and turnaround time involved. Additionally, patients ideally would like one-stop shopping where treatment can be accomplished in a single visit, freeing up their schedules for other parts of life, such as work and family.

REFERENCES

1. Zimmermann M, Ender A, Egli G, et al. Fracture load of CAD/CAM-fabricated and 3D-printed composite crowns as a function of material thickness. Clin Oral Investig. 2019;23(6):2777–84. doi:10.1007/s00784-018-2717-2

2. Corbani K, Hardan L, Skienhe H, et al. Effect of material thickness on the fracture resistance and failure pattern of 3D-printed composite crowns. Int J Comput Dent. 2020;23(3):225–33. 

3. Donovan TE. Longevity of the tooth/restoration complex: a review. J Calif Dent Assoc. 2006;34(2):122–8.   

4. Dennison JB, Hamilton JC. Treatment decisions and conservation of tooth structure. Dent Clin North Am. 2005;49(4):825–45. doi:10.1016/j.cden.2005.05.007 

5. Wayakanon K. Partially coverage restoration: an esthetically conservative treatment for a complex cavity restoration. Open J Stomatol. 2017;7(4):234–41. doi:10.4236/ojst.2017.74017

6. Opdam NJ, van de Sande FH, Bronkhorst E, et al. Longevity of posterior composite restorations: a systematic review and meta-analysis. J Dent Res. 2014;93(10):943–9. doi:10.1177/0022034514544217 

7. Bustamante-Hernández N, Montiel-Company JM, Bellot-Arcís C, et al. Clinical behavior of ceramic, hybrid, and composite onlays. A systematic review and meta-analysis. Int J Environ Res Public Health. 2020;17(20):7582. doi:10.3390/ijerph17207582 

8. Ribeiro BC, Boaventura JM, Brito-Gonçalves Jd, et al. Degree of conversion of nanofilled and microhybrid composite resins photo-activated by different generations of LEDs. J Appl Oral Sci. 2012;20(2):212–7. doi:10.1590/s1678-77572012000200015 

9. Barakah H. Effect of different curing times and distances on the microhardness of nanofilled resin-based composite restoration polymerized with high-intensity LED light curing units. Saudi Dent J. 2021;33(8):1035–41. doi:10.1016/j.sdentj.2021.05.007

10. Watanabe H, Khera SC, Vargas MA, et al. Fracture toughness comparison of six resin composites. Dent Mater. 2008;24(3):418–25. doi:10.1016/j.dental.2007.06.018 

11. Yahyazadehfar M, Ivancik J, Majd H, et al. On the mechanics of fatigue and fracture in teeth. Appl Mech Rev. 2014;66(3):0308031-3080319. doi:10.1115/1.4027431 

12. Heintze SD, Ilie N, Hickel R, et al. Laboratory mechanical parameters of composite resins and their relation to fractures and wear in clinical trials—a systematic review. Dent Mater. 2017;33(3):e101-e114. doi:10.1016/j.dental.2016.11.013 

13. Lim JH, Lee SY, Gu H, et al. Evaluating oxygen shielding effect using glycerin or vacuum with varying temperature on 3D printed photopolymer in post-polymerization. J Mech Behav Biomed Mater. 2022;130:105170. doi:10.1016/j.jmbbm.2022.105170 

14. Pham DM, Gonzalez MD, Ontiveros JC, et al. Wear resistance of 3D printed and prefabricated denture teeth opposing zirconia. J Prosthodont. 2021;30(9):804–10. doi:10.1111/jopr.13339 

15. Dejak B, Młotkowski A. A comparison of stresses in molar teeth restored with inlays and direct restorations, including polymerization shrinkage of composite resin and tooth loading during mastication. Dent Mater. 2015;31(3):e77-87. doi:10.1016/j.dental.2014.11.016 

16. Ausiello P, Ciaramella S, Fabianelli A, et al. Mechanical behavior of bulk direct composite versus block composite and lithium disilicate indirect Class II restorations by CAD-FEM modeling. Dent Mater. 2017;33(6):690-701. doi:10.1016/j.dental.2017.03.014 

17. Wierichs RJ, Kramer EJ, Reiss B, et al. A prospective, multi-center, practice-based cohort study on all-ceramic crowns. Dent Mater. 2021;37(8):1273–82. doi:10.1016/j.dental.2021.04.005 

18. Awad MM, Albedaiwi L, Almahdy A, et al. Effect of universal adhesives on microtensile bond strength to hybrid ceramic. BMC Oral Health. 2019;19(1):178. doi:10.1186/s12903-019-0865-7 

19. Schepke U, Filius D, Lohbauer U, et al. Dimensional changes of CAD/CAM polymer crowns after water aging—an in vitro experiment. J Mech Behav Biomed Mater. 2022;128:105109. doi:10.1016/j.jmbbm.2022.105109 

20. Lankes V, Reymus M, Liebermann A, et al. Bond strength between temporary 3D printable resin and conventional resin composite: influence of cleaning methods and air-abrasion parameters. Clin Oral Investig. 2023;27(1):31-43. doi:10.1007/s00784-022-04800-7 

21. Jurado CA, Ahmed AS, Lawson NC, et al. Fracture resistance of zirconia surveyed crowns with four different occlusal rest seat designs. J Prosthodont. 2023. doi:10.1111/jopr.13737.

ABOUT THE AUTHORS

Dr. Renne is the founder of the MOD Institute, where he instructs clinicians on the application of the latest digital technologies with a focus on minimal prep techniques to preserve natural dentition. With 3 years of dental 3D printing experience, he has delivered more than 1,000 printed restorations, including veneers, inlays, onlays, and crowns. Dr. Renne can be reached at dr.renne@themodinstitute.com. 

Dr. Kurtzman is in private general dental practice in Silver Spring, Md, a former assistant clinical professor at the University of Maryland in the Department of Restorative Dentistry and Endodontics, and a former American Academy of Implant Dentistry Implant MaxiCourse assistant program director at the Howard University College of Dentistry. He has lectured internationally on the topics of restorative dentistry, endodontics, implant surgery, prosthetics, removable and fixed prosthetics, and periodontics and has published more than 830 articles globally, as well as several e-books and textbook chapters. He has earned Fellowship in the AGD; American College of Dentists; International Congress of Oral Implantology (ICOI); Pierre Fauchard Academy; Academy of Dentistry International; and the International Academy of Dental Facial Esthetics, Mastership in the AGD and ICOI; and Diplomate status in the ICOI, American Dental Implant Association, and the International Dental Implant Association. Dr. Kurtzman has been honored to be included in Dentistry Today’s Leaders in CE listings annually since 2006. He can be reached via email at dr_kurtzman@maryland-implants.com.  

Disclosure: Dr. Renne reports no disclosures. Dr. Kurtzman received compensation for writing this article.

When it comes to executing a smile makeover, dentists have a variety of direct and indirect techniques to consider.¹ With the emphasis today on minimally invasive techniques to preserve tooth structure and demand from patients for a natural-looking treatment result, direct resin composites have catapulted to the forefront as a method to save as much tooth structure as possible while providing the patient with long-lasting, highly aesthetic restorations that blend seamlessly in the mouth.^2-4 Whether repairing enamel defects or a fracture on a single central; closing a diastema; or improving aesthetics by altering tooth size, shape, color, length, or alignment, chairside direct composite resin restorations provide the clinician and patient with a restorative option that is not only highly aesthetic and durable but also the least invasive, the most time-efficient, and more cost-effective.

However, the direct composite restorative option has historically challenged clinicians in terms of its technique sensitivity, aesthetic predictability, and often time-consuming nature, potentially leading to aesthetically disappointing results. To avoid these pitfalls, clinicians often turn to an indirect approach, prescribing minimally invasive or no-prep veneers. However, there are times when patients can neither afford the expense nor the time for the fabrication of indirect porcelain restorations and desire a chairside solution that not only meets these limitations but also preserves natural tooth structure.

Fortunately, advances in resin composite materials and adhesive techniques offer the ability to correct defects in the anterior arch chairside that ensure optimal aesthetics and strength as well as wear resistance.⁵ One of the most common treatment options for these patients is the direct composite veneer. These restorations have proven to be functional, highly aesthetic, and long-lasting ones that mimic natural dental tissues in the anterior region.

This case report describes a step-by-step smile makeover with direct composite veneers to correct defects on the central incisors and the tooth shapes, length, and shade of teeth Nos. 4 to 13.

CASE REPORT

A healthy 32-year-old male presented to the practice with the chief complaint that he disliked the shapes of his asymmetric teeth and lacked tooth display when smiling or speaking (Figure 1). As a recovered drug addict with plans to marry in the near future, he wanted a bright new smile for his wedding day and to regain his self-confidence. However, he was adamant that saving natural tooth structure and his limited finances must be top considerations for any treatment plan presented. 

Figure 1. Preoperative photograph of a patient concerned about his lack of tooth display when smiling, the color and shape of his teeth, and the chipping of his central incisors.

Figure 2. An intraoral scan of both arches revealed a constricted bite with visible wear on teeth Nos. 7 to 10 and chipping on teeth Nos. 8 and 9 caused by intrusion with the patient’s lower teeth and a large diastema.

Initial examination and intraoral scans of both arches revealed a constricted bite with visible wear on teeth Nos. 7 to 10 and chipping on Nos. 8 and 9 caused by intrusion with the patient’s lower teeth (Figure 2). He had a large, 4-mm diastema between teeth Nos. 8 and 9 and saturated chroma from Nos. 6 to 11. Radiographs showed no decay in the anterior arch. Periodontal probing revealed pockets of 2 to 3 mm with no bleeding. The patient was in good health with no allergies or medical concerns.

Treatment Plan

To preserve his natural tooth structure and meet his financial goals, direct composite veneers were prescribed for teeth Nos. 4 to 13.⁵ Prior to restorative treatment, however, it would be necessary to treat the intrusive interference that was causing wear and chipping of his maxillary anterior teeth to ensure the longevity of the final restorations (Figure 3). Clear aligner therapy (Invisalign [Align Technology]) was prescribed for both arches to slightly flare the anterior teeth forward 1.5 to 2.0 mm, rotate tooth No. 10 into proper position for composite layering, and help close the diastema as much as possible while intruding the lower anterior teeth to create a non-intrusive anterior relationship. An intraoral scan (iTero [Align Technology]) of the patient’s upper and lower jaw was performed, and a series of aligners were ordered. The patient was instructed to change the aligners each week for the next 15 weeks to complete the therapy (Figure 4).

Figure 3. Prior to direct resin composite restorative treatment for veneers on teeth Nos. 4 to 13, clear aligner therapy was prescribed for both arches to flare the anterior teeth forward to create a non-intrusive relationship.

Figure 4. After 15 weeks of aligner ther- apy, the anterior relationship had been cor- rected, and the 4-mm diastema between teeth Nos. 8 and 9 closed to 0.5 mm.

The goal of the final direct composite restorative treatment was to bring his smile closer to golden proportions by lengthening his central incisors to match the length of teeth Nos. 6 and 11 and lengthen Nos. 7 and 10 to create a 0.5-mm step from the centrals to the laterals and permanently close the diastema.

Treatment

Once the orthodontic therapy was completed to provide a corrected anterior relationship and reduce the diastema from 1 mm to 0.2 mm, intraoral scans and a series of photos of both arches were taken (Figures 5 to 10) to fabricate a diagnostic wax-up for ideal tooth contour, shape, and occlusion. Once the patient approved the proposed treatment plan, a silicone putty matrix was fabricated and cut back to use as a lingual guide for tooth lengthening during the direct composite application. Because the index is the exact length and form of the patient-approved diagnostic wax-up, using the silicone index will guide the clinician in transferring the desired final outcome to the mouth.

Figures 5 to 10. A series of treatment photos and intraoral scans of both arches were taken to fabricate a chairside diagnostic wax-up and create a silicone putty matrix to guide the application of direct composite veneers.

The patient was anesthetized with Lidocaine 2% with 1:100,000 epinephrine. Critical to aesthetic success when using the direct composite method is selecting the correct tooth shade. Shade analysis and matching should be completed while the patient’s teeth are hydrated and prior to isolation as dehydration results in teeth appearing whiter than if hydrated. A highly versatile composite (Inspiro [Edelweiss]) was chosen for this case due to its multiple shade options and ease of use. Skin and body shade tabs with glycerine were used to appropriately match the teeth to the proposed shade. Glycerine allows hydration between the tabs to give the true essence of how the shade will look in a “wet environment” like the mouth. The shades chosen for the layering technique were dentin shade Bi1 and enamel skin shade white and skin shade bleach to brighten and whiten the patient’s smile.

The patient was retracted (OptraGate [Ivoclar]), and the fit of the putty matrix was confirmed prior to the start of bonding. Teeth Nos. 4 to 13 were air abraded with aluminum oxide at 40 psi (Figure 11), etched with 37% phosphoric acid for 20 seconds, and then rinsed thoroughly. Once a frosty appearance was confirmed, a bonding agent (OptiBond Universal [Kerr]) was applied and cured after airing the solvent. 

Figure 11. Prior to composite application, teeth Nos. 4 to 13 were air abraded with aluminum oxide at 40 psi, etched with 37% phosphoric acid for 20 seconds, and then rinsed thoroughly.

Figure 12. It was critical to establish the correct length, shape, and contour for the central incisors as a guide to layering the remaining teeth. Here, a dentin layer was applied to tooth No. 8 to establish the exact length envisioned.

For this case, it was critical to first layer the 2 central incisors to establish the exact shape, contour, and aesthetics that would guide layering of the remaining teeth.^6-8 Beginning with tooth No. 8, a thin layer of skin shade was applied onto the lingual matrix and placed onto the tooth. The layer was held in place and cured. Next, a thin layer of Bi1 dentin was placed over the facial aspect and light cured to establish the correct length and desired shape (Figure 12). In order to establish the final white color of the composite veneers, the last layer placed was the skin bleach shade, then it was cured. A cutback window technique was used to create the space needed to apply tints and chromatic enamel shades. A fine diamond chamfer bur angled toward the cervical was used to create a bevel-like window 0.5 mm to 1 mm from the incisal edge. This technique provided a more natural appearance of the composite restoration and gave it greater dimension. Tint shades (inspiro Effect Shades Ice and Azur [Edelweiss]) were applied to the incisal edges and then covered with a thin layer of achromatic enamel (inspire Skin White [Edelweiss]). Once the central incisors were finalized, veneering of the remaining teeth followed the same procedure (Figure 13). 

Figure 13. Once the shape, contour, and color of the central incisors were established, veneering of the remaining teeth was performed.

Figure 14. The veneered teeth were shaped using a disc, and the application of secondary and tertiary anatomies was completed.

The teeth were contoured and shaped using a disc (Cosmedent), and secondary and tertiary anatomies were placed (Figure 14). Then final polishing was performed using polishing paste (Enamelize [Cosmedent]) and polishing discs (FlexiBuff [Cosmedent]). 

Figures 15 to 20. Final occlusion was checked, and protrusive and lateral excursions were verified. The patient was pleased with the final outcome.

Final occlusion was checked, all protrusive and lateral excursions were verified, and all contacts were flossed. The patient was pleased with the final outcome (Figures 15 to 20).

CONCLUSION

Multi-layered composite resin restorations for addressing patients’ aesthetic and financial concerns are a conservative approach that can deliver truly lifelike restorations. Although direct resin composite veneers can challenge the most seasoned clinician, their execution helps develop a deep understanding of tooth anatomy: tooth contours, shape, and color. With new developments in material formulations, today’s direct composite resins offer a predictable and reliable alternative to more invasive and costly indirect restorative approaches to arrive at the patient’s vision of an ideal smile.

REFERENCES

1. Fahl N Jr. Direct-indirect composite veneers: Balancing esthetics and minimal intervention. Dental Economics. February 14, 2023. https://www.dentaleconomics.com/science-tech/article/14288234/directindirect-composite-veneers-balancing-esthetics-and-minimal-intervention

2. Korkut B. Smile makeover with direct composite veneers: A two-year follow-up report. J Dent Res Dent Clin Dent Prospects. 2018;12(2):146-151. doi:10.15171/joddd.2018.023 

3. Heintze SD, Rousson V, Hickel R. Clinical effectiveness of direct anterior restorations—a meta-analysis. Dent Mater. 2015;31(5):481–95. doi:10.1016/j.dental.2015.01.015

4. Yesil ZD, Alapati S, Johnston W, et al. Evaluation of the wear resistance of new nanocomposite resin restorative materials. J Prosthet Dent. 2008;99(6):435–43. doi:10.1016/S0022-3913(08)60105-5 

5. Fortin D, Vargas MA. The spectrum of composites: new techniques and materials. J Am Dent Assoc. 2000;131 Suppl:26S-30S. doi:10.14219/jada.archive.2000.0399 

6. Dietschi D, Fahl N Jr. Shading concepts and layering techniques to master direct anterior composite restorations: an update. Br Dent J. 2016;221(12):765–71. doi:10.1038/sj.bdj.2016.944

7. Fahl N Jr. Mastering composite artistry to create anterior masterpieces, part 1. J Cosmetic Dent. 2010;26(3):56-68. 

8. Fahl N Jr. Mastering composite artistry to create anterior masterpieces, part 2. J Cosmetic Dent. 2010;26(4):42-55. 

ABOUT THE AUTHOR

Dr. Desai is a cosmetic dentist practicing in Newport Beach, Calif. She is the founder of Luminous Smiles, an interdisciplinary dental practice focusing on rejuvenating patient’s lives through their smile. Dr. Desai received her DDS from the University of Southern California in 2008 and was selected to become a member of the national dental society, Omicron Kappa Upsilon. Dr. Desai returned to her Alma Mater in 2018 to serve as a clinical adjunct professor until 2020. She has been recognized as a Top Dentist locally for 4 consecutive years and was recognized nationally as a Top 40 under 40 Dentist in 2020. Dr. Desai is a proud accredited member of the American Academy of Cosmetic Dentistry and has published numerous articles highlighting her patient cases in nationally and internationally circulated dental publications. She can be reached via email at drdesai@luminoussmiles.com.  

Disclosure: Dr. Desai reports no disclosures.  

Certain glass polyalkenoate (ionomer) systems have proven to be excellent dentin replacement liners and bases for decades in biomimetic stratification tooth repair.¹ The resin-modified glass-ionomer cements, particularly, are well suited to that purpose. Now there is a worthy alternative. Since its introduction in January 2021, TheraBase (BISCO) has been proving itself as an excellent radiopaque, bonded dentin replacement base/liner.² The company refers to the material as a “dual-cured, calcium- and fluoride-releasing base, self-adhesive base/liner.” TheraBase is packaged in a double-barrel syringe with a self-mixing delivery tip that is used to inject material directly into a cavity preparation. Another method of delivery comes from mixing pad spatulation and using the AccuDose syringe system (CENTRIX). Simulated delivery of the material and photo-polymerization in an extracted molar is shown in Figures 1 to 3.  

Figure 1. Beginning injection with the double-barreled delivery/mixing system in an extracted tooth simulation.

Figure 2. Injection of TheraBase (BISCO) to overfill to serve as a dentin/enamel interim restoration.

Figure 3. Photo-polymerization followed by chemical curing of the material. Trimming with appropriate burs followed.

The manufacturer’s material safety data sheets fully describe the makeup of TheraBase, which consists of tricalcium silicate (Ca₃SiO₅), dicalcium silicate (Ca₂SiO₄), tricalcium aluminate (Ca₃Al₂O₅), and calcium aluminoferrite (Ca₄Al_nFe_2-nO₇) and a photopolymerizing resin component.^3,4 MDP (10-methacryloyloxydecyl dihydrogen phosphate) is also included as a bonding agent for chemical adhesion to tooth substrates.^5,6

Currently, calcium silicate/calcium aluminate cement materials offer an alternative to the glass-ionomer systems for dentin replacement liners/bases.⁷ BISCO’s “Thera” products are examples of such liner and base materials. In more than 2 years of clinical use in both primary and permanent teeth, we have discovered that, in addition, TheraBase can also be used as an interim restorative material, replacing both dentin and enamel. Traditionally, zinc oxide/eugenol (ZOE), reinforced ZOE, and many of the glass-ionomer cement systems are used in that manner. TheraBase is now proving itself to be a worthy alternative. Following the repair of dozens of primary molars meeting certain criteria, permanent teeth needing “temporization” observations in clinical practice show that the material does not exhibit early wear, fractures, or erosion. This article presents typical examples of such uses of this material.

TECHNIQUE FOR PLACEMENT

• Cut a cavity preparation in the same design for resin-based composite or glass-ionomer cement, including mechanical undercutting.  
• Clean the preparation of all debris with water spray.
• Remove excess moisture with air spray, there is no need to completely dry surfaces to the point of desiccation.
• In the mouth, disinfect the cavity preparation with a solution such as Gluma (Kulzer) or MicroPrime (Zest Dental Solutions).^8,9
• Mix and inject material to overfill from the bottom up in the preparation and with care to avoid air entrapment.
• Apply the light beam for 20 seconds (no need to inject and cure in segments due to the chemical cure).
• Trim to the desired contour and adjust the bite to ensure against impacting occlusal forces.

DISCUSSION

With 2 years of use of TheraBase as an interim restorative material for replacing dentin and enamel, we cannot predict long-term resistance to fracture, wear, or erosion of the material when used as described here. However, in our early observations, we have seen no such material damage. In vitro laboratory experimentation and in vivo clinical studies would be useful to determine the capabilities of TheraBase interim restorations over time. However, in cases of primary teeth that have limited time before exfoliation (1 to 3 years), TheraBase could be a reliable, durable, and extremely easy-to-use temporization material (Figures 4 to 8). In addition, it features excellent radiopacity (Figure 9). This material also shows promise as a rapid stop-gap solution in permanent teeth requiring a quick and easy repair in office emergency scenarios or in any clinical circumstance when a delay is needed until more long-term treatment can be pursued (Figure 10). Examples are a temporary fill of an endodontic access opening or interim repair of a tooth with a sensitive caries lesion, with or without enamel hypoplasia/hypocalcification. Partially erupting permanent teeth exhibiting caries lesions can also be temporarily treated with TheraBase, such as the molar shown in Figure 11. When TheraBase was placed in that tooth one year prior, one-half of the crown was covered by the soft-tissue operculum, and short of an operulectomy, access was limited. Figures 12 and 13 show 8- and 10-month postoperative images of emergency repairs in patients. Figure 14 is a montage of 6 primary and permanent molars, all of which had been repaired with TheraBase 12 to 24 months post-op.

Figure 4. Four months after mesial-occlusal repair of a second primary molar in an 11-year-old.

Figure 5. Seven-month-old mesial-occlusal-distal TheraBase repair in a 12-year-old.

Figure 6. Eight months after Class II repair of 2 primary molars in an 11-year-old.

Figure 7. Eight-month-old “MOD” interim repair of a primary second molar in a 12-year-old.

Figure 8. Ten months after silver diammine fluoride caries attenuation and TheraBase repair in a 9-year-old.

Figure 9. Radiographic view showing material radiopacity of 3 primary molars (2 shown in Figure 6), plus the mandib- ular primary first molar, near exfoliation, 10 months postoperatively.

Figure 10. Six months after an “emergency visit,” TheraBase repair of a sensitive carious tooth was done in a 19-year-old.

Figure 11. A permanent second molar in a 13-year-old was partially erupted when interim repair was needed one year prior.

Figure 12. Interim emergency premolar repair, 8 months post-op, after a 16-year-old patient fractured a disto-occlusal resin-based composite (RBC) restoration.

Figure 13. Emergency TheraBase restoration 10 months post-op after a 19-year-old patient fractured a mesial-occlusal-distal RBC. Residual RBC is seen at the margin.

Figure 14. A montage of 6 permanent and primary molars that had been repaired with TheraBase 12 to 24 months post-op.

REFERENCES

1. Croll TP, Cavanaugh RR. Posterior resin-based composite restorations: a second opinion. J Esthet Restor Dent. 2002;14(5):303–12. doi:10.1111/j.1708-8240.2002.tb00526.x 

2. Cannon ML. A 21st-century material for all deep restorations. Inside Dentistry. 2022; 18(8):44–5. 

3. BISCO. TheraBase Base Safety Data Sheet. https://www.bisco.com/assets/1/22/TheraBase_Base_SDS_US_English.pdf

4. BISCO. TheraBase Catalyst Safety Data Sheet. https://www.bisco.com/assets/1/22/
TheraBase_Catalyst_SDS_US_English.pdf

5. Kuraray Dental. MDP Monomer. May 13, 2018. Accessed January 26, 2022. https://
kuraraydental.com/clearfil/key-technologies/mdp-monomer/

6. Lively T. What is MDP and why is it an MVP for bonding? Dental Products Report. 2021;55(11).  

7. Primus C, Gutmann JL, Tay FR, et al. Calcium silicate and calcium aluminate cements for dentistry reviewed. J Am Ceram Soc. 2021;105(3):1841–63. doi:10.1111/jace.18051

8. Christensen R. TRAC Research: Disinfection of tooth preparations—why and how? Clinicians Report. 2009;2(11):1-2.

9. Christensen R. Focus On: Tooth preparation disinfection. Dent Today. 2014;33(3):16. 

ABOUT THE AUTHORS

Dr. Croll is the clinic director of Cavity Busters Doylestown in Doylestown, Pa; an adjunct professor of pediatric dentistry at the Dental School at the University of Texas Health Science Center at San Antonio; and a clinical professor of pediatric dentistry at the Case Western Reserve School of Dental Medicine in Cleveland. He can be reached at willipus@comcast.net.

Dr. Gutmann is professor emeritus at the Texas A&M University College of Dentistry in Dallas and a distinguished adjunct professor in the Department of Cariology at Saveetha Dental College and Hospital in Chennai, India. He can be reached at jlg4570@aol.com.

Dr. Lawson is the director of the division of biomaterials and program director of the biomaterials residency program at the University of Alabama at Birmingham School of Dentistry. He can be reached at nlawson@uab.edu.

Disclosure: Dr. Lawson receives research and honoraria from BISCO, Kulzer, and other companies not mentioned in this article. Drs. Croll and Gutmann report no disclosures.

At age 14, I declared that I would be a dentist someday, but what I didn’t realize was how my work would allow me to impact people’s lives well beyond the dental chair. I never dreamed I would be able to quickly and effectively rehabilitate smiles using digital technology.

Admittedly, my happiest moments are when I get to both be creative and provide an exciting and easy experience for someone. Maybe this is why sharing what I do consistently on social media comes so easily. My enthusiasm to share what can be done using digital dentistry and the adrenaline rush I get from impressing the patient has always felt like a win-win scenario. 

However, if my 20-plus years of experience has taught me anything, it is that you cannot underestimate the value of digital planning, smile design, and effective workflows. This was never more evident than when I performed a combination of orthodontics and restorative bonding on my cousin, Jocelyn, who lives 2 provinces away, in only 9 months and 3 visits. Without the help of these key elements, we could not have performed this treatment with such incredible results.

Although I do many cases with a combination of orthodontic and restorative (porcelain or composite veneers), I chose to share this case because I want all doctors to realize that even the most basic digital workflows will help them to transform a patient’s smile much more simply than they can without them. Many doctors are hesitant to start using digital workflows because they think they are too difficult to learn or will ultimately not be any faster. I am here to suggest the opposite. 

CASE REPORT

Background

In July 2019, I was vacationing in Newfoundland, the most easterly province in Canada, where I grew up. For reference, my practice is in Saint John, New Brunswick, nearly 1,500 km (900 mi) away. Known for its remote living and rugged, beautiful coastline, I met up with my cousin, Jocelyn, who accompanied me on a hike on Change Islands, where our families are originally from. She was in the process of completing her master’s degree and wanted to apply for a more advanced position in her profession. But the problem was that she felt her smile was holding her back from being confident enough to pursue and achieve her goals.

As any rational dentist would, we stopped on the trail as I got her to lift her lips and cheeks and show me her teeth from every angle. Something in me just wanted her to know it was possible. I wanted to give her hope when she had not received much encouragement in the past. Newfoundland is a very large province but has less access to advanced services like smile reconstruction and specialized health care. 

I not only told her it could be done but that it would be “relatively easy” using the old “fake-it-til-you-make-it” mindset. I was so excited to help her!

The truth is, I knew I could do it in a minimally invasive way, but the challenges included the fact that my clinic was so far away and that she would require orthodontics first. The thing I didn’t realize was how important my digital planning and systems would be. I wanted a plan that would be minimally invasive and efficient travel-wise, so digital planning saved us time and potential mistakes. 

Clinical Exam

Jocelyn, a 44-year-old female, made her first visit to the clinic in January 2020. We performed diagnostic records, including a panoramic x-ray, a 3D iTero scan (Align Technology), a full complement of intra- and extraoral photos, and a clinical exam (Figures 1 to 3).

Figure 1. Preoperative portrait image.

Figure 2. Pre-op close-up smile.

Figure 3. Pre-op ortho panoramic x-ray.

Diagnosis

My examination and digital records found an overall deficiency in the upper arch tooth structure and arch form. In addition, there was a significant asymmetry on the right side due to a missing canine and a particularly small peg lateral. This left the smile asymmetric and slightly canted. Furthermore, when she spoke, the severe crowding on the lower arch was very noticeable

Clinical Observations  

Lower arch: There was normal to excessive tooth structure with severe crowding and a lingually displaced and severely chipped lower left central (it was also the most displaced due to the crowding).

Upper arch: There was narrow arch form, deficient in tooth structure (missing right canine and peg laterals, and the right lateral was smaller than the left).

Other notable findings included a Class I molar, normal attached gingiva, minimal tooth wear (except for the lower central), and a maxillary midline slightly to the right and canted (Figure 4).

Figure 4. STL intraoral images of the initial scan.

Treatment Plan

Overall, my goal was to align teeth and make restorative space for bonded restorations, which would be done after orthodontic correction using clear aligners. To provide harmony to the smile, I would need to make the upper arch bigger and replace the missing tooth structure while reducing crowding on the lower arch for an overall more aesthetic appearance.

Two options to correct crowding on the lower arch were presented to the patient. 

Option 1 was to do maximum interproximal reduction (IPR), where every tooth on the lower arch would give up approximately 0.25 mm of tooth structure on every side, as far back as the first molars. The con to this would be an extra trip to the clinic (along with added treatment time). 

Option 2 was to extract one lower incisor (ideally the most crowded and damaged).

Using the iTero’s Invisalign Outcome Simulator Pro and the Invisalign website (Align Technology), I was able to play out both scenarios and choose the best option for the case and the situation. Again, thanks to the digital help, I could quickly and efficiently, without harm to the patient, simulate different options. Due to the nature of the crowding and the midline issue, in addition to the fact that IPR would mean an extra 2 flights or a 21-hour drive, we chose to extract the lower left central tooth (Figure 3). 

As a GP who does both restorative and ortho, I felt confident to build up the peg laterals with bonded resin restorations and transform the upper right bicuspid into a canine. I just needed to make enough space around the lateral to allow for the material. Then the neighboring bicuspid (the second premolar) could take its place. 

Because I had done many cases with peg laterals and ortho, I knew my restorative for this would be more minimally invasive using composite over porcelain, although I do use porcelain in some cases. I also knew that we needed to expand the upper arch as much as possible before bonding and make space around the peg laterals before closing later with the bonded resin restorations.

I did consider moving the teeth on the upper right to make an implant space for the upper right canine, but again, knowing what I could do with bonding and how long implant placement would add to treatment time, this particular adult patient did not want this longer and more complicated treatment plan.

Treatment Timeline

The clear aligners used in this case were Invisalign (Align Technology), and delivery of the appliances occurred in late Feburary 2020 (which was quite fortunate given the unfortunate closure of the clinic just a few weeks later). Jocelyn’s lower left central incisor was removed on the delivery day, and vertical rectangular attachments were placed on neighboring teeth using Tetric EvoFlow Transparent (Ivoclar) to move the other crowded teeth into the space, closing it in just 3 months! She was instructed to change her trays every 3 days as we had performed Propel MOPS (micro osteo-perforations), and 75 upper and lower trays were provided. To note, when the trays were in place, the space was not nearly as noticeable because the plastic made the area look “blurry.” This was great because she was then not bothered by the temporary gap in her smile (Figure 5).

Figure 5. Before and after images of the ClinCheck treatment plan (Align Technology). The image on the left with pink attachments shows stage 1 (aligner 1) with attachments in place. The image on the right has green, square boxes that indicate spaces of 0.5 mm around the lateral that were created once expansion occured and that allowed for bonding material.

Jocelyn’s teeth finished active movement at the end of September 2020. Thanks to digital help, we were able to order her passive (non-active retention) aligners from the website to hold her teeth and stabilize movement for 6 weeks before final restorations. She began wearing her non-active aligners in October, and we performed the restorative procedure in mid-November, luckily just prior to the next shutdown due to COVID-19. This gave a total treatment time of just more than 9 months (Figures 6 and 7).

Figure 6a

Figure 6. (a) During week 1 (without align- ers in). (b) The patient, once home, sent a clinical photo using an iPhone for progress check-in.

Figure 7. Progress photos sent during the final week of active Invisalign treatment (September 2020).

She presented in November to remove the attachments and receive aesthetic restorative treatment. Because she had been sending digital images of the teeth monthly during her orthodontic movement, there was little surprise that we ended up with what we had digitally planned from the beginning (spaces around the upper right lateral and canine), allowing the bonding in this area to appear natural. Due to limitations on her work, I had only one day to finalize the smile design, remove the attachments, laser the gingival tissues to even the smile, perform direct resin restorations, and scan for final retainers.

After removing the attachments on both arches and taking more photos, I used the Epic diode laser (BIOLASE) first to modify the gingival contours of the tissues (this provided more symmetry and was required on the laterals only). Immediately following the laser (often, I would do this weeks in advance of the restorations), I added aesthetic composite restorations on all the upper teeth from premolar to premolar to make the smile as symmetric and color-matched as possible. 

Materials used included IPS Empress Direct (Ivoclar) A1 Dentin, B1 Enamel, B1 Tetric Evoflow (Ivoclar), and the Bioclear Matrix System to close the larger spaces on the upper lateral and canine. IPS Empress Direct material was then used on the surface to match, and A.S.A.P. All Surface Access Polishers (Clinician’s Choice) were used for the final polish.

Final photos were then taken, an iTero intraoral scan was performed, and Vivera retainers (Align Technology) were ordered. Again, due to the travel distance, the retainers were mailed to her. 

She was so blown away by her smile. We asked if she would do a testimonial video interview to help us show our followers and the public how easy the process was (Figures 8 and 9). Footage from this video is currently on our YouTube channel, called Peggy Bown Dentistry.

Figure 8. (a) Before and (b) after portrait of our patient smiling.

Figure 9a

Figure 9. Before and after (a) smile photos and (b) STL 3D intraoral scans.

CONCLUSION

There is really nothing quite like dentistry today (and that is not a pun for this publication). When we stop and think about what we can do, the time we can do it, and the highly predictable ways in which we do it, we should all be walking around with our own beaming smiles. 

It is so awesome to be a dentist with access to digital planning and aesthetic adhesive dentistry. I am grateful I get to create stunning smiles that can give my patients a new and better life, and it is extremely rewarding work, which I now share how to do in my digital and mentorship program called the Modern Dentist. It is cases like this that remind me how fortunate we are as dentists, especially when I think about what dentistry was like not so long ago.

ABOUT THE AUTHOR

Dr. Bown is a 2001 graduate of dentistry from Dalhousie University. In 2015, she opened a modern and fully digital clinic in Saint John, NB, Canada. Her passion is creating the ultimate patient experience while performing interdisciplinary treatment, including Invisalign. In 2016, Dr. Bown became Canada’s first Digital Smile Design Master and has taught doctors both nationally and internationally on the topics of digital workflows and social media/dental marketing. She hosts a weekly podcast called The Truth About Dentistry, covering a wide array of topics in general dentistry, and in 2021, she developed a mentorship program called the Modern Dentist. In includes one-on-one, live, and on-demand courses. Her passion for the patient experience stems from a childhood exposure to dentistry where patients were made to feel special, educated, and included in the treatment process. This is a very important part of her clinic culture and professional mission. She can be reached at peggy@smilesbybown.com, the website smilesbybown.com, or via her Instagram handle @drpeggybown. 

Disclosure: Dr. Bown reports no disclosures.  

Cosmetic dentistry is being sought out in record numbers, with experts saying the current market size of $29 billion could grow to nearly $60 billion before the end of the decade.¹ Prospective cosmetic patients are coming into my office younger and younger, fueled by social media and near-constant comparison to Hollywood smiles.² 

When considering restorative solutions for younger patients, clinicians must foremost be mindful of the long-term dental health of these patients. It’s imperative to consider the psychological effects of our treatment—or decision not to treat.² Feeling self-conscious about one’s appearance—especially during crucial stages of development—can influence psychological well-being. 

CASE REPORT

Featured in this case is a 15-year-old girl who presented near the end of her orthodontic treatment. Along with her mother, she came to me looking for an immediate solution to her “smile issue.”

As seen in her initial photographs (Figure 1), when we asked her for a big smile, she gave us a closed-lip smile. She’d trained herself to only smile with her lips closed.

Figure 1. When asked to smile, this young patient would only give a lips- pursed smile.

After a bit of coaxing, she gave us the smile in Figure 2. Her smile was very embarrassing for her. She had tooth size discrepancy, resulting in small teeth with gaps between them. Her mother explained she “wanted to have a smile like her friends.” The young woman’s lack of confidence in her smile was affecting her performance as a competitive cheerleader and made her feel inferior to her peers.

Figure 2. When coaxed, she finally revealed her teeth in a strained, open-lipped smile.

Patients such as this will often hear they’re too young for “permanent” treatment; they will have to wait until they reach 18 or 21 years of age, if not older, to receive their desired treatment.

With a very conservative approach to removing tooth structure, we can—and should—treat these patients. Their confidence and personality development relies on it.

Figure 3. Retracted view of dentition. Note engagers from clear aligner therapy were still in place.

Figure 3 shows the patient’s smile evaluation, displaying:

1. The short lower one-third of her face
2. Midline correct and occlusion, Class I
3. Very small teeth with very little showing
4. Multiple diastemas in the upper and lower teeth
5. Dark shade

The goal was to have a more “toothy” smile—close all the spacing and improve the color while keeping the patient’s natural tooth structure. 

Various treatment modalities were considered.  

1. Delay any treatment until the patient has reached maturity. As stated above, I believe waiting to address appearance issues such as this are detrimental to the patient.
2. Direct composite bonding to close the spaces. If these spaces were simply closed with direct composite bonding, the proportion of the teeth would be wrong, and we would end up with a different aesthetic problem: short, fat teeth. Attempting to add length by cantilevering direct composite would not likely be successful in the long term.
3. Indirect ceramic veneers of the maxillary teeth to close the spaces and add length. Gingival sculpting prior to veneer placement could add 1 to 2 mm of height to the teeth as well. Whitening of all other teeth would be included, as well as direct composite bonding to close the lower diastema.

Treatment 3 was ultimately selected. 

Gingival sculpting was done to lengthen the teeth 1 to 2 mm. The Gemini Laser (Ultradent Products) was used. Figure 4 shows the right side sculpted with the left side not yet completed. Already, the teeth appear more appropriately sized.  

Figure 4. Gingival sculpting completed on the right side. The left side shows pre-sculpting gingiva architecture.

Figure 5. Minimal preparation of the teeth was done with sharp edges and corners being rounded for idealized ceramic adaptation.

Preparation for the ceramics was ultraconservative. Figure 5 shows the sharp corners were rounded and smoothed with discs—no further enamel was removed. The case was impressed, and provisionals were made. 

The provisionals are the prototype for the final restorations, allowing a preview for the patient and clinician. In Figure 6, you’ll see occlusion and aesthetics were given a trial run. The patient wears the provisionals for a week or so, then returns to the office for evaluation.   

Figure 6. Provisional restoration prototype.

Figure 7. This photo was taken the day after the provi- sional prototype was placed. The joy and confidence the patient felt from her new smile was evident.

The day after prepping and placing the provisionals, our office received a text from the patient’s mother. The young woman was at a big cheerleading competition, and her mom took the photo in Figure 7. The text read, “Thank you, thank you, thank you!!! This is the first time I’ve seen her smile while she is cheerleading.”

Figure 8. Final restorations, adding length, improved shade, and smile “presence” (layered IPS e.max CAD restorations [Ivoclar] [Charles Moreno, Excel Studios]).

Figure 9. No more coaxing was necessary for this patient to smile. She radiates happiness with her smile now.

The veneers (layered IPS e.max CAD [Ivoclar]) were fabricated and placed. Her lower teeth were whitened using Opalescence Boost (Ultradent Products). The diastema between her lower central incisors was closed with direct composite bonding (Mosaic [Ultradent Products]) (Figure 8). Ceramics by Charles Moreno (Excel Studios) (Figure 9) completes  the postoperative smile.

CONCLUSION

Self-image is part of the foundation of a developing sense of self-worth and self-esteem. Young adults with a positive self-image can grow with greater confidence, resilience, and independence, which can help them navigate challenges and setbacks throughout life.

As dentists, we have the opportunity to help these patients’ psychological well-being while doing so in a way that also promotes the long-term well-being of their oral health.

REFERENCES

1. Market Research Reports Service. Global cosmetic dentistry market size, share and COVID-19 impact analysis, by product type (dental systems and equipment, dental implants, dental implants, dental bridges, dental veneers, dental crowns, orthodontic braces and inalys & onlays), by end user (dental hospitals and clincs, dental laboratories and others), by age group (children and adults) and regional forecasts, 2022-2028. Markets N Research. 2022. 

2. McMahon S. Selfie culture, young adults, and cosmetic dentistry: snapchat dysmorphia creates new aesthetic demands from teenagers and young adults. Dent Today. 2021;40(4): 52-57.

ABOUT THE AUTHOR

Dr. McMahon is a graduate of the University of Pittsburgh (Pitt) School of Dental Medicine. She maintains a private practice focused on cosmetic dentistry in Pittsburgh. Dr. McMahon is accredited by the American Academy of Cosmetic Dentistry (AACD) and is an invited Fellow of the prestigious American Society for Dental Aesthetics. She is a past clinical instructor in prosthodontics and operative dentistry at Pitt. Dr. McMahon frequently lectures across the United States on minimally invasive dentistry and conservative cosmetic dentistry for teenagers and young adults and has been annually voted by her peers as a top dentist in Pittsburgh for more than 20 years. She can be reached via email at drsusan@wowinsmile.com.

Disclosure: Dr. McMahon received an honorarium from Ultradent Products for writing this article.

Three-dimensional facial scanning began its evolution in the facial-recognition fields of government and the civil authority sector.^1-4 As dental professionals, we know the value of having the laboratory see the patient up close and personal. The current digital data capture of 3D facial scanning and artificial intelligence (AI) is the reality of how we can successfully treat our patients with a variety of applications. Three-dimensional facial scanning is an OBJ file that can now be used for diagnosis and treatment planning for any dental treatment involving replacing anterior and posterior teeth. By creating a “virtual patient,” or “dental avatar,” the clinician can transfer accurate data to the laboratory, allowing the software to simulate ideal treatment planning for replacing teeth.^5,6 Utilizing the central incisor position as a linear outline of the 6 anterior teeth, all data sets can be merged accurately. This will allow the accurate transfer of each data file as it is merged instantaneously through the AI that is inherent in this new software. Using this technology will surely increase the precision of many treatments involving the anterior teeth for facial and dental aesthetics, posterior teeth, the plane of occlusion, and morphology. This can be transferred very accurately (Figure 1). 

Figure 1. Merged files of a 3D facial scan, IOS, CBCT scan, and Artex articulator through exocad software.

METHODS AND TECHNIQUES

Patients were randomly selected that needed one of 3 types of treatments: complete denture, All-on-X implant therapy, or smile-makeover treatment. The digital data sets of information were taken at the consultation visit and seamlessly merged together through incisal edge position software and AI (Figure 2). First, an intraoral scan of maxillary and mandibular arches (IOS STL file) and a CBCT scan of the hard structures of both jaws (DICOM file) were made. Additional intraoral and extraoral photographs were also taken (JPG files). Secondly, the 3D facial scan (OBJ file) was made using RAYFace (Ray America). This machine has 6 dedicated cameras with a structured, built-in light. The 6 cameras extend more than 180° of the patient’s face. They align with a “big smile” view of the patient’s lips and teeth and get facially aligned in less than 5 seconds. All patients were asked to pull back their hair over their ears to allow the facial planes to be viewed. All headwear or obstructive facial jewelry must be removed to ensure accuracy. Multiple images can be taken in rapid succession, and the most natural-looking smile can be selected from all the images taken. After this capture process is successful, the AI of data merging begins. This software allows the importing of all data files to be seamlessly merged with one click. Each part of the patient’s data sets is imported into the RAYFace AI integrated software. Finally, the last step is the alignment of all x-, y-, and z-axes; facial planes; and all horizontal planes and accurate positioning of the data sets. Automatic plane and landmark detection technology (AI application) assist the user in reorienting the patient axis lines to achieve natural head position and detect the presence of canting on the occlusal plane or maxillary jaw discrepancies. All other facial planes, such as the ala-Tragus Line, Frankfort horizontal line, and occlusal plane lines, can also be viewed with just one click. This is performed by aligning the incisal edge position outline of the IOS scan with the CBCT scan. 

Figure 2. Three-dimensional facial scan showing all facial lines placed by artificial intelligence.

Once the accuracy and merging are confirmed, the alignment is checked for the ideal position. At this point, all the data sets are confirmed and merged. When this step is completed, the clinician can choose an ideal anterior smile design from a library of various shapes and sizes of anterior teeth to visualize the ideal smile position for the 3D facial scan. The next step is to download all the data sets into one complete file to be sent online or through the cloud server to the lab of your choice. This software also has a cloud-based data-sharing platform, enabling secure and efficient scan data management. At the laboratory, a variety of digital software can be used to create any treatment necessary for each patient. In these patient treatments, exocad software was utilized. The dentist, laboratory, and surgeon can now communicate to achieve the ideal tooth position with a dental avatar on their screens to discuss and plan all facial parameters and aesthetic needs, implants, surgical guides, and complete dentures for each patient.

CASE REPORTS

Case 1: Denture Protocol

Visit 1: Complete upper and lower preliminary impressions and a custom tray and final impression are made. All data sets of diagnosis are taken, a CBCT scan and a 3D facial scan are made, and the ideal tooth position in the frontal plane is designed (Figure 3).

Figure 3. Initial smile position of teeth from RAYface (Ray America) smile library.

Visit 2: At the second visit, the occlusal rim is fabricated using yellow wax. This is a paradigm shift because most laboratories use pink wax for this step. Yellow wax has a better contrast for the 3D facial scanner with all the black markings that will be made. The markings include facial midline, canine-to-canine lines from the inner canthus position, and the incisal edge of the occlusal rim. Once the parameters and Fox-plane analysis are completed and the OVD has been confirmed, a 3D facial scan is taken with the patient using all facial muscles to achieve a full, high smile (Figure 4). An IOS scan of the occlusal rim of the external surface and the intaglio surface is also made. Relining the occlusal rim with PVS material is highly recommended. A CBCT scan of the occlusal rim is made with fiducial markers on the occlusal rim to relate the CBCT scan to the occlusal rim.^7,8 All these data sets are instantly merged together with the software. The ideal facial and horizontal lines are viewed and aligned (Figure 5). All of the data sets are merged and packaged together and sent to the laboratory through the cloud-based data-sharing platform. The clinician, laboratory, and patient should also discuss and choose the best shade option for the patient. 

Figure 4. RAYFace scan of yellow wax rims with marked midline and canine lines.

Figure 5. Perfectly merged files of CBCT, IOS, intaglio surface of occlusal wax rim, and 3D facial scan through exocad with the horizontal lines, Frankfort lines, and occlusal planes.

Laboratory Steps: The laboratory imports all the data sets into exocad software (or any other planning software). The technicians design the tooth position, incisal edge, shape, width and length, alignment, buccal corridor extension, and occlusal plane (Figure 6). 

Figure 6. Final design of the denture with excocad software and a 3D facial scan.

This is also a paradigm shift. The current protocol for tooth selection is done by the clinician with various tooth-form guides and shapes utilizing pink wax. Usually, this resulted in many try-in and check-bite visits because this is a subjective choice based on vague ruler measurements and approximation. Many clinicians and laboratory technicians spend hours and days waxing the perfect set of denture teeth. This is a major step that will be eliminated if designs and records are taken digitally and enhanced virtually. Using the 3D facial scan and having the patient’s face with the occlusal rim in a digital format, the dentist and technician can better choose the ideal central incisor length, width, tooth form, and gingival zeniths. This allows easy manipulation of the design to achieve an ideal smile and tooth position in all 3D aspects. The laboratory technician can design this step, which can then be confirmed or edited by the clinician for the ideal position, length, and width through the email portal.

Figure 7. PMMA printed prototype at first try-in visit with bite registration, from the third actual visit.

Visit 3: The laboratory delivers a complete upper denture PMMA (printed) prototype to be evaluated for tissue fit, tooth position, occlusion relationship, the maxillary incisal edge, and shade (Figure 7). Seven complete denture patients were treated, and all 7 prototypes needed minor to no occlusal adjustments. Two of the 7 denture treatments needed more buccal corridor additions. During evaluation, all 7 denture treatments had perfect midline positions from upper to lower dentures and facial midline views. One of the 7 denture treatments needed a slight shade change. All 7 patients reported and evaluated their smiles as ideal or close to ideal for what they expected. The dentist prescribed the minor changes necessary to the technician, and all changes were made in the exocad design software and then translated to the final denture fabrication and insertion visit (Figure 8).

Figure 8. Final denture smile photo at the fourth visit.

Visit 4: All 7 final complete upper and lower dentures were processed (IvoBase Injection System [Ivoclar]) and delivered on the fourth visit. The clinician evaluated dentures for tissue fit, tooth position, occlusion relationship, the maxillary incisal edge, and shade. All 7 were acceptable from a clinical perspective and patient evaluation. A fit check of all tissue intaglio surfaces was performed. Occlusion contact and bilateral balanced occlusion were evaluated for ideal position and movement. Videos of the patients’ chewing cycles were made. Documentation and cataloging of all patient treatments was also made. Three- and 6-month recalls were scheduled to evaluate the fit and function of the treatments (Figure 9).

Figure 9. Final denture smile photo at the fourth visit.

Case 2: Smile Makeover

Visit 1: Complete upper and lower arches were scanned with an IOS (TRIOS [3Shape]) and CBCT scanner (RayAmerica). In addition, full-facial photos and videos were made to complete the aesthetic protocol of smile design. Files are imported into RAYFace software. A RAYFace 3D facial scan is captured. A simple smile design is made in the existing RAYface software and then exported to exocad software for ideal design (Figures 10 to 12).

Figure 10. Pretreatment smile photo of a patient.

Figure 11. Close-up smile before treatment.

Figure 12. Pre-preparation of merged files creating a dental avatar: 3D facial scan, IOS scan, CBCT scan, and smile design through exocad software.

Laboratory Steps: The ideal smile design is proposed using all the raw facial data merged through the incisal edge position and the IOS scans. The evaluation and quality control are up to the clinician to verify, change, or edit as needed. This will ensure ideal positions are viewed by the clinician and technician. Once the design is approved, the lab will send the clinician a printed model of the ideal design with a putty matrix or vacuum form to fabricate provisionals for the smile makeover (Figures 13 and 14). 

Figure 13. Final smile design through exocad of ideal shapes and lengths for a patient using a 3D facial scan to verify all proportions and facial lines.

Figure 14. Printed model of the final design.

Visit 2: Teeth are prepared for crowns or veneers with all ideal parameters: facial reduction, occlusion reduction, and color reduction for minimal prep cases. The matrix or vacuum form is filled with auto-polymerizing bis-acrylic material (Luxatemp [DMG]) with a specific shade chosen. It is allowed to set in 1 minute, and then it is removed, trimmed, and ready for insertion. The dentin shade photo is taken. A final impression is made for teeth prepared for the specific arch, and provisionals are luted, trimmed, and polished.

A final view and photographs are taken to evaluate the provisional smile makeover. Since the ideal smile design has been created with the 3D Facial scanner, this step should be very close to the ideal incisal edge, occlusion, position, labial extension, and buccal corridor alignment. The patient is scheduled for final adjustment 1 to 2 days after preparation to finalize aesthetics and specific patient input, speech, facial smile analysis, and lip support.

A final 3D Facial scan with RAYFace is made and sent to the lab for fabrication of final crowns or veneers (Figures 15 to 17).

Figure 15. Minimal preparation before applying the provisional matrix.

Figure 16. Provisional prototype of smile design through 3D facial scan and exocad software.

Figure 17. Facial photo with the provisional prototype trial smile.

Laboratory Steps: Final fabrication of crowns or veneers are done with a specific material and shade chosen.

Visit 3: The insertion and cementation of crowns is done, or veneers are placed (Figures 18 to 20). 

Figure 18. Three-dimensional facial scan to verify ideal provisionals for communication to the laboratory for final restorations.

Figure 19. Facial photo of final restorations, feldspathic veneers.

Figure 20. Before and after intraoral images of the smile 3 weeks after placement.

DISCUSSION

The 3D facial scanner RAYFace was used to capture a facial replica of each patient. The software was used to import all data sets for diagnostic evaluation of tooth position and analysis of facial planes using AI and software enhancements to create a “virtual patient” in the laboratory: a dental avatar. The accuracy seen at the delivery of the denture, smile makeover, and All-on-X treatments show promising results. More research with more clinicians using this software is necessary. This has become a useful daily diagnostic tool for replacing anterior and posterior teeth in our practice. The time and effort of the laboratory technician and dentist have dramatically decreased in all of these patient treatments. The educational model of our dental schools and educators must seek this technology to help our profession save time and money for our patients and simplify the procedures.

Additional uses for 3D facial scanners include, but are not limited to, full-arch provisional and final restorations, orthognathic planning treatments, orthodontics, and digital aligners, using the facial scan to complete the clinical check of the final movement. All of these existing digital programs and software can be used in conjunction with 3D facial scanner files to create the virtual patient called the “dental avatar.” This software includes an artificial intelligence component that can help both the clinician and laboratory technician in infinite ways and means to create the ideal tooth size, position, occlusion, and facial merging of data sets to enhance and expedite the final designs of many treatments in seconds. 

CONCLUSION

The paradigm shift for using 3D facial scanning to enhance and deliver accurate tooth positions and occlusion shows much promise for our profession. Continued research and documented patient treatments will reveal the true value of this technology in the next few years. This is likely to become as important as radiographs for many treatments as a diagnostic tool, similar to CBCT in the past 10 years. The educational model of our dental schools and educators must seek this technology to help our profession save time and money for our patients, dental students, and dental community. We are hopeful that the adoption of this technology will be swift and diligent. The NSU College of Dental Medicine in Davie, Fla—the first to take this bold step—is currently using 3D facial scanning for undergraduate education, and is the first prosthodontics advanced education program to adopt this technology. We hope others will follow and begin to change the protocols of the past.

REFERENCES

1. Breitbarth A, Schardt T, Kind C, et al. Measurement accuracy and dependence on external influences of the iPhone X TrueDepth sensor. Photonics Educ Meas Sci. 2019;11144:27-33. doi:10.1117/12.2530544

2. Thurzo A, Strunga M, Havlínová R, et al. Smartphone-based facial scanning as a viable tool for facially driven orthodontics? Sensors (Basel). 2022;22(20):7752. doi:10.3390/s22207752 

3. Bynum JH, Mirelez JA. 3D facial scanning: dual-arch fixed prostheses from diagnosis to delivery. Compend Contin Educ Dent. 2021;42(5):230–5.  

4. Li J, Chen Z, Decker AM, et al. Trueness and precision of economical smartphone-based virtual facebow records. J Prosthodont. 2022;31(1):22–9. doi:10.1111/jopr.13366

5. Lee JD, Nguyen O, Lin Y-C, et al. Facial scanners in dentistry: an overview. Prosthesis. 2022;4(4):664-678. doi:10.3390/prosthesis4040053

6. Karatas OH, Toy E. Three-dimensional imaging techniques: A literature review. Eur J Dent. 2014;8(1):132–40. doi:10.4103/1305-7456.126269 

7. Hong C, Choi K, Kachroo Y, et al. Evaluation of the 3dMDface system as a tool for soft tissue analysis. Orthod Craniofac Res. 2017;20 Suppl 1(Suppl 1):119–24. doi:10.1111/ocr.12178

8. Joda T, Brägger U, Gallucci G. Systematic literature review of digital three-dimensional superimposition techniques to create virtual dental patients. Int J Oral Maxillofac Implants. 2015;30(2):330–7. doi:10.11607/jomi.3852 

ABOUT THE AUTHOR

Dr. Vafiadis received his dental degree and prosthodontic specialty training at the New York University (NYU) College of Dentistry. He is currently an associate professor of prosthodontics and the director of the Full-Mouth Rehabilitation CE course at the NYU College of Dentistry. He is an adjunct professor of prosthodontics at Nova Southeastern University College of Dental Medicine and is a Fellow of the American Academy of Esthetic Dentistry. He lectures nationally and internationally for the NYU Continuing Education department. Dr. Vafiadis has been published and has lectured on various topics, such as aesthetics, implant designs, computer restorations, ceramic materials, and occlusion. He is the founder of the New York Smile Institute in New York City. He can be reached at drdean17@gmail.com.

Disclosure: Dr Vafiadis is a consultant and KOL for RayAMERICA, Ritter Implants, and Clinician’s Choice.

Virtual design and planning simplify treatment, especially when complex multi-phase care has been planned. Utilization of 3D printing allows the fabrication of provisional restorations during the same appointment as prep and design, yielding same-day aesthetic provisionals without needing to wait for fabrication by an outside lab. When provisional crowns are required to be present for months as other treatment is completed, such as the osseointegration of implants, the durability of the provisional material is important. If provisionals chip or fracture during that extended period of use, the patient gets frustrated, and the practitioner has to attempt to repair or remake them, increasing chair time and making treatment less efficient. The utilization of a high-strength aesthetic material also allows the patient to “test-drive” the aesthetics of the provisionals and permits modifications in the final restorations that satisfy the patient’s aesthetic desires. Novel 3D printing resins, such as OnX Tough (SprintRay), enable rapid fabrication of durable provisional restorations for such applications. A case is presented here illustrating complex treatment involving orthodontics to better position the teeth and placement of 3D printed long-term provisionals in preparation for implant placement. 

CASE REPORT

A 69-year-old female patient presented for consultation, expressing a desire to improve the aesthetics of her smile and replace her missing bilateral maxillary molars. Full-mouth radiographs were taken and evaluated (Figure 1). Decay was noted on the right second premolar (tooth No. 4) with no apparent pulpal involvement, and no apical pathology was noted radiographically. The right first premolar (tooth No. 5) had a PFM crown present with recurrent decay on the distal. Deep decay with pulpal involvement was noted on the right canine (tooth No. 6), with most of the coronal tooth structure affected. A midline diastema was noted between the central incisors, and facial flaring of the laterals and centrals was present. The left canine (tooth No. 11) was missing most of its coronal tooth structure, and pulpal involvement was noted on the radiograph with no apical pathology present. The left mandibular first molar (tooth No. 19) was missing most of the coronal tooth structure with no pulpal exposure noted.

Figure 1. Radiographs at the initial consultation demonstrating issues in the maxillary arch that the patient wished to address.

The patient returned to discuss treatment options and was presented with a detailed plan for the maxillary arch. This included endodontic treatment of the maxillary canines bilaterally, caries removal on tooth No. 4 with a resin core buildup, removal of the old crown on tooth No. 5, and crown preparations on both right premolars. Provisional splinted crowns would be placed on teeth Nos. 4 and 5 with orthodontic brackets embedded in the provisional crown resin. Brackets would be placed on the maxillary arch from second premolar to second premolar, and hyper-eruption of the canines would be performed bilaterally, along with uprighting of the centrals and laterals to close the diastema and better position the teeth aesthetically. Following orthodontic repositioning, the maxillary teeth would be prepared for crowns, and provisional crowns would be placed to provide improved aesthetics to the patient’s smile in preparation of implant placement in the molar area bilaterally. The patient was informed she would be in those provisional restorations for an extended period of time (6 or more months) as the implants integrated, at which time final restorations would be initiated for the entire arch. The patient agreed to the treatment plan after any questions she had were answered.

Figure 2. The defective crown on the first premolar and decay on the second premo- lar were removed with placement of a core buildup before crown preparations were refined on the premolars.

Figure 3. Splinted provisional crowns were printed with OnX resin bleach (SprintRay) with areas on the buccal for placement of orthodontic brackets to aid in the orthodontic treatment.

Endodontic treatment was initiated and completed on the canines. The decay was removed from tooth No. 4, a resin core buildup was completed using ParaCore dual-cure resin core material (COLTENE), and the tooth was prepared for a crown. The old PFM crown was removed from tooth No. 5, and the crown preparation was refined to remove any caries present (Figure 2). Teeth Nos. 4 and 5 were intraorally scanned with a CS 3700 scanner (DEXIS) and imported into exocad (exocad America). Splinted provisional crowns were designed with an area on the buccal of each to accept embedding an orthodontic bracket into the resin. The provisional crowns were then printed on a SprintRay Pro55 S printer (SprintRay) using OnX resin (SprintRay). The printed crowns were tried on the premolars intraorally and then cemented with Temp-Bond (Kerr Corporation) (Figure 3). Orthodontic brackets were luted into the provisional crowns with Transbond XT Light Cure Paste Adhesive (3M) and applied to the other teeth on the maxillary arch. An archwire was placed, connecting the brackets from second premolar to second premolar (Figures 4 and 5). 

Figure 4. Archwire was placed between the printed provisional crowns on the right premolars to the left premolars to initi- ate orthodontics to tip the centrals and laterals lingually and extrude the canines bilaterally.

Figure 5. Lateral views of the orthodontic brackets and archwire on the right and left at the initiation of orthodontics in the maxillary arch.

Figure 6. Facial view at the completion of orthodontics with closure of the diastema in the anterior maxilla and coronal positioning of the canines bilaterally.

Figure 7. Intraoral scan of the arches with a CS 3700 scanner (Carestream Dental) following crown preparation of the teeth in the maxillary arch, which was then imported into exocad.

Figure 8. View of the scanned arches in occlusion after crown preparation, demonstrating sufficient occlusal clearance for the planned restorations.

Figure 9. Virtual design of the planned maxillary provisional crowns.

The patient was seen on a regular basis to check and adjust the orthodontics as required, and at 5 months of treatment, orthodontics had been completed with extrusion of the canines bilaterally and uprighting of the laterals and centrals with the closure of the midline diastema (Figure 6). The orthodontic wire and brackets were removed from the teeth on the maxillary arch. The maxillary teeth were prepared for crowns and scanned with a CS 3700 scanner, and the file was imported into exocad (Figure 7). The occluded virtual arches were evaluated to confirm adequate occlusal clearance for the design of the provisional restorations (Figure 8). Virtual crowns were designed in the software with second-premolar-to-second-premolar splinting of the remaining teeth on the arch (teeth Nos. 4 to 13) (Figure 9). This was designed to lock the teeth in the established position that resulted from orthodontic treatment. The virtual provisional splinted crowns were laid out in DentalCAD 3.0 Galway (exocad) software to be printed on the SprintRay Pro55 S printer in OnX resin (Figure 10). The virtual provisional restoration was placed in the virtual build platform in preparation for 3D printing (Figure 11). After printing on the SprintRay Pro55 S printer with OnX resin, the restoration was removed from the unit with supports attached to the build platform (Figure 12). The supports were removed with a bur, and the areas were polished to complete the provisional restoration for intraoral insertion (Figures 13 and 14). 

Figure 10. Layout of the crowns to be printed, with a full-arch provisional restoration from second premolar to second premolar.

Figure 11. Virtual setup of the provisional to be printed on the build platform in the software.

Figure 12. After printing, the OnX Tough (SprintRay) resin provisional restoration was completed with supports on the build platform.

Figure 13. View of the buccal/facial surface of the full-arch OnX Tough printed provisional restoration.

Figure 14. View of the internal surface of the full-arch OnX Tough printed provisional restoration.

Figure 15. Trying in the splinted full-arch provisional restorations on the prepared teeth from second premolar to second premolar and in occlusion.

The splinted full-arch provisional crowns (teeth Nos. 4 to 13) were tried in to assess fit on the preparations (Figure 15). The aesthetics and occlusion were evaluated (Figures 16 and 17). The patient was shown a mirror to evaluate her improved smile, and she expressed that she was happy with the aesthetics. The provisionals were luted with Temp-Bond temporary cement. It was decided at a later appointment to optimize the aesthetics of the provisionals by changing to a lighter shade at the patient’s request and, as they would be worn for an extended period, to redo them in the stronger OnX Tough resin. Utilizing the same virtual design, slight modifications were made to the design in the software to improve the shapes of the teeth. The provisionals were reprinted in OnX Tough resin and then luted with Premier Implant Cement resin cement (Premier Dental) in clear shade. The OnX Tough resin yielded an acceptable aesthetic result for the patient (Figures 18 and 19). The patient would be in the provisional crowns for 6 or more months to allow placement of implants at the maxillary first molars bilaterally and to allow them to osseointegrate before being restored. During that period, the splinted provisional crowns would hold the maxillary teeth in a stable position and prevent anterior flaring.

Figure 16. Lateral views of the occluded maxillary provisional restorations.

Figure 17. Facial views of the provisional restorations utilizing OnX at the time of placement and 2 months later.

Figure 18. Restorations were remade in OnX Tough resin demonstrating better shade aesthetics to meet the patient’s desire for whiter teeth and more natural anatomy.

Figure 19. Lateral views of the patient’s smile demonstrating improved aesthetics with the provisional restorations using OnX Tough.

CONCLUSION

Complex dental treatment often involves treatment over an extended period of time while phases of care are being completed. This is especially true when implants will be included in treatment and time is needed for osseointegration before the final restorative phase can be initiated. When orthodontics will also be part of the treatment plan, and the remaining teeth in the arch will receive crowns upon completion of orthodontics, provisional restorations will be a key part of the treatment plan. Utilization of an aesthetic, strong provisional material allows the placement of provisionals that are aesthetic and will hold up well during the extended period of treatment time until final restorations can be placed. Digital planning, with intraoral scanning and virtual design of the provisional restoration, aids in this process, shortening the time that would be required compared to the traditional fabrication of provisionals at a lab. Digital 3D printing allows fabrication of those provisionals while the patient is in the chair and should be considered as a treatment option for the practitioner.

ABOUT THE AUTHORS

Dr. Ferguson has taught implant dentistry for the last 30 years and has lectured nationally and internationally. His lecture topics have included treatment planning, case selection, simple and complex surgical placement and restoration, advanced bone grafting and bone graft materials, use of CT and surgical guides, hygienic maintenance, and management of complications and failures. Dr. Ferguson has been instrumental in bringing low-cost 3D printing technology to dentistry and developing digital workflows for implant placement, restorative dentistry, and clear aligner orthodontic therapy. He has developed and implemented implant training programs and hands-on bone grafting courses, including at Implant Educators Academy—a 6-month implant live surgery continuum at the University of Florida. He maintains a private practice with his wife, Dr. Katherine Ferguson, in Davie, Fla, emphasizing digital dentistry and dental implants. He can be reached at drferguson@aol.com.

Dr. Kurtzman is in private general dental practice in Silver Spring, Md, a former assistant clinical professor at the University of Maryland in the department of restorative dentistry and endodontics, and a former American Academy of Implant Dentistry Implant MaxiCourse assistant program director at the Howard University College of Dentistry. He has lectured internationally on the topics of restorative dentistry, endodontics, implant surgery, prosthetics, removable and fixed prosthetics, and periodontics and has published more than 800 articles globally as well as several e-books and textbook chapters. Dr. Kurtzman has been honored to be included in Dentistry Today’s Leaders in CE listings annually since 2006. He can be reached at dr_kurtzman@maryland-implants.com.  

Disclosure: The authors report no disclosures.

Accurate recording of physical data is a critical task that dentists perform daily. The restorative workflow begins with preparing the area to be restored. This area, and the surrounding teeth and tissue, must be precisely captured. The definitive restorations are then designed and created. 

In the analog world, the data is captured with physical impressions, bite records, and face-bows. Models are fabricated from the impressions. Traditionally, the design phase involves manually waxing the desired final contours on mounted stone models, then manufacturing the final restorative product.

However, data can also be captured digitally with an intraoral scanner, resulting in a digital file. While digital technology captures data in a different way, it is still the same data used in the analog workflow.

Many software programs are available to create a computer-assisted design (CAD), such as CEREC (Dentsply Sirona), 3Shape, Simplant (Dentsply Sirona), and exocad. CAD programs were originally intended for use in the dental laboratory, with the expectation that the CAD design and manufacturing elements would be outsourced to the laboratory and not done in the dental office. Many of these programs are complex and have a steep learning curve to use them correctly.    

However, 53% of dentists now use intraoral scanners (IOS). IOS digitally capture 3D images of intraoral hard and soft tissue.¹ To accommodate the increasing number of dentists using IOS in their practices, the hardware, software, and workflows have evolved to give dentists a multitude of options to best adapt the technology to their practice needs.  

The design software can now be purchased in segments, so dentists can start with only the CAD portions that apply to their immediate needs. Live courses geared toward the dental team to learn this technology are also available. Once one segment has been mastered, additional modules can be added, allowing the dental team to increase its range of design and fabrication options. 

When the CAD portion of the workflow is done in the dental office, the dentist has more control of the functional and aesthetic outcomes. Dentists also appreciate the flexibility of designing and manufacturing on their own time schedules. Patients can view lifelike mock-ups of proposed treatments, which often increases their acceptance of definitive treatment plans. 

This article will outline in detail the steps necessary to digitally take a case from data collection through design using in-house CAD software. It will also demonstrate the steps necessary to perform a chairside evaluation of the digital mock-up and how to make any needed corrections to enhance the prototypes and final restorations.

CASE REPORT

A 27-year-old male patient was referred to the office by his orthodontist. Prior to surgery, he had been diagnosed with moderate obstructive sleep apnea and a bimaxillary retrusive malocclusion. The orthodontist aligned the arches with fixed appliances prior to orthognathic surgery. The patient presented postoperatively after a maxillary and mandibular surgical advancement, a LeFort 1 osteotomy on the maxilla, and a bilateral sagittal-split osteotomy on the mandible. 

Treatment goals established by the surgeon and orthodontist included enhancing both the facial aesthetics and improving the airway space (Figure 1).

Figure 1. Initial and final traced lateral cephalometric radiographs. Note the improved upper and lower jaw relationships relative to the cranial base.

The patient first presented to the office with orthodontic brackets in place. The orthodontist requested guidance to determine the ideal overbite-overjet relationship to accommodate future restorative materials and to obtain an ideal functional pathway. The patient desired to change the anterior tooth length, shape, and color. Photographs were taken (Figure 2). 

Figure 2. The overbite-overjet relationship was evaluated to ensure room for future restorative materials.

A direct composite mock-up was performed chairside to test the aesthetics and function of the proposed increased incisor length. Composite was added to the incisal edge of tooth No. 8. The patient was seated upright, and articulating paper was placed between the arches as he simulated his chewing pattern. There was less than 1 mm of clearance during chewing. The orthodontist was therefore instructed to tilt the incisal edge of the upper centrals 1 mm facially and intrude the lower incisors by 1 mm. The final goal after porcelain augmentation incisally would be to have 15% to 20% horizontal overlap and 1 mm of space between each arch in the chewing pattern. 

After debanding, the patient returned and a comprehensive exam, a full-mouth series of radiographs, a periodontal evaluation, diagnostic photos, and digital scans (iTero [Align Technology]) were completed. 

The patient’s medical history was noncontributory. His initial goal was to attain a “natural, beautiful appearance.” He did not like his existing short, square, yellow-speckled front teeth; misshapen lateral incisors; worn flat edges of the anterior teeth; and lack of buccal corridor fullness. He had no history of whitening. 

Analysis

Maximum lip dynamics occur when a person engages both the zygomatic major and the orbicularis oculi muscles.² During a full E smile, he displayed all gingival tissue on his maxillary teeth in the aesthetic zone³ (Figure 3). Dentofacial, the patient was high-risk with a poor prognosis for a successful aesthetic outcome because everything that needed to be restored was visible. He had a high gingival scallop and inflamed gingival tissue. He presented with a crooked smile that he reported having had his entire life. The right vermillion border was more apical than the left side when he smiled. His dental midline was concentric with his facial midline. His mandibular incisors were worn and in need of whitening and composite augmentation at the edges.

Figure 3. Preoperative view. Note the misshapen, short, square, yellow teeth with worn edges and the crooked smile.

Upon evaluation from a frontal perspective, 10 maxillary teeth were in the aesthetic zone. He liked the positioning of the second bicuspids and felt the fullness in that area was acceptable. The patient did not believe that including the second bicuspids in the restorative treatment plan would significantly improve the aesthetic outcome, so he elected to have only teeth Nos. 5 to 12 restored with minimally invasive veneer restorations.

In-House Digital Design 

Dental software design programs include options to use many different materials. A simplified workflow is outlined below that demonstrates designing provisional prototype restorations.

1. Load the software (exocad) on a PC and fill in the patient data.  

a. Choose one tooth (in this example, it was tooth No. 5) to be incorporated into the design. 

b. For a provisional where the tooth has not been prepped, choose “anatomic pontic.” The design program will add wax to the top of that tooth. 

c. The “waxup” option is for a tooth that has been prepped. When this option is selected, the design program will place wax over the prepped tooth. “Waxup” is intended to be used in the lab, and for our simplified purposes, we chose “anatomic pontic.” 

Select the material category, which is “3D print,” followed by adding any additional teeth to be incorporated in the design (in this case, teeth Nos. 5 to 12) (Figure 4). The teeth in the opposing arch will automatically appear as antagonists, facilitating functional and occlusion verification. 

Figure 4. The start of the design process.

2. Choose “digital impression scan” for the scan mode, then save the prescription and proceed to the design. 

3. The STL file is then exported from the scanner website in PLY format (which is colored to mimic the visuals of the arches) one arch at a time and oriented in occlusion.

4. The STL files are loaded. Rotating these files allows visualization of the overjet spacing available for restoration design (Figure 5). 

Figure 5. The STL files were rotated to evaluate the available restorative space.

5. Hover over the upper left, and slide the bars to change the translucency and allow the designer to show or hide an arch or tooth. This allows the removal of an arch or the selection of every tooth or every other tooth for designing purposes. Two modes, wizard and expert, can be used to design. Wizard mode gives a sequential series of prompts, while expert mode allows the operator to move between the prompts in whatever order desired. Hovering over an icon turns it orange, and text pops up explaining that prompt. Scan data orientation is adjusted and synced. 

6. Choose the tooth form from the program library (Figure 6). 

Figure 6. Tooth-library options.

a. To move the teeth as one unit, select “chain mode” and place the tooth models over the occlusal surfaces from the distal contact of tooth No. 5 to the distal contact of tooth No. 12 (Figure 7). 

Figure 7. Teeth were moved as one unit in “chain mode.”

b. Clicking on the green dots will change the color to red and lock that tooth in place. Future movement can occur in the chain without the red-dot teeth moving (Figure 8).

Figure 8. The teeth marked with the red dots could not be moved, while those marked in green could be moved.

c. Choose “tooth placement, single move” to allow movement of one tooth at a time, which does not allow for movement of the other teeth. To increase the fullness of the buccal corridor, the facial surfaces of the cuspids and bicuspids were intentionally designed with over-contoured facial and buccal surfaces (Figure 9). The proposed incisal edges were intentionally designed longer and with more closed and square incisal embrasures than the anticipated final, approved contours. 

Figure 9. Note the overcontouring of the facial surfaces to increase buccal corridor fullness.

7. The “tooth placement, advanced slide bar, anterior” function changes the edges from oval embrasures to flat embrasures (Figure 10). This gives the patient the ability to actually see how the smile would look if the veneers were made too long, too square, and/or too full. The dentist can then adjust contours, flatten the facials, and shorten and round the incisal edges during the provisional phase. This allows feedback from the patient until the patient approves of the smile design in the prototypes. Since the patient helps design the shape, form, and length, he or she takes more ownership of the aesthetic result. In this case, since the tooth forms were placed fuller and facially, a dehiscence was created at the neck, or cervical, of the central incisors. 

Figure 10. The “advanced changes” slide bar was used to flatten the incisal edges. Note the closed square incisal embrasures.

8. The “free-forming tool” was used to maintain the shape and form of the central incisors and move the necks. The design is rotated into a sagittal intraoral view. This tool allows the locking of the incisal edge and movement of individual tooth-form parts (ie, moving the cervical design inside of the tooth). This tool also allows editing of individual tooth parts, cusps, and ridges or the entire tooth (Figure 11). 

Figure 11. The sagittal intraoral view, free-forming locks the incisal edge and moves the neck of the prototype. Note that tooth No. 8 had been adjusted and No. 9 had not.

9. When the frontal perspective adjustments are complete, the occlusal is evaluated by looking at excess lingual material over the cingulum, which appears yellow (Figure 12). This must be removed for veneer design. The portions of the restoration that are in occlusion show in pink. These tooth parts are removed by using “free-forming anatomic tooth parts” and pulling tooth parts away from the natural-tooth lingual contours.   

Figure 12. The areas in pink were occlusal interferences to be removed. Note the yellow contour on the lingual that needed be removed for veneers.

10. The “free-forming free tool” is used for a final cleanup, allowing the designer to add or remove virtual wax. This tool acts like a virtual waxing knife. Wax is added by clicking and removed by hitting shift while clicking. Fine-tuning and shaping is accomplished by clicking “smooth/flatten” and holding shift to flatten or control for smoothing (Figure 13). The antagonist mandibular arch is brought into the scene, and the occlusion, overbite, and overjet are evaluated. Hovering over the upper left and sliding the bars will change the translucency and allow you to view the proposed design over the preoperative dentition (Figure 14).  

Figure 13. The “free-forming free tool” was used for final cleanup, as it allows the operator to add or remove virtual wax.

Figure 14. The proposed design was superimposed over the pre-op dentition by changing the translucency.

11. Export the final approved design as an STL file and send it to the 3D printer for fabrication of a maxillary model. Then fabricate a siltech provisional matrix (Virtual XD [Ivoclar]).

Preparation Appointment 

Local anesthetic was administered on the maxillary arch. The provisional matrix functioned as a preparation guide to ensure appropriate, but minimal, reduction. The guide was loaded with bis-acrylic composite (Luxatemp Ultra B1 [DMG America]) and seated over the maxillary arch.

The resulting prototypes were previewed. The length was shortened, and the middle thirds were flattened, then approved. Depth cut diamonds (Brasseler RWMIN .3/.5/.7 828.31.030 [Brasseler USA]) were placed across the facial gingival and middle third and established the facial reduction (Figure 15).

Figure 15. Depth cuts made into the approved prototypes ensured minimal reduction.

Next, 2 mm were removed from the previously approved incisal edge length, and since we lengthened the centrals 3.5 mm, no incisal reduction of the tooth preps was necessary.^4,5 A lingual chamfer design was chosen to enhance the resistance form of the preparation and to provide increased enamel surface for increased bond strength.⁶ The preparations were refined, and the gingiva was retracted. 

Records can be taken using a digital, analog, or hybrid workflow. A face-bow of the prepared teeth (Panadent), MIP bites (O-Bite [DMG America]), PVS impressions (Honigum [DMG America]), and photo documentation were taken and sent to the lab. Provisionals were fabricated with bis-acrylic composite (Luxatemp B1 [DMG America]) by loading the provisional matrix and then placing the matrix over the prepared teeth. The provisionals were luted with a combination of spot etching and bonding with Duo-Link veneer cement (BISCO) in the center of the prep and TempoCem ID (DMG America) at the periphery. In order to achieve high-strength, definitive, aesthetic restorations, IPS e.max Press (Ivoclar) Ingot HTBL 2 was selected as the material of choice.^7,8 

One week later, the patient returned for an evaluation of the provisionals’ shape, form, color, and function. He had initially asked for natural-looking veneers that were undetectable when compared to his existing mandibular teeth. This would have required color gradation and a combination of these A and B shades in the final porcelain. After wearing the provisionals in a B1 shade, he now wanted the new restorations to be slightly lighter and brighter than his existing lower teeth. He chose BL3 as the main body color. The outline forms of the contralateral teeth were contoured to be slightly different to allow the patient to view the different shapes and decide which he preferred. He chose symmetry, which is an exact duplication from left to right for his central incisors and accepted harmony, which was defined as a recurring theme, for his laterals and canines.

He gave written approval of the proposed shapes and shades for the definitive restorations. Final shade photos were taken in the same plane as the provisionals (Figure 16). Photo orientation and head position are critical to aesthetic digital design. The retracted, full-face photo is taken with the patient wearing Kois Facial Reference Glasses, which are designed to simplify capturing the correct head posture in photos (Figure 17). These additional records allow the ceramist flexibility in fabrication of the restorations in either the analog or the digital realm. 

Figure 16. Provisionals with shade tabs communicated the desired color and shape to the ceramist.

Figure 17. Kois Facial Reference Glasses captured the correct head position.

A digital scan of the approved provisionals is taken, sent to the lab to print, and is used as the master guide to design the porcelain restorations (Figure 18). 

Figure 18. A scan of the approved provisionals was sent to the lab to print.

Using photographs, the ceramist and dentist communicate virtually throughout the porcelain fabrication stages to ensure and verify that the aesthetic goals of the patient are met (Figures 19 and 20). 

Figure 19. The color and translucency of the IPS e.max restorations (Ivoclar) were verified virtually between the dentist and ceramist.

Figure 20. IPS e.max lithium disilicate restorations on the model verified shape characterization surface texture and incisal embrasures.

At the delivery appointment, the patient was anesthetized, the provisionals were removed, and the preparations were cleaned with pumice on a rubber cup (Figure 21).

Figure 21. Sectioning, then removal of provisionals.

The porcelain restorations were placed intraorally for aesthetic evaluation, (shape, color, and length), and written approval by the patient was obtained. The ceramics were HF-etched in the laboratory, and after try-in, the ceramics were cleaned by applying 37% phosphoric acid to the internal surface of the porcelain for 20 seconds, followed by rinsing with water. Next, the ceramics were primed by using silane (Bis-Silane, a 2-part silane coupling agent [BISCO]), allowing it to remain on the internal surface for one minute, followed by air drying. This step adds an organic molecule to the porcelain, which increases the adhesion by adding a chemical bond between the porcelain and resin cements. 

The tooth surfaces were then prepared for cementation, and the teeth were isolated (OptraGate [Ivoclar] and MicroEtcher [Zest Dental Solutions]).⁹ Evaluation of the remaining tooth structure revealed a thick ring of enamel. A selective-etch technique was used, applying etch only to the remaining enamel of the tooth structure and preventing the etching solution from touching the exposed dentin in the middle of the tooth. This facilitates greater mechanical retention of the veneers. A high-viscosity etch containing benzalkonium chloride (BAC) was placed on the enamel for 15 seconds, then rinsed with water (Select HV Etch [BISCO]) (Figure 22).¹⁰ 

Figure 22. A selective benzalkonium chloride etch technique avoided acid on the middle of the tooth where dentin was exposed in the preparation.

The high viscosity of the etchant minimizes slumping of the etch and allows the placement to be confined to the enamel. The BAC assists in inactivating the matrix metalloproteinases (MMPs). MMPs are believed to degrade the hybrid layer over time. An ethanol-based universal bonding agent (Adhese Universal [Ivoclar]) was applied to the teeth, scrubbed for 20 seconds, and air-dried for 10 seconds. Once the bonded surfaces were confirmed to be glossy and immobile, the preparations were light-cured for 10 seconds. The veneers were then luted into place with a light-cured resin cement (Variolink Esthetic LC [Ivoclar]).

After cement removal, the restorations were equilibrated. The patient closed in maximum intercuspal position until all posterior teeth displayed bilateral, simultaneous forces. The functional occlusion was evaluated with the patient sitting up in the chair and chewing on thick (22-µm) articulating paper, which simulates the chewing envelope, activating the closing muscles. A digital scan of the maxillary reconstruction was taken, Essix retainers were fabricated, and the patient was instructed to wear the Essix retainers indefinitely to maintain the achieved results (Figures 23 and 24).

Figure 23. Preoperative and postoperative close-up 1:1 view.

Figure 24. Pre- and post-op smile.

SUMMARY 

This case demonstrates a state-of-the-art, real-time digital workflow with the CAD done in the dental office. This process allows the prototype design to be linked to the definitive porcelain restorations while also allowing the dentist flexibility in designing and controlling the functional and aesthetic outcomes. The final outcome is predictable, and the process provides patient involvement in the aesthetic decision-making process, which improves patient satisfaction. While there is a learning curve in mastering the software, virtual and in-person educational opportunities are available. There has never been a better time to incorporate in-office CAD design. The advantages of improved restorative outcomes and patient satisfaction make it worth the effort to learn to use these tools.

ACKNOWLEDGMENTS

The author wishes to thank orthodontists Dr. Mark Steig and Dr. John Wachtel, surgeon Dr. Michael Golding, laboratory ceramist and artist Sandy Cook of Microdental NW, and Dr. Jean Martin for editing expertise. The concepts in this article are based on the teachings of Dr. Diana Tadros and the Kois Center.

REFERENCES

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ABOUT THE AUTHOR

Dr. Bassett practices comprehensive restorative and aesthetic dentistry in Scottsdale, Ariz. She is an Accredited Fellow of the American Academy of Cosmetic Dentistry and served as its president from 2015 to 2016. Dr. Bassett is a Kois clinical instructor, a member of the Academy of Fixed Prosthodontics, a Diplomate of the American Board of Aesthetic Dentistry, a Fellow in the AGD, an associate member of the American Academy of Esthetic Dentistry, and a member of the Catapult Education Speakers’ Bureau. She can be reached via email at drmouthy@aol.com or via the website drbassett.com.

Disclosure: Dr. Bassett reports no disclosures.