INTRODUCTION

It seems like cracked teeth are becoming a more and more prevalent finding in clinical practice. The ADA News and the New York Times recently published articles on this subject. One reason is people are living longer and are retaining their natural dentition. “Cracked teeth seem to be a result of repetitive stress injury, and so the longer teeth are in use, the more likely they will become cracked. This is a modern epidemic and something we have never before as a profession had to deal with,” said Rob Roda, past president of the American Association of Endodontists. “Cracked teeth are undergoing a time-dependent, load-related, progressive process that, without intervention, results in pain, infection, and splitting of the tooth requiring extraction.”

A cracked tooth can be defined as an incomplete fracture initiated from the crown and extending cervically and sometimes subgingivally, usually directed mesiodistally.¹ The depth and extent of the fracture are usually unknown and may progress to communicate with the pulp and/or periodontal ligament.

A cracked tooth diagnosis can be very perplexing because of the very vague nature of the presenting signs and symptoms. Do we treat, or do we extract? Studies show that the range of treatment for the cracked tooth can vary from conservative treatment modalities to extraction and replacement with implants. When a crack is suspected, guiding the patient to the proper treatment and then following up is paramount. The initial symptoms of a cracked tooth can often mimic those of pulpitis, necrosis, or apical periodontitis while there are clinically and radiographically no signs of caries. Most of the time, the involved tooth is minimally restored or not restored at all, making the diagnosis all the more difficult (Figure 1). The goal of this article is to help the practitioner navigate the complexities of diagnosing and treating the cracked tooth.

COMMON CRACK LOCATION

Mandibular first and second molars are the most susceptible to fracture, followed by the maxillary premolars. The crack is most often found on the mesial or distal marginal ridge or under an existing restoration.^2-4

DIAGNOSING THE CRACKED TOOTH

Understanding the extent of the crack is important as well. A craze line is a small crack that does not extend past the enamel. Teeth with craze lines will not cause any sensitivity to biting or temperature, and no treatment is necessary. Once a crack extends into the dentin, the patient can start to have temperature sensitivity and biting pain. As long as the crack does not extend into the root canal space, the crack can be managed by making a crown to establish complete cuspal protection. This treatment protocol is dependent on the patient’s symptoms.

If a tooth is minimally restored (or not restored at all) and has no caries yet presents with symptoms of pulpitis or necrosis, a cracked tooth should be suspected (Figures 1 and 2). These teeth can be retained if diagnosed and treated in a timely manner. The prognosis drops precipitously if the tooth has become necrotic. This would suggest that the crack has been there for a much longer period of time.⁵

Classic symptoms of a cracked tooth include sharp pain on biting (or release) and unexplained temperature sensitivity. Often, the patient has difficulty pinpointing the offending tooth, which makes reproducing the patient’s chief complaint all the more critical. One of the best ways to diagnose a cracked tooth is by testing each cusp of a suspected cracked tooth with a “tooth sleuth.”⁶ Cotton roll compression is another technique that can be employed.^2-4 Vitality testing is important as well. These tools will help to pinpoint the offending tooth.

Early diagnosis and detection are paramount in the management of the cracked tooth. With early detection, many teeth can be saved. Unfortunately, because the pain is intermittent, and due to the vague nature of the symptoms, there may be a delay in treatment. Many cracks are diagnosed when they have already extended deeply into the root structure, making the prognosis hopeless (Figures 2 and 3). These cracks also provide an avenue for bacteria to invade the pulp space, eventually leading to either an inflamed pulp (pulpitis) or an infected pulp (necrosis/apical periodontitis).^5,7 The cause of the sharp pain on biting is due to the movement of the fractured segments triggering fluid movement within the dentinal tubules. This fluid movement triggers nerve fibers located in and around the dentinal tubules.⁸

Figure 1 The patient in this case had been to multiple dentists over the past 2 years with a vague discomfort on the lower right side. Due to a lack of caries or restorations and the inability to reproduce the patient’s chief complaint, no treatment was rendered. A CBCT scan (Veraviewepocs 3D R100 [J. Morita]) revealed periapical radiolucency, as well as a narrow vertical defect, on the distal aspect of tooth No. 31. This was confirmed with clinical periodontal probing depths of 8 mm. This tooth also tested negative to vitality testing. A diagnosis of a cracked tooth with radicular extension was made, and extraction was recommended. All symptoms subsequently resolved. The extracted tooth revealed a crack running down the full extent of the buccal aspect of the mesial root. There was a second crack (not visualized) on the distal aspect corresponding with the distal bone loss.

Figure 2 The patient in this case presented with severe acute biting pain on the upper right. Tooth No. 4 was extremely tender to percussion and biting. There were no caries or restorations on tooth No. 4. You can see a crack line running mesial to distal on the occlusal table. A 7-mm periodontal pocket was probed on the mesial. A diagnosis of a cracked tooth with radicular extension was made. After the tooth was extracted, you can visualize the crack running from the mesial marginal ridge halfway down the root.

Figure 3 Tooth No. 18: The patient presented with severe pain to biting and continuous throbbing pain on the lower left. A diagnosis of pulp necrosis with symptomatic apical periodontitis was made. CBCT images revealed the cause being a cracked tooth extending in a mesiodistal direction and obliquely to communicate with the PDL on the lingual. The extent and direction of this fracture was not visualized on conventional radiography.

TREATMENT OF THE CRACKED TOOTH

There is a wide range of treatment options for the cracked tooth. Treatment will usually fall into 1 of 3 categories:

1. Crown

2. Root canal and crown

3. Extraction

The treatment depends on the status of the pulp and the depth of the crack. A surgical operating microscope is essential in determining the extent of the crack and the prognosis once the root canal is initiated.

If a cracked tooth is diagnosed with reversible pulpitis (no lingering sensitivity to biting or thermal stimulation), a temporary crown is advised for 6 to 8 weeks. If symptoms resolve, then proceed with a permanent crown. If symptoms don’t resolve, root canal therapy is indicated prior to permanent crown placement.^2-4

If a cracked tooth has a pulpal diagnosis of irreversible pulpitis (a crack that elicits spontaneous or lingering pain) or necrosis (infection) with or without a periapical lesion, then root canal therapy is indicated prior to crown placement (Table 1) (Figures 4 and 5). If root canal treatment is initiated and it’s discovered that the crack extends into the root, then extraction may be indicated.^5,9-13 A recent study showed very promising results when treating a cracked tooth, even when the crack extended into the radicular dentin.¹⁴ The technique employed used intra-orifice barriers placed apically to the apical extent of the crack in the radicular dentin. The goal was to prevent the ingress of bacteria and reinforce cervical dentin.¹⁴

Figure 4 The patient in this case presented with signs and symptoms of a cracked tooth (visualized clearly upon access of the tooth) and irreversible pulpitis associated with tooth No. 3. The patient was motivated to save the tooth with root canal therapy and a crown. The patient was completely asymptomatic after the first visit. The tooth was crowned one month after the root canal was completed. At the 2-year followup, the patient presented asymptomatic. The radiograph revealed no periapical pathology or marginal bony breakdown.

Figure 5 The patient in this case presented with acute biting pain on the lower left. A tooth sleuth revealed biting pain associated with the ML cusp of tooth No. 18. There was a lingering, painful response to vitality testing. Upon access, a crack line was noted running from the occlusal surface down to the level of the ML canal but not into the canal. A cracked tooth was diagnosed. The patient opted to have this tooth endodontically treated and then crowned. Upon the 3-year evaluation, the tooth was asymptomatic with no signs of periapical pathology or periodontal breakdown.

Figure 6 The patient in this case presented with a vague discomfort on the lower right. The gingiva adjacent to tooth No. 31 was inflamed and slightly swollen. The initial diagnosis was a periodontal abscess. Local curetting of the area temporarily relieved the patient’s pain. However, the patient returned with a similar discomfort after a short time. A CBCT scan was recommended and revealed a J-shaped radiolucency on the mesial root of tooth No. 31. A 10-mm periodontal pocket was probed on the mesiobuccal aspect of tooth No. 31. A diagnosis of vertical root fracture (VRF) was made, and extraction was recommended. After the tooth was extracted, a fracture was not only noted on the mesiobuccal, as expected, but surprisingly also along the distal root.

CRACKED TOOTH VS VERTICAL ROOT FRACTURE

A cracked tooth shouldn’t be confused with a vertical root fracture (VRF). VRFs are mostly found in previously endodontically treated teeth. These fractures are initiated at the apical end and progress coronally (Figure 6). They can also be found mid-root adjacent to the terminus of a post. On the other hand, cracked teeth are found mostly in teeth that have not had root canal treatment, and the crack is initiated in the crown and spreads apically toward the root (Figure 7). Cracked teeth can sometimes occur on endodontically treated teeth that have not been properly restored with cuspal coverage. Cracked teeth are often directed in a mesiodistal direction (Figure 8), while VRFs are mostly directed in a buccolingual direction within the root. The classic J-shaped or halo-shaped apical radiolucency, as well as the deep, narrow “isolated” periodontal pocket, is classically associated with VRFs (Figure 6). In contrast, classic symptoms of biting pain and unexplained temperature sensitivity are associated with cracked teeth.^15-18 While cracked teeth are amenable to a range of treatments, VRFs usually have a hopeless prognosis and require extraction and replacement with an implant. If the offending tooth is multi-rooted, it may be possible to resect the root with the VRF and retain the tooth with the remaining roots (Figure 9). Because the pain associated with VRFs may be fleeting and intermittent, the patient often doesn’t seek treatment until significant bone has been lost around the tooth.

Figure 7 The patient in this case presented with extreme pain on the entire right side of his face, extending into his ear. The patient reported on and off biting pain and temperature sensitivity over the prior 2 months. The pain had recently became unbearable. A clinical exam revealed that tooth No. 31 had pain on biting as well as a 7-mm probing depth on the distal. There was no response to vitality testing. A cracked tooth with radicular extension was diagnosed, and the tooth was planned for extraction. The extracted tooth revealed a crack running from the distal marginal ridge deep into the root structure.

Figure 8 The patient in this case presented with a chief complaint of on and off biting discomfort on the lower left. Tooth No. 19 was very sensitive to percussion and cotton roll compression. The cold test was inconclusive. A CBCT scan revealed PDL widening at the apex of the mesial and distal roots. Tooth No. 19 was planned for “exploratory” root canal therapy and a crown. After the amalgam was removed, a crack (cracked tooth) was seen running from the mesial to the distal. Once access was made into the pulp chamber, the full extent of the crack could be visualized running on both the mesial and distal aspects of the crown but not down to the pulpal floor. The patient returned for the second visit, reporting that all symptoms had subsided. The root canal was completed, and the patient was referred back to her dentist for the crown. The patient returned for the 10-month re-evaluation with a core buildup and permanent crown (no post). The tooth was completely asymptomatic, and the radiograph revealed no signs of periapical pathology or periodontal breakdown.

Figure 9 The patient in this case presented with a previously endodontically treated tooth No. 3. The chief complaint included a dull discomfort around the apical region of tooth No. 3. Radiograph examination revealed a periapical breakdown around the apex of No. 3. The J-shaped radiolucency around the MB root was strongly indicative of a VRF. The patient was very motivated to save this tooth, and a root resection was planned. Upon flap reflection and removal of granulation tissue, a VRF was clearly visualized. The MB root was resected.

ETIOLOGY OF THE CRACKED TOOTH

Cracked teeth are the result of repetitive stress to the dentition. They can also be the result of sudden stress on a vulnerable tooth. Repetitive stress would result from parafunctional habits such as bruxism and clenching, whereas a sudden stress injury could be the result of biting on ice, nuts, hard candy, etc.

CRACKS WITH AGE

Older patients have a more brittle dentin structure, and as such, their teeth are more prone to fracture. Rarely do we see classic cracked tooth symptoms in children or adolescents. One study found that the dentin is 50% weaker in those above 55 years old in comparison to those younger than 35 years old.¹⁹ It seems that the fatigue resistance of human dentin decreases with age.²⁰

PREVENTING CRACKS

One of the best ways to prevent cracking a tooth is to have the patient wear a nightguard if clenching or grinding is a habit.

A patient with a history of a cracked tooth should be evaluated for full-coverage restorations on teeth vulnerable to fracture in the future. It is very common to see a patient have a tooth removed due to a crack, only to return a short time later with a crack on another tooth because the edentulous space was never restored. The lack of a restoration after the loss of a tooth puts more stress on the remaining teeth, thus leading to greater vulnerability for fractures on the remaining teeth.

CONCLUSION

Diagnosing and treating the cracked tooth can be a complex endeavor. Many factors contribute to the proper diagnosis and treatment of the cracked tooth. With a better understanding of cracked teeth, more of these teeth can be saved than previously thought.

A chart outlining a few classic studies associated with cracked teeth and vertical root fractures is available here.

ACKNOWLEGEMENTS

The author wishes to thank Dr. Charles Solomon and Dr. Leslie Elfenbein for their valuable input.

REFERENCES

1. Rivera EM, Walton RE. Cracking the cracked tooth code: detection and treatment of various longitudinal tooth fractures. In: Colleagues for Excellence. Chicago: American Association of Endodontists; 2008

2. Cameron CE. The cracked tooth syndrome: additional findings. J Am Dent Assoc. 1976;93:971–5. doi:10.14219/jada.archive

3. Krell KV, Rivera EM. A six year evaluation of cracked teeth diagnosed with reversible pulpitis: treatment and prognosis. J Endod. 2007;33(12):1405–7. doi:10.1016/j.joen.2007.08.015

4. Kahler W. The cracked tooth conundrum: terminology, classification, diagnosis, and management. Am J Dent. 2008;21(5):275–82.

5. Berman LH, Kuttler S. Fracture necrosis: diagnosis, prognosis assessment, and treatment recommendations. J Endod. 2010;36(3):442–6. doi:10.1016/j.joen.2009.12.018

6. Türp JC, Gobetti JP. The cracked tooth syndrome: an elusive diagnosis. J Am Dent Assoc. 1996;127(10):1502–7. doi:10.14219/jada.archive.1996.0060

7. Ricucci D, Siqueira JF Jr, Loghin S, Berman LH. The cracked tooth: histopathologic and histobacteriologic aspects. J Endod. 2015;41(3):343–52. doi:10.1016/j.joen.2014.09.021

8. Brannstrom M. The hydrodynamic theory of dentinal pain: sensation in preparations, caries, and the dentinal crack syndrome. J Endod. 1986;12(10):453–7. doi:10.1016/S0099-2399(86)80198-4

9. Kang SH, Kim BS, Kim Y. Cracked Teeth: Distribution, Characteristics, and Survival after Root Canal Treatment. J Endod. 2016;42(4):557–62. doi:10.1016/j.joen.2016.01.014

10. Rivera EM, Walton RE. Longitudinal fractures. In: Torabinejad M, Walton RE, eds. Principles and Practice of Endodontics, 4th ed. Philadelphia: Saunders; 2009: 108–28.

11. Tan L, Chen NN, Poon CY, et al. Survival of root filled cracked teeth in a tertiary institution. Int Endod J. 2006;39(11):886–9. doi:10.1111/j.1365-2591.2006.01165.x

12. Sim IG, Lim TS, Krishnaswamy G, et al. Decision making for retention of endodontically treated posterior cracked teeth: a 5-year follow-up study. J Endod. 2016;42(2):225–9. doi:10.1016/j.joen.2015.11.011

13. Krell KV, Caplan DJ. 12-month success of cracked teeth treated with orthograde root canal treatment. J Endod. 2018;44(4):543-548. doi:10.1016/j.joen.2017.12.025

14. Davis MC, Shariff SS. Success and survival of endodontically treated cracked teeth with radicular extensions: a 2- to 4-year prospective cohort. J Endod. 2019;45(7):848-855. doi:10.1016/j.joen.2019.03.015

15. Tsesis I, Rosen E, Tamse A, et al. Diagnosis of vertical root fractures in endodontically treated teeth based on clinical and radiographic indices: a systematic review. J Endod. 2010;36(9):1455–8. doi:10.1016/j.joen.2010.05.003

16. Fuss Z, Lustig J, Tamse A. Prevalence of vertical root fractures in extracted endodontically treated teeth. Int Endod J. 1999;32(4):283–6. doi:10.1046/j.1365-2591.1999.00208.x

17. PradeepKumar AR, Shemesh H, Jothilatha S, et al. Diagnosis of vertical root fractures in restored endodontically treated teeth: a time-dependent retrospective cohort study. J Endod. 2016;42(8):1175–80. doi:10.1016/j.joen.2016.04.012

18. Tamse A, Fuss Z, Lustig J, et al. An evaluation of endodontically treated vertically fractured teeth. J Endod. 1999;25(7):506–8. doi:10.1016/S0099-2399(99)80292-1

19. Yan W, Montoya C, Øilo M, et al. Reduction in fracture resistance of the root with aging. J Endod. 2017;43(9):1494-1498. doi:10.1016/j.joen.2017.04.020

20. Seo DG, Yi YA, Shin SJ, et al. Analysis of factors associated with cracked teeth. J Endod. 2012;38(3):288–92. doi:10.1016/j.joen.2011.11.017

ABOUT THE AUTHOR

Dr. Stern is a Diplomate of the American Board of Endodontics. He is the director of endodontics at the Touro College of Dental Medicine and lectures frequently on the subject of clinical endodontics. He has lectured at many local county dental societies, the New Jersey Dental Association Annual Session in May 2019, and the Greater New York Dental Meeting in 2020. He maintains a private practice, Clifton Endodontics, in Clifton, NJ. He can be reached at jstern5819@gmail.com.

Disclosure: Dr. Stern reports no disclosures.

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CASE REPORT
Diagnosis and Treatment Planning
A 32-year-old male patient presented with an uncomfortable bite, wear of the maxillary anterior dentition, and wear on the mandibular canines. The patient had 2 options for selection of the treatment:
First, he could have opted to restore the lengths of the maxillary anterior teeth and the mandibular canines with veneers. This selection would have solved the problem of anterior esthetics, but it would not have addressed the long-term health and welfare of the complete mastication/chewing system. Because of the avoidance patterns, set up by the centric occlusion (CO) and centrically-related occlusion (CO/CR) discrepancy, the veneers would have been at high risk of fracture or delimitation, and severe wear on the opposing incisors due to off-axis loading.
The second option was to treat the entire system by following 3 principles:

1. Stabilize the joint in harmony with maximum intercuspal position (MIP) to eliminate the CO/CR discrepancy.
2. Recreate the sharp, unworn form to the teeth with intraoral coronaplasty procedures (subtractive and additive) in order to guard the chewing system from overloads.
3. Reinstate the form of the anterior teeth with veneers to re-establish the proprioceptive anterior guidance.

The patient selected the comprehensive approach for long-term health and appearance. The treatment plan in this case was to first stabilize the temporomandibular joint (TMJ) by the use of a maxillary anterior guided orthotic (MAGO). The confirmation of joint stability was to be determined by the use of periodic open bite centric records and adjustments to the MAGO until a stable joint position could be demonstrated on the axis position indicator (API) instrument (Panadent Corp).
After achieving a stable position of the joint, an axis recording would be taken to locate the hinge axis to determine the condylar angle and the extent of the Bennett movement. This information, along with new stone models, would be transferred to the articulator (Panadent Corp). These models, representing the patient in a stable condylar position (SCP), would then be used to perform an external coronaplasty and create a wax-up of the desired final results. The dental laboratory could also use the wax-up to fabricate a mold for the practitioner to construct temporary crowns, or use it as a guide in replacing tooth form with the composite materials. In turn, the provisional restorations would be evaluated and used to obtain approval from the patient for the appearance and function of the final restorations. The desired end result would be a stable, esthetic, comfortable, long lasting dentition.

Clinical and Laboratory Procedures
The patient was treated with splint therapy, using a MAGO appliance on the maxillary arch. The orthotic was placed and adjusted until the TMJs assumed their most superior/anterior medial stable position in the fossa. The appliance also allowed the joints and muscles to heal from any inflammation caused by neuromuscular disharmony, due to tooth interferences during movement and closure. The MAGO appliance also programs the central nervous system for verticalized closure and gives a stable healthy position from which to diagnose and treat the patient.

Figure 1. Initial anterior contacts and incisive/surtrusive pathways. Anterior contacts only for first 24 to 72 hours.	Figure 2. Posterior contacts and canine guidance additions with acrylic resin.
Figure 3. Left canine guidance. Note the clearance of 2 to 3 mm between the appliance and the mandibular posterior teeth on the nonchewing side and 1 to 2 mm of clearance on the chewing side.	Figure 4. The incisive test position. There is clearance of 2 to 3 mm in the posterior region.

After checking and adjusting the appliance to fit the teeth accurately, the next procedure was to create an even contact on the anterior acrylic area of the appliance between the 2 mandibular central incisors and the mesial aspect of the incisal edges of the 2 mandibular lateral incisors. No CR contact of the mandibular canines was permitted in order to avoid any tendency of the appliance to force either condyle out of the fossa. An 8-µm Mylar ribbon was used to ensure that the 4 contacts were equal in intensity (Figure 1). The posterior area of the appliance was left at least 2.0 mm out of contact.
The patient wore the orthotic for 2 days (24 hours per day, except for brushing and flossing). On the third day (Figure 2), acrylic was added to the posterior area to create contacts between the mandibular posterior teeth (one mark per centric cusp) and the appliance. Canine guidance (Figure 2) was also added by processing acrylic to the MAGO to ensure that no posterior contacts were present on the appliance in excursive movements of the mandible (Figures 3 and 4). Again, the canine area of the appliance was left slightly out of contact with the opposing mandibular canine. Any interfering contacts in the incisive/surtrusion (upward) and right and left medial/surtrusion pathways were removed (Figure 5). Once a week, for 6 weeks, the appliance was “challenged” with the use of several 0.003 tin foil shims (Buffalo Dental) placed on the anterior area of the appliance (Figure 6). The anterior metal shims separated the mandibular posterior teeth from the appliance (Figure 6), recreating a Class III lever. The shims were removed, one at a time, marking the posterior area with 12-µm thick Mylar articulating paper (such as Accufilm II [Parkell]), until a contact point was observed. The initial premature occlusal contacts were adjusted, ie, removed, using fine carbide burs and Cratex wheels. The process of removing the shims—one at a time—was repeated until even contacts were developed on the posterior and anterior teeth. During the last 3 weeks, the condyles were determined to be stable in position, by utilizing the API (Figure 7).

Figure 5. The completed maxillary anterior guided orthosis (MAGO) orthotic after adjustments showing incisive/surtrusive and canine guidance medial surtrusive pathways and cuspal contacts.	Figure 6. Size 0.003 tin foil shims (Buffalo Dental) placed on the MAGO.

Figure 7. The axis position indicator instrumentation.

Figure 11. Location of the hinge-axis. Reference pins are set at the hinge axis for a hinge axis transfer to the articulator.

According to the principles of Bioesthetic Dentistry, the MAGO created an orthopedically stable condylar position,¹ with the dentition having equal intensity contacts in closure, an anterior guidance that relegated incisive/surtrusive movement to the central incisors and excursive right and left medial/surtrusion movements to the canines, without any posterior CR contacts away from centric closure.
After the joint stabilized, the Panadent axis path recorder was used to locate the hinge axis and to measure the condylar angle and Bennett movements (Figures 8 to 14). A new stone model of the maxillary arch was fabricated and transferred to the Panadent articulator, utilizing a Panadent hinge-bow and maxillary mounting stand (Figure 15). This procedure aligned the patient’s axis of rotation with the hinge of the articulator.

A new mandibular model was then mounted, using a new open bite centric-related registration (Figure 16). The condylar angle was measured, using the condylar tracing and a Panadent protractor, then set on the articulator, along with the Bennett movement (by attaching the appropriate Panadent Bennett analogs) (Figures 8 and 14). With this information, all the necessary data to arrive at a final occlusal diagnosis was available. These models were used to plan the final coronaplasty.

EXTRAORAL CORONAPLASTY: CORONAPLASTY CONSIDERATIONS
Prior to proceeding with the occlusal treatment plan on the axis-mounted SCP models, the clinician must be aware that there are times when subtractive coronaplasty procedures alone fail to ideally restore anterior guidance or natural tooth form. In these cases, restorative procedures, performed by a restorative dentist, may be required to complete the case. During that process, the clinician must continually consider these questions:

1. What are the likely consequences of each option?
2. Which of the consequences can the clinician and the patient accept?

By performing the coronaplasty on the CR mounted models, the practitioner can become truly familiar with the case and help to guide patients through their choices. Before touching the model teeth, the clinician should visualize the envelope of functional motion as a 3-x-3-mm horizontal rhomboid-shaped figure, with the bisection of lines representing the test positions (Figures 17 and 18) at which the clinician will evaluate the clearance of the posterior teeth when the mandible is at that position: (1) incisive test position, (2) left lateral test position, (3) right lateral test position, and (4) CR test position—to observe impediments to closure and function and the deficiency of anterior coupling and guidance (Figure 17). These positions also represent the points of adjustments (adjustment positions) to the teeth at CR (4), incisive adjustment position and pathway (5), right and left lateral adjustment positions border pathways (6 and 7), and the adjustments at the intermediate pathways (8 and 9) (Figure 18). Following the evaluation of the CR discrepancy at test position 4, the actual adjustments to the posterior teeth begin at the first CR contact, in order to harmonize the intercuspal position, with the CR position of the TMJs. Certain protocols or rules are adhered to during the development of the CR contacts.

Figure 15. Axis mounted maxillary cast.	Figure 16. With an open-bite centric relation record, the models are mounted in stable centric on the hinge axis. Final diagnosis and treatment plan can now be established.

After determining the MIP stop point at the adjustment position 4, subsequent additive (addition of wax) and subtractive procedures are performed on the incisors and canines (positions 5 to 9) to finalize the incisive/surtrusion, right and left canine medial/surtrusion guidance, and intermediate pathways, and the anterior guidance, along with any special considerations.
The goal of a coronaplasty is to create the form of the teeth and a proprioceptive anterior guidance to permit incisive and eccentric functional movements of the teeth within this small space, without neuromuscular disharmony. When the teeth do contact (only in swallowing),² final closure position should be with equal intensity. There should be at least one small point of contact on each cusp tip where the convexity of the cusp tip touches the opposing convexity of the marginal ridge. At this point of closure, the TMJs are guided back into the CR position, thereby in harmony with the contact of the teeth (MIP).
In evaluating the clearance of the posterior teeth at the extent of border movements (test positions 1 to 4), the mandibular model is placed first in the incisive test position with the incisal edges end-to-end (test position 1) (Figure 19). At this position, the posterior teeth should have a clearance of ideally 3 mm at the second molars. In incisive/surtrusive guidance, it is important to see that the contacts of the incisal edges are simultaneous for both maxillary central incisors, and that the maxillary and mandibular midlines are lined up. If there is inadequate space, 2 choices are available: (1) reduce the posterior teeth, or (2) add to the length of the incisors to create more vertical overlap. On the models, this can be accomplished by adding wax (additive coronaplasty) to the incisal edges.
To evaluate the adequacy of the lengths of the canines and their effect on the posterior clearance in both sides (chewing and nonchewing), place the tip of the mandibular canine against the tip of the maxillary canine at test position 2 (left lateral) and again at test position 3 (right lateral). There should be 2 mm of clearance on the chewing side and 3 mm on the nonchewing side at the second molars (Figure 20). Again, the options here are to reduce the height of the posterior teeth or increase the length of the canines. Remember, it is not enough to create just the minimal “clearance” of the posterior teeth. Without adequate space, the posterior teeth can still contact during flexure of the mandible when chewing a hard bolus of food. These contacts become interferences to smooth function.
Do not sacrifice natural tooth length of the posterior teeth before first considering the lengths of the canines and incisors. Increasing their lengths will create greater posterior separation. However, the lengths of the anterior teeth must be evaluated in consideration of the esthetic appearance of the smile and the face. The length of the maxillary canines and central incisors should be evaluated together, and their incisal edges should be level with the horizontal plane.

Figure 19. Posterior interferences in incisive/surtrusive guidance.	Figure 20. Inadequate right canine medial/surtrusion guidance results in nonchewing side interferences on the second molars and chewing side interferences on the first bicuspid.

Figure 21. Anterior open bite due to centric interferences to closure at the second molars.

Preserving and recreating natural biologic form as advocated in Bioesthetic coronaplasty always begins with developing the CR contacts first before developing the additive procedures. At test position 4 (CR), with the articulator locked, the space between the anterior teeth is evaluated as to how much the posterior teeth would have to be reduced in order to get the anterior teeth to couple (Figure 21). The ratio between the second molar and anterior teeth is approximately 1:2.5. In other words, to close an opening of 2.5 mm between the anterior teeth CR contacts, a reduction of approximately 0.5 mm from the maxillary second molar and 0.5 mm from the mandibular second molar (a total of 1.0 mm) is required. If they are, in fact, the primary causes of the anterior CR open bite, fewer adjustments on the first molars and premolars would be required. If the anterior open bite exceeds 2 mm, too much tooth structure would have to be removed from the second molars. In that case, the option of additive restorative considerations would have to be made. With more excessive anterior open bites, orthodontic or surgical intervention may be necessary.

DISCUSSION
Adjustment Considerations for Centric Relation Tooth Contacts
At test position 4, where the actual tooth adjustments begin at the first CR contact, the centric latch of the articulator is closed, and the CR adjustments are made on the models. These centric holding contacts stabilize the mandible and place chewing forces in the long axis of the teeth. Therefore, these centric holding contacts are most important, and care should be taken to preserve them throughout the coronaplasty procedure.³ Strips of black Mylar ribbon are used to mark the initial points of occlusal contact. Optimal preservation of tooth structure, re-creation, and improvement of tooth anatomy are performed, with rules of adjustment protocols in mind.
Rule No. 1: Arc of Closure (Mesial/Distal Adjustments)—Use the mesial uppers distal lowers rule in adjusting anterior/posterior (mesial/distal) relations; ie, adjust the mesial inclines of the upper teeth (mesial uppers) and the distal inclines of the lower (distal lowers) teeth.^4,5
Rule No. 2: Line of Closure (Buccal and Lingual Adjustments)—The buccal and lingual adjustments are performed on the lingual inclines of maxillary teeth and the buccal inclines of the mandibular teeth, if the teeth are deflected towards the tongue during closure.
The buccal inclines of maxillary teeth and the lingual inclines of mandibular teeth are adjusted when the teeth are deflected towards the cheek upon closure. Ideally, there should be no contacts on the slopes of cusps when the case is completed.^4,5
Rule No. 3: Rule of Thirds—Do not attempt to adjust teeth that have more than 1.0 mm buccal-lingual discrepancy. If a tooth is significantly out of alignment in one arch, and the opposing teeth are positioned in good arch form, reduce the cusps of the malpositioned tooth and place a restoration later (do not recontour the opposing tooth that is in good arch form). If the buccal-lingual discrepancy is greater than one mm, consider orthodontic treatment. If the discrepancy is greater than 2 mm, orthognathic surgery may be necessary to reposition the arches.
Rule No. 4: Adjustments on the Teeth—When the markings of the Mylar ribbons occur on marginal ridges, cut grooves in the ridges and split the contact into 2 spots. Recreate sharp efficient anatomy by:

1. Deepening fossae and developmental grooves.
2. Deepening and/or creating supplemental grooves on inclines and marginal ridges.
3. “Shaving” contact on axial contours of teeth (buccal of lowers, lingual of uppers).
4. Do not grind cusp tips!

All the above adjustments should fall within the dictates of normal tooth morphology (Figures 22 and 23).

Adjustment Considerations for Incisive Position and Anterior Guidance
The CR adjustments should stop before mutilating the posterior teeth or encroaching on the necessary anterior space needed for proper anterior vertical and horizontal overlap. Continuing until complete, anterior closure would affect not only the function of the anterior guidance but also the display of the incisal edges and lip support. If it is necessary to leave an anterior open bite in order to have space to add length to the maxillary and mandibular anterior teeth, add wax to the maxillary anterior lingual surfaces and/or the mandibular incisal edges to complete the CR contacts.
After the anterior and posterior contacts are in harmony with the CR position of the joints, an anterior guide system still has to be developed to protect the posterior teeth during function. Unlocking the articulator and using red Mylar ribbon, an incisive pathway (adjustment position 5) is refined by adding wax, if necessary, to the linguals of the central incisors until a smooth recording of the mandibular incisors is made against the mesial marginal ridges of each incisor.
With the incisive adjustments completed, adjustments are then made at the right and left lateral border movements, ie, adjustment positions 6 and 7. Unlock the articulator and place the red marking ribbon between the posterior teeth on both sides. Move the articulator in border movements along the curved Bennett path of the articulator to mark any chewing and nonchewing side interferences. If marks are created, a decision must be made whether to remove the interferences (by reshaping the teeth) or to add wax to the lingual surface of the contralateral maxillary canine to overcome the interference. (Note: Tightening the overlap of the canines rather than reducing the posterior tooth morphology is preferred.) The distal surfaces of the maxillary teeth and the mesial surfaces of the mandibular teeth (distal of uppers, mesial of lowers) are adjusted to remove marks that occur on the cusp slopes. While adjusting lateral movements, do not remove any black CR holding contacts.
After completely removing interferences in the lateral border movements, eliminate all remaining interferences in the intermediate lateral movements (adjustment positions 8 and 9). These will usually show up on the slopes of the cusps.
If the coronaplasty has been completed correctly, the following criteria will have been met:

1. Centric contacts of the anterior teeth and posterior teeth will hold 8-µm Mylar ribbon.
2. When the casts are moved in the incisive direction, maintaining constant contact with the maxillary and mandibular incisors, an immediate posterior release of the ribbon will occur.
3. When the articulator is moved from CR in lateral border paths along the curved Bennett paths, while maintaining contact with the maxillary and mandibular canines, there will be immediate release of the marking ribbon on both the chewing and the nonchewing sides.

The purpose of the adjustments on the stone models is to have the ability to visualize how the coronaplasty will be performed intraorally.

CONCLUSION
This article has presented the treatment planning, clinical and dental laboratory procedures, coronaplasty considerations, adjustment considerations for CR tooth contacts, incisive/ surtrusive positions, and right and left medial surtrusive guidance. The next and final article in this series will discuss the application of the coronaplasty procedures on the patient models, mounted in a SCP, and the transfer of the biologic form and function to the patient.

References

1. Okeson JP. Management of Temporomandibular Disorders and Occlusion. 6th ed. St. Louis, MO: Mosby Elsevier; 2008.
2. Gibbs CH, Lundeen HC; University of Florida College of Dentistry. Introduction to human chewing [videotape]. Gainesville, FL: Learning Resources & Communications Television Division, University of Florida College of Dentistry; 1986.
3. McNeill C. Science and Practice of Occlusion. Chicago IL: Quintessence Publishing; 1997.
4. Dawson PE. Evaluation, Diagnosis, and Treatment of Occlusal Problems. St. Louis, MO: Mosby; 1974.
5. Dawson PE. A classification system for occlusions that relates maximal intercuspation to the position and condition of the temporomandibular joints. J Prosthet Dent. 1996;75:60-66.

Dr. Hunt is a graduate of Fairleigh Dickinson University Dental School and maintains a private practice in Brea, Calif. He can be contacted at kenhunt@surfside.net.

Disclosure: Dr. Hunt reports no disclosures.

Dr. Turk is a graduate of the University of Southern California Dental School and maintains a private practice in Orange, Calif. He can be contacted via the e-mail address gmturk@mouthdoc.com.

Disclosure: Dr. Turk reports no disclosures.

1. Equal intensity contacts on all teeth in a verifiable CR
2. Anterior guidance in harmony with the patient’s normal functional jaw movements
3. Disclusion of all posterior teeth when in protrusive and lateral motion away from CR
4. Restoration of any tooth surfaces that have wear through the enamel
5. Counseling of the patient to understand that teeth should not be in contact when chewing is not taking place
6. Nighttime use of an occlusal splint appliance after therapy is completed.

The sequencing of care involves a plan to systematically reach these goals in an organized way, keeping specialists, the dental laboratory team, and the patient “in the loop” throughout the course of treatment. Stability will be brought about by anterior guidance with posterior disclusion, within the patient’s envelope of function.⁵
The following report shows how a difficult case can be compartmentalized into a series of steps, leading to a successful result. In addition, it will serve to demonstrate how collaboration with specialists and knowledgeable dental laboratory technicians can pave the way.

CASE REPORT
Diagnosis and Treatment Planning: Consultation Phase
A 37-year-old male patient presented with a desire to replace his 10-year-old maxillary porcelain veneers. He stated that they had become chipped and discolored over time. A visual exam revealed multiple issues. His upper veneers were indeed chipped, stained, and “patched” with composite resin. The clinical crown on all of these veneers was shallow, causing him to squint in order to show his front teeth. His lower incisors showed excessive wear and exhibited only 2.0 to 3.0 mm of tooth structure above the mandibular gingival margins. There was a reverse curve of Spee and there were obvious spaces between mandibular anterior teeth. His lower anteriors were completely obscured by the upper teeth in closure (Before Image and Figures 1 to 3).

Before Image. Preoperative photo shows the patient struggling to show upper teeth when smiling. Note chipped and broken 10-year-old veneers and composite resin repairs.	After Image. In full smile, note the pleasing appearance of the upper anteriors and visible lower teeth. The patient reported being very comfortable. As in all severe wear cases, we have emphasized the need to wear a nightguard every night.
Figure 1. This preoperative view shows the extent of wear on lower anterior teeth as well as gingival heights of these teeth. Virtually all incisal enamel had been worn away.	Figure 2. This view shows a reverse curve of Spee and the flattening of the posterior teeth. Note the apparent abfraction lesion on tooth No. 5. Note also that the upper veneers have chipped and other restorations have broken.

Figure 3. In this view, we can see that the mandibular anterior teeth completely disappear during closure and the patient’s bite is “locked in,”causing a restricted envelope of function.

Figure 4. A temporomandibular joint (TMJ) Doppler (Great Lakes Orthodontics) was used to listen to joint sounds. The patient exhibited crepitus and an occasional click in translation and none in rotation of the joint. (Photo courtesy of Great Lakes Orthodontics.)	Figure 5. The patient wore a full-contact centric relation (CR) splint (Dawson Design) 24 hours a day, removed only for eating and cleaning for 8 weeks. He was surprised at how much better he felt during this period. He had not realized that he had temporomandibular disease symptoms until they disappeared. (Photo courtesy of Great Lakes Orthodontics.)

An interview with the patient revealed that he had occasional pain in the left and right temporomandibular joint (TMJ) areas. He had discomfort upon palpation of the facial muscles in the left and right superficial masseters and temporalis muscles as well as anterior branches of the sternocleidomastoid. Using a TMJ Doppler (Great Lakes Orthodontics) (Figure 4), crepitus was noticed on both sides with a translational click on the right. It was impossible to establish a definitive CR, and there was pain upon occlusal loading. No teeth showed signs of mobility, and a periodontal exam showed minimal pocketing. The patient agreed to wear a CR bite splint with built-in anterior guidance (Great Lakes Orthodontic Laboratory) (Figure 5) for 2 to 6 months for 24 hours daily (only to be removed during cleaning and meals.) This was planned to better diagnose TMJ issues and to allow us to ultimately mount the case in CR. Initial mounted models and photos were sent to the team at Bayview Dental Laboratory, and I discussed wax-ups and case sequencing personally with Buddy Shaefer, CDT, at the laboratory. Our first goal would be to establish a repeatable CR and to minimize TMD symptoms.

Preliminary Phase
The bite splint was seated and adjusted until all his teeth were in occlusion and posterior disclusion was evident in protrusive and lateral excursions. After several adjustments, the patient was very comfortable with the splint, and the jaw tightness he had grown used to over the years had dissipated, leaving him symptom-free. After 8 weeks of wearing the appliance full time, it was now possible to use bimanual manipulation to determine CR and his envelope of function (Dawson Design). The author has also found that a Lucia Jig (Great Lakes Orthodontics) (Figure 6) or Leaf Gauge (Great Lakes Orthodontics) (Figure 7) are other good tools to assist in finding CR (as suggested by Dr. Frank Spear).6 The patient was finally asymptomatic when loading the joints. A Denar Combi Articulator (Whipmix) and Denar Slidematic Facebow (Whipmix) was used to mount the case in centric relation. It was also noticed that there was a huge slide off his first and second molars that was shifting his bite anteriorly. We decided that removing interferences and creating a bite that would be in line with CR was possible with crown and bridge restorations from teeth Nos. 3 to 15 and 18 to 31. Opening the bite approximately 1.0 mm would help us create a healthy aesthetic occlusion without the need for orthodontics.

Figure 8. Following crown-lengthening surgery, more clinical crown was exposed on the lower anterior teeth to allow for better retention for crowns as well as a better cosmetic result.	Figure 9. The final result shows a healthy dentition with normal size lower anterior teeth. Note the more natural gingival heights and pleasing appearance.

Figure 10. Note the changes since Figure 3. When the teeth are in contact, the lower teeth are visible. Our goal of equal contacts in CR and disclusion in all excursions has been satisfied.

When presented with occlusal wear issues, we must determine how many teeth need to be restored to create an occlusion without posterior interferences. Wax-ups are needed in order to determine outside the mouth whether this goal is indeed possible. Altering anterior inclines can help create this situation, but often it is also necessary to change the posterior architecture by equilibration and/or new posterior restorations. In this case, it was deemed essential to restore posterior teeth and remove restorations, which had resulted in the anterior “slide.”
The patient consulted with Dr. Lawrence Tesser (a periodontist) who performed gingival surgery on teeth Nos. 4 to 13 and Nos. 20 to 29 to create more clinical crown length for restorative and cosmetic reasons (Figure 8). Following the crown-lengthening surgery, new models were mounted and sent to the dental laboratory team to do the wax-ups. These would be used to create temporary crowns (Integrity [DENTSPLY Caulk]) after preparing upper and lower teeth on consecutive days. In addition, preparation and reduction guides were made from the wax-ups. After the preparations were completed, the provisional crowns were fabricated (using a putty stent made from an accurate model of the diagnostic wax-up) and cemented with a noneugenol temporary cement (Tempbond NE [Kerr]). Three days later, we adjusted his bite (in CR), including in excursions, and then allowed him time to accommodate.

Impression and Provisional Phase
Three months later, the temporaries and occlusion were still stable. We removed his temporary crowns, packed retraction cord (Ultrapak Cord [Ultradent Products]), and took a vinyl polysiloxane impression of the uppers (Flexitime [Heraeus Kulzer]). Next, a bite registration (Futar D [Kettenbach]) and stick-bite was taken. We created a new lower model of the provisionals using Silgimix (Sultan Healthcare). Then, we again used the Denar Slidematic Facebow (Whipmix) for mounting and sent everything, including photos, to our dental laboratory team. We decided to use porcelain-zirconia restorations due to their strength and cosmetic appeal. New provisionals (Integrity) were made from the putty stent and cemented with a mixture of Tempbond NE and a small amount of Vaseline.

Delivery and Completion
Several weeks later, we removed the provisionals and cemented (Fuji Plus [GC America]) the upper crowns in groups of 4 at a time. We then removed the lower provisionals and took lower full-arch impressions and a new upper model in the same manner as with the upper case.
Two weeks later, the lower crowns were cemented in the same manner as the maxillary crowns. The patient felt comfortable with each set of provisionals and the final crowns (Figures 9 and 10 and After Image) and remains comfortable 2 years later.

CLOSING COMMENTS
As dentists, we face difficult cases every day in our offices. We must determine where we “want to go” with each case, and then discover how we can reach that goal. With the general dentist as the coordinator, a team concept will help us facilitate a well-focused plan. Therefore, it is important to foster a team of professionals who we can trust to help us achieve our goals for the patient. This collaborative effort can create long-term results that we and our patients can be proud of for years to come.

Acknowledgement
The author would like to thank Buddy Shaefer and Walt Richardson (Bayview Dental Laboratory) and my Dawson Academy mentors for teaching the concepts of the comprehensive exam and complete dentistry.

References

1. Dudney TE. Treating erosive tooth wear with all-ceramic restorations. Dent Today. 2009;28:100-105.
2. Hess LA. Determining the correct vertical and horizontal incisal edge position. Inside Dentistry. 2009;4:26-34.
3. Ruiz JL, Coleman TA. Occlusal disease management system: the diagnosis process. Compend Contin Educ Dent. 2008;29:148-156.
4. Dawson PE. Evaluation, Diagnosis, and Treatment of Occlusal Problems. 2nd ed. St. Louis, MO: Mosby; 1989.
5. Lerner J. A systematic approach to full-mouth reconstruction of the severely worn dentition. Pract Proced Aesthet Dent. 2008;20:81-87.
6. Spear F. Centric Relation: Bite Records . Scottsdale, AZ: Spear Education; 2011.

Dr. Auster is president and founder of the Empire State Academy of Cosmetic Dentistry: the New York, New Jersey, and Pennsylvania affiliate of the American Academy of Cosmetic Dentistry (AACD). He graduated in 1980 from the University of Pennsylvania School of Dental Medicine. He is a sustaining member of the AACD and winner of an outstanding service award from the AACD. He is a founding alumnus of the Dawson Academy. Dr. Auster has an aesthetic and restorative practice with 2 partners in Pomona, NY. He can be reached at (845) 364-0400 or via e-mail at drpauster@gmail.com.

Disclosure: Dr. Auster reports no disclosures.

This clinical report presents a conservative and a dynamic approach to the aesthetic correction of a tapered upper jaw with composite resin. Due to the complexity of this aesthetic rehabilitation, the clinical treatment was divided into 2 phases: an initial correction and a final correction. Part 1 of this article described the initial aesthetic correction and the treatment planning of the final correction by means of digital imaging. Part 2 of this article describes in detail the utilization of a direct composite mock-up and the step by step clinical procedure of the final treatment.

INTRODUCTION
In cases of complex dental irregularities or jaw size abnormalities, it is often preferable to split the treatment into 2 or more phases. An extensive aesthetic correction could be very difficult for the patient to become familiar with and accept if completed in one session.^1,2 Therefore, an initial correction can be made in order to help the patient get used to the new look and feel. After this first aesthetic correction, it could be easier for the patient to imagine more precisely the outcome of a more extensive aesthetic correction. A very good tool that can be used to visualize the final aesthetic result is a digital imaging and image manipulation. Visualization of the aesthetic result before the treatment serves to improve clinician-patient communication.^3-8 If patients can actually see and evaluate a suggested aesthetic result in advance, the decision whether or not to move on with the treatment is made more easily.^6-8 Another valuable method for treatment planning in complex dental cases can be the utilization of a composite mock-up. This procedure will help the patient not only to visualize the result but also to feel the proposed physical changes in the oral cavity that will occur as a consequence of the proposed dental treatment. In this stage, patients will still have the opportunity to cancel the final treatment if not satisfied. Conclusively, the chance for post-treatment disappointment will be diminished.

CASE REPORT
(A Recap of the Diagnosis and Treatment Plan From Part 1)
A 38-year-old male patient with a tapered upper jaw, moderate overbite, midline displacement, and extensively restored anterior teeth (tooth No. 9 had been endodontically treated) expressed the need for improved aesthetics of his smile (Figures 1 and 2). After evaluation of the patient’s wishes and expectations, the clinical data were collected. For this particular patient, an orthodontic treatment was not a consideration, and he wished for an optimal aesthetic result with minimum tooth preparation of healthy tissues. However, for the authors it was clear that an extensive treatment with composite was necessary in order to meet the patient’s desire for improved dental aesthetics. The treatment was therefore divided into 2 phases. The first phase was reserved for the initial aesthetic correction of the frontal area; this treatment was described in part 1 of this article “Improving Aesthetics in a Narrow Jaw With Composite, Part 1” at dentistrytoday.com. The patient was informed that depending upon his satisfaction after the initial treatment, a choice could be made to continue with more extensive treatment utilizing composite resin restorative materials.

Figure 1. Preoperative frontal view.	Figure 2. Preoperative lateral view.
Figure 3. Frontal view, 2 years after the initial treatment.	Figure 4. Lateral view, 2 years after the initial treatment.

Mock-Up
Two years after the initial treatment, the patient was still happy with his restorations (Figures 3 and 4). However, he was now ready to undergo the more complex and extensive treatment that had been presented using the digital mock-up. The narrow (omega-like) upper jaw was still a big aesthetic problem for him and he wanted it to be optimally improved with composite.
By using composite mock-ups, a dentist can establish physical demonstrations of the treatment planning for each particular case. Moreover, patients can see and feel the changes in their mouth, thus enabling them to share in the decisions involved prior to the treatment. Composite mock-ups are also an excellent tool to visualize the light behavior on the modified tooth surfaces.⁵ The composite mock-up approved by the patient can be captured by dental impressions and photographs, which can be used for model analysis and treatment support, especially in cases when porcelain crowns or facings are required.⁵

Figure 5. Dental brush (moisturized with an unfilled resin) was used with a relatively low viscosity composite resin to create the mock-up.	Figure 6. Nonadhesive application of composite was done to allow for trouble-free removal of composite.

Figure 7. Frontal view of the mock-up. (Note that the incisal part of the teeth was positioned toward vestibular to improve the aesthetics of the buccal corridor.)

In this particular patient case, where the narrow aspect of the jaw had to be corrected, the composite mock-up was an outstanding method to visualize the effect of teeth enlargement. The authors used a soft dental brush Quast (Cavex), slightly moisturized with an unfilled resin, Heliobond (Ivoclar Vivadent) and composite resin (Quadrant Anterior Shine [Cavex]) of a relatively low viscosity (flowable composite) to accomplish fine handling and smooth application of the material (Figure 5). Composite was applied directly over the buccal surfaces without the use of etchant and adhesive in order to allow for trouble-free removal of the composite (Figure 6). It was spread over the buccal surfaces of the teeth, paying special attention to the sculpting of new and more vestibular positioned incisal edges (Figure 7). This approach was necessary in order to test the effect of the teeth enlargement on the lips and cheeks.^9-11

Color Determination
The patient was satisfied with the color of his upper right central incisor tooth No. 8; therefore, this tooth was used as a target for color determination. Its color was measured with SpectroShade Micro (MHT) and expressed in CIEL*a*b* values (Figure 8).^12,13 The closest match established was comparable to the Vita classical shade tab A2. Color difference ∆E between the tab A2 and tooth No. 8 was also calculated. It appeared that the color difference was visually perceptible for each segment of the tooth:¹⁴
• ∆E cervical = 3.63
• ∆E middle = 2.33
• ∆E incisal = 4.97

Figure 8. Digital color analysis with SpectroShade Micro (MHT).	Figure 9. Tooth color determination with in-office fabricated 2-layered composite tabs.

The difference was mainly in yellowness because the tooth was more yellow than the tab (Figure 8). In order to get a “natural look” of the composite restorations, color was determined using custom made stratified (layered) composite tabs fabricated by the authors (Figure 9).^10,15,16 The unique stratified tabs were composed of 2 composite labels frequently used by the authors. The body of the tabs consisted of a hybrid composite (Z250 [3M ESPE]) in 2 chromatic expressions: one for the cervical part (more saturated), A3; and one for the middle/incisal part, A2. The superficial layer of the tabs was built up with the microhybrid composite Quadrant Anterior Shine in the same chromatic range as the hybrid layer. The CIEL*a*b* values of the self-made tabs were also measured with the SpectroShade Micro and the most similar layered composite tab was selected for the tooth buildup. The selected shade tab for this case consisted of: Layer 1 – A3 cervical + A2 middle/incisal (Z250) and Layer 2 – A3 cervical + A2 middle/incisal (Quadrant Anterior Shine) (Figure 9).

Clinical Procedure for Composite Veneers
Treatment started with local anesthesia, and a rubber dam was applied to prevent patient discomfort during the treatment and to assure a controlled working area. Then, the old restorations and the incisal edges, which had to be positioned toward vestibular, were slightly prepared, the teeth surfaces sandblasted with aluminum oxide (27 µm), etched, rinsed, dried, and treated with a 3-step adhesive (All Bond 2 [BISCO]) procedure (Figures 10 to 12). The proximal aspects of all teeth were consecutively separated with transparent matrices (Directa Matrix Strips [Directa]) and hybrid composite (Z250) was applied mesially, distally, and on the incisal edges in order to position those buccally (Figure 13). In this way, strong hybrid-composite frameworks were prepared for the build-up of microhybrid composite facings.10,17 In this stage, the restorations were only roughly polished with a diamond bur and the rubber dam was removed so that the occlusion and position of the incisal edges could be verified (Figure 14).

Figure 10. In maximum occlusion, the lateral cross-bite is assessable.	Figure 11. Teeth are prepared for buildup of hybrid composite framework. Teeth Nos. 8 and 10 are proximately reduced to allow for the widening of tooth No. 9.
Figure 12. Occlusal view shows that the enamel has been reduced occlusally (from the canine and premolars) to allow for composite addition and correction of cross-bite without resulting in over-contoured teeth.	Figure 13. The incisal part of the teeth was moved buccally with hybrid composite. The teeth were prepared for aesthetic facings with microhybrid composite.
Figure 14. After the rubber dam was removed, the occlusion was checked and adjusted, and the new position of the incisal edges was also evaluated.	Figure 15. The metal matrix band (Automatrix NR [DENTSPLY Caulk]) was applied around the vestibular surface of tooth No. 11 with a 45° orientation. It was then stabilized with wooden wedges.
Figure 16. Composite was polymerized during and after the removal of the metal band.	Figure 17. The excess of composite was removed. Then, the transition area in the cervical part was polished with fine diamond burs.
Figure 18. The facing for tooth No. 10 was the next to be built up using a matrix band.	Figure 19. Composite was first applied with an Ash 49 instrument. The greatest mass was positioned in the cervical part and then thinned out toward the middle part.

A composite facing was first completed on tooth No. 11. A metal matrix (Automatrix NR [DENTSPLY Caulk]) was passed through the contact points easily and served to separate the facing from the neighboring teeth. The matrix was slightly buckled in order to fit the cervical borderline perfectly, then dental wedges were used proximally in order to prevent over-contouring, leakage of saliva, crevicular fluid, and/or blood. That left the buccal surface of the tooth surrounded by matrix and wedges and very well isolated for the purpose of the adhesive exposure (Figure 15). The buildup of the facing was carried out with the application of a chromatic version of microhybrid composite (Quadrant Anterior Shine ) on the cervical part of the tooth No. 11; and then the application of a less chromatic version of composite on the middle and the incisal part. After curing, the matrix was removed and the buccal surface was contoured with a fine grit diamond bur (FG 249U012 [Horico]) (Figures 16 to 18).
Continuing with tooth No. 10 (Figure 19), the first portion of composite was syringed against the matrix and then adapted with an Ash 49 instrument, making sure that no air bubbles were captured (Figure 20). Hereby, the greatest mass was positioned in the cervical part and depleted towards the middle part. Directly after the first composite application, the dental brushes (Quast and Flat Brush [GC America]) were utilized to smoothly spread the composite (Figure 20). Consecutive layers of composite (A3, followed by A2), were applied like “roof tiles” in order to acquire a natural-depth appearance. The veneer was cured during the layering, and once again after the removal of the metal matrix (Figure 21).

Figure 20. A dental brush was used to spread composite smoothly over the entire surface.	Figure 21. Lateral view after polymerization of tooth No. 11 and tooth No. 10 before polishing.
Figure 22. Lateral view of the canine and lateral incisor after polishing.	Figure 23. Frontal view in maximum occlusion.
Figure 24. Occlusal view, 2 months postoperatively.	Figure 25. Frontal view (in detail), 2 months postoperatively.

Figure 26. The improved smile of the patient, 2 months after treatment.

Every composite facing was contoured with a fine diamond bur (FG 249U012), paying careful attention to the transitional area between the restoration part formed by matrix, and the one formed by the dental brush (Figure 22). Facings were then consecutively applied to the other incisors, canines, and premolars, taking into account the harmony in their mesiodistal dimensions.10
After 3 months, the patient came into the office for the final evaluation. This time period was needed for the patient to get used to the new feel and appearance of the teeth and to discover any possible problems. During this visit, the patient’s dental hygiene was checked and the composite veneers were polished to an optimal high luster. Prior to final polishing, the restorations were once again evaluated for proper occlusion and articulation. Also, the desired natural-appearing morphology was evaluated with special attention to the incisal/occlusal aspect, which is essential for natural aesthetics (Figures 23 and 24).9,10 The teeth looked relatively long, so the cervical contouring was refined and enhanced with a pear-shaped bur (FG 379EF023 [KOMET]) in order to suggest a less apically located crown (Figure 25). Next, the surface design and light reflections were assessed in different illuminations and from different directions, and corrected where needed; then the veneers were polished with polishing cups (Politip P large cup [Ivoclar Vivadent]) and Diamond Polishers large cup [Heraeus Kulzer]), ensuring very smooth surfaces (Figures 24 to 26). Finally, the patient was instructed how to brush and clean interproximally with dental floss (Dentotape [Johnson & Johnson]) in order to maintain the aesthetic result as long as possible.

CONCLUSION
Nowadays, trend-setting industries often set the tone for aesthetics in the public eye, but in order to experience something “beautiful,” a strong intimate affection for the work that has been done needs to be present. This feeling is utterly personal. Therefore, the one who desires an aesthetic improvement, and the one who is supposed to create it, needs to explain their aesthetic visions to each other before the actual process of change takes place. If the patient and the creator only verbally describe their aesthetic wishes to each other without having the opportunity to visualize them or to feel the alterations, the outcome of any treatment and their mutual satisfaction could be undermined.
Relatively simple and nonexpensive techniques can be used to help visualize the intended treatment result before the actual treatment has taken place. These techniques include employing computerized image manipulation and composite resin mock-ups; these can be seen respectively as a 2- and 3-dimensional means of visualization. Using these techniques, dentists can also discover whether the intended aesthetic result is feasible and what possible obstacles might be encountered during the course of treatment; this can be essential for properly treatment planning a case. It is also to be expected that patients may become more interested in the treatment that has been presented to them even though they may not have wished that improvement previously. However, if dentists decide to utilize visualization techniques as tools “to sell” a particular treatment, they must be very well aware that their subjective clinical abilities and any existing dental/patient limitations that could impact the final clinical outcome.

References

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2. Nuy M, Gordijn B.Cosmetic dentistry. An ethical reflection on the boundaries of embellishment [in Dutch]. Ned Tijdschr Tandheelkd. 2003;110:154-158.
3. Goldstein CE, Goldstein RE, Garber DA. Imaging in Esthetic Dentistry. Chicago, IL: Quintessence Publishing; 1998.
4. Roeters J, de Kloet H, Jeurissen A. Handboek Voor Esthetische Tandheelkunde. Nijmegen, The Netherlands: STI; 1998, 2005.
5. Atlas of PLVs. In: Gurel G. The Science and Art of Porcelain Laminate Veneers. Chicago, IL: Quintessence Publishing; 2003: Chapter 7.
6. Papasotiriou OS, Nathanson D, Goldstein RE. Computer imaging versus conventional esthetic consultation: a prospective clinical study. J Esthet Dent. 2000;12:72-77.
7. Goldstein RE. Attitudes and problems faced by both patients and dentists in esthetic dentistry today: an AAED membership survey. J Esthet Restor Dent. 2007;19:164-170.
8. Goldstein RE, Garber DA. Improving aesthetic dentistry through high technology. J Calif Dent Assoc. 1994;22:23-24, 26, 28-29.
9. Vanini L, Mangani F, Klimovskaia O. Conservative Restoration of Anterior Teeth. Viterbo, Italy: ACME; 2005.
10. de Kloet HJ. Esthetische tandheelkunde met facings van composietmateriaal. ACTA Quality Practice. 2006;1:26-37.
11. Talarico G, Morgante E. Psychology of dental esthetics: dental creation and the harmony of the whole. Eur J Esthet Dent. 2006;1:302-312.
12. Dozic A. Electronic tooth-color measurement. In: Dozic A. Capturing Tooth Color. Wageningen, The Netherlands: Ponsen & Looijen BV; 2005:23-32.
13. Dozić A, Kleverlaan CJ, El-Zohairy A, et al. Performance of five commercially available tooth color-measuring devices. J Prosthodont. 2007;16:93-100.
14. Johnston WM, Kao EC. Assessment of appearance match by visual observation and clinical colorimetry. J Dent Res. 1989;68:819-822.
15. Dozic A. Kleurdiagnose. ACTA Quality Practice. 2005;1:31-35.
16. Dozic A. Praktische werkwijzen om voorspelbaarheid van esthetische kleur- en vorm-uitkomst van composiet-restauraties te vergroten. ACTA Quality Practice. 2008;4:19-28.
17. Meijering AC. A clinical study on veneer restorations [thesis/dissertation]. Nijmegen, The Netherlands: Katholieke Universiteit Nijmegen; 1997.

Dr. Dozic is assistant professor at Academic Centre for Dentistry in Amsterdam, the Netherlands, and guest professor at Faculty of Dentistry in Sarajevo, Bosnia, and Herzegovina. She also works in a private dental practice specializing in restorative dentistry in Amsterdam. She received her PhD in Dental Materials Sciences on theme “color of teeth” in 2005. She is lecturing in a master phase of dental curriculum and postacademically covering different aspects of aesthetic dentistry. She is also conducting research implying: electronic color determination, optical properties of dental materials, color change of teeth due to external factors, and the aesthetic outcome of different restorative methods in clinical dentistry. She has published more than 26 articles internationally and is the editor of the Annual Book About Dental Esthetics in the Netherlands. She maintains membership in many professional associations and academies. She can be reached at (0031) 617452560 or via e-mail at a.dozic@acta.nl.

Disclosure: Dr. Dozic reports no disclosures.

Dr. de Kloet studied dentistry at Free University in Amsterdam, the Netherlands. Since his graduation in 1974, he has been involved in research and clinical practice in the field of direct adhesive-aesthetic-composite dentistry, exploring the technical and aesthetic limits of composite materials. Currently, Dr. de Kloet works part-time at the Academic Centre for Dentistry in Amsterdam, where he organizes postgraduate courses in Holland and Belgium. He is co-author of more than 30 publications and 2 textbooks about aesthetic composite dentistry, in Dutch and German, with Joost Roeters of the Dental School of Radboud University, Nijmegen. He lectures internationally for 3M ESPE, Kerr, and Ivoclar Vivadent and for national and local associations of dentistry. He also is a renowned lecturer on digital dental photography. He can be reached via e-mail at h.dekloet@chello.nl.

Disclosure: Dr. de Kloet reports no disclosures.

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CASE REPORT
Diagnosis and Treatment Planning
A 38-year-old male patient with a tapered upper jaw, moderate overbite, midline displacement, and extensively restored anterior teeth (tooth No. 9 had a history of endodontic treatment) expressed the need for improved aesthetics of his smile (Figures 1 and 2). After evaluation of the patient’s wishes and expectations, the clinical data were collected. Gypsum models and 3 identical wax indices were made for the occlusion and articulation analysis and for the initial wax-up (Figure 3). For this particular patient, an orthodontic treatment was not a consideration and he wished for an optimal aesthetic result with minimum tooth preparation of healthy tissues.

Figure 1. Preoperative frontal view.	Figure 2. Preoperative lateral view.

Figure 3. A diagnostic wax-up model was fabricated to assess the practical possibilities for improved aesthetics and to produce a silicone index for later use in the provisionalization phase.

The authors could clearly see that a more extensive treatment with composite was required in order to meet the patient’s desire for improved dental aesthetics. Therefore, the treatment was divided into 2 phases; the first phase was reserved for the initial aesthetic correction of the frontal area.
In order to establish better symmetry in the frontal area with only slight corrections, it was chosen to make a composite buildup of the left central incisor No. 9, a Class IV composite restoration of the mesioincisal aspect of the right central incisor No. 8, and composite veneers on the left lateral and central incisors, teeth Nos. 9 and 10. The second phase of the treatment was reserved for composite buildup of the buccal and occlusal aspects of the 4 upper incisors, left and right canines, and the premolars; this would be done to simulate an expansion of the buccal corridor. The patient was informed that, depending upon his satisfaction after the initial treatment, a choice could be made to continue with more extensive treatment with composite.

Initial Treatment
Before the start of the initial treatment, the basic color of anterior teeth was assessed visually using VITA Classical shade tabs [Vident]. The determined color was A3. After color determination, the old fillings in the central incisors (Nos. 8 and 9) were removed and the left central and lateral incisors (Nos. 9 and 10) were slightly grinded buccally in order to prepare the surface for composite facings (Figure 4). The buildup of the facings was done by freehand technique with aid of a silicone index (Memosil [Heraeus Kulzer]) that was fabricated from the initial diagnostic wax-up.6,7 The silicone index was cut through in order to obtain a palatal and a buccal section. The palatal index helped to appropriately shape the palatal surface of the incisors and to omit incisal disturbances and material excess.7 The buccal section of the index was used to get an indication whether the amount of tissue that has been removed buccally provided sufficient space to mask the teeth discolorations with composite.2 In order to keep the mesial and distal aspect of the restored teeth in a tight but separated contact, very thin Teflon tape (0.02 mm) was used (Figure 5).6 First the tooth No. 8 was restored in order to assess the vertical midline and to determine the shape of tooth No. 9, then mesial and distal surfaces of each upper incisor were restored with hybrid composite (Z250 [3M ESPE]). Thereafter, the facings were made using the transparent Contour strips (Ivoclar Vivadent) with a microhybrid composite (Anterior Shine [Cavex]) (Figure 6).

Figure 4. Maxillary anterior teeth after the removal of the old composite restorations.	Figure 5. Palatal index and Teflon tape in situ for buildup of tooth No. 9.
Figure 6. The use of Contour strip (Ivoclar Vivadent) for proximal and vestibular buildup.	Figure 7. Frontal view directly after the initial aesthetic correction.
Figure 8. Lateral view 2 years after the initial correction.	Figure 9. Two years after the initial aesthetic correction.

The patient was very satisfied with the look of his anterior teeth after the initial treatment (Figures 7 to 9). Within several weeks he had gotten accustomed to the new form and function of his teeth. This resulted in his wish to find out more about the possibilities to improve his smile with more extensive treatment, as suggested earlier. In this stage, the authors decided to visualize the possibilities of the more extensive treatment using a digital mock-up.

Digital Imaging and Image Manipulation (Visualization)
Digital imaging is a noninvasive and effective communication means for presentation of treatment options.^3,4,8 A clinician can use digital imaging to discover whether the possible treatment options can satisfy the patient’s needs and to discover possible obstacles (Figures 10 and 11).^3-5

Figure 10. Example of digital imaging for closing of diastemas.	Figure 11. Example of digital imaging for the replacement of restorations and adjusting the shape of teeth.

For the purpose of the digital mock-up of the presented case, standardized photographs of the initial treatment result were used. They were analyzed in order to discover discrepancies to normal jaw relations and symmetry, and to brainstorm about possible corrections with composite resin. For dental imaging, Paint Shop Pro X and a graphic pen tablet (Wacom [Bamboo One]) were used. First, the original photograph was cut out (Figure 12) with the “crop” tool, then copied and pasted underneath the original (after enlarging the canvas) (Figures 13 and 14). The upper part in the enlarged canvas was used as a reference and the lower part for imaging (Figure 15). Using the tools “push,” “select,” “copy,” “paste as selection,” and “darker/lighter” (Figure 16), the original image was manipulated toward a possible treatment result, showing the changes possible and also the limitations in this particular case (Figure 17). Finally, the digital transparent molds were made and placed (“pasted”) on top of the original photograph as a layer with 50% transparency (Figure 18). The patient was impressed with the aesthetic possibilities. He took the photographs of the planned final result with him in order to discuss the proposed changes with his partner.

Figure 17. The new look of the smile after the image manipulation.	Figure 18. The manipulated image was made transparent (50%) and then projected over the original.

The appointment for the composite mock-up was made after 4 weeks. The purpose of the composite mock-up was to improve the alterations in the mouth and to let the patient feel whether he can get used to possible changes. This mock-up will be discussed in part 2.

CONCLUSION
Thanks to the improved strength and superb optical properties of modern composites, aesthetic treatments with this class of restorative materials are becoming more and more popular compared to more invasive procedures. This material is an excellent medium for dynamic and reversible aesthetic alterations. It offers possibilities for phased treatment in more complex cases and finally, if necessary or desired in the future, orthodontics, surgery, and irreversible restorative techniques are still obtainable.
A totally noninvasive method for visualization of treatment planning is digital manipulation of dental images. A relatively inexpensive and simple to use digital imaging program (eg, Paint Shop Pro X) is available for such purposes. All patients (or family members and significant others) can see the proposed aesthetic corrections, take the time to think it through, and eventually give their opinion about it before the actual treatment has started. A patient can also get a good idea about the possible limitations of the treatment, which could enhance satisfaction with the final result.

References

1. Roeters J, de Kloet H, Jeurissen A. Handboek Voor Esthetische Tandheelkunde. 2nd ed. Nijmegen, The Netherlands: STI; 2005.
2. Atlas of PLVs. In: Gurel G. The Science and Art of Porcelain Laminate Veneers. Chicago, IL: Quintessence Publishing; 2003:231-344.
3. Papasotiriou OS, Nathanson D, Goldstein RE. Computer imaging versus conventional esthetic consultation: a prospective clinical study. J Esthet Dent. 2000;12:72-77.
4. Goldstein RE. Attitudes and problems faced by both patients and dentists in esthetic dentistry today: an AAED membership survey. J Esthet Restor Dent. 2007;19:164-170.
5. Goldstein RE, Garber DA. Improving aesthetic dentistry through high technology. J Calif Dent Assoc. 1994;22:23-24, 26,28-29.
6. Dozic A. Praktische werkwijzen om voorspelbaarheid van esthetische kleur- en vormuitkomst van composietrestauraties te vergroten. ACTA Quality Practice. 2008/2009;4:19-28.
7. Vanini L, Mangani F, Klimovskaia O. Conservative Restoration of Anterior Teeth. Viterbo, Italy: ACME; 2005.
8. Goldstein CE, Goldstein RE, Garber DA. Imaging in Esthetic Dentistry. Chicago, IL: Quintessence Publishing; 1998.

Dr. Dozic is assistant professor at Academic Centre for Dentistry in Amsterdam, the Netherlands, and guest professor at Faculty of Dentistry in Sarajevo, Bosnia, and Herzegovina. She also works in a private dental practice specializing in restorative dentistry in Amsterdam. She received her PhD in Dental Materials Sciences on theme “color of teeth” in 2005. She is lecturing in a master phase of dental curriculum and postacademically covering different aspects of aesthetic dentistry. She is also conducting research implying: electronic color determination, optical properties of dental materials, color change of teeth due to external factors, and the aesthetic outcome of different restorative methods in clinical dentistry. She has published more than 26 articles internationally and is the editor of the Annual Book About Dental Esthetics in the Netherlands. She maintains membership in many professional associations and academies. She can be reached at (0031) 617452560 or via e-mail at a.dozic@acta.nl.

Disclosure: Dr. Dozic reports no disclosures.

Dr. de Kloet studied dentistry at Free University in Amsterdam, the Netherlands. Since his graduation in 1974, he has been involved in research and clinical practice in the field of direct adhesive-aesthetic-composite dentistry, exploring the technical and aesthetic limits of composite materials. Currently, Dr. de Kloet works part-time at the Academic Centre for Dentistry in Amsterdam, where he organizes postgraduate courses in Holland and Belgium. He is co-author of more than 30 publications and 2 textbooks about aesthetic composite dentistry, in Dutch and German, with Joost Roeters of the Dental School of Radboud University, Nijmegen. He lectures internationally for 3M ESPE, Kerr, and Ivoclar Vivadent and for national and local associations of dentistry. He also is a renowned lecturer on digital dental photography. He can be reached via e-mail at h.dekloet@chello.nl.

Disclosure: Dr. de Kloet reports no disclosures.

Figure 1. Spectra (Air Techniques) camera lens and LED lights. Figure 2. Spectra camera with autoclavable spacer in position.

EARLY DETECTION IS KEY
Detecting the bacteria associated with caries can make a real difference in overall patient care. Early detection is often the key to effective caries management. Although the tooth may appear healthy on the surface, its real condition underneath the surface—especially true for fissure caries—is often hard to detect. Use of an explorer can lead to cavitation of early lesions preventing remineralization due to the surface disruption or may lead to an acceleration of the caries process when the weak enamel overlaying the demineralized area is physically broached by an instrument.
      Enhanced caries detection, which supports minimally invasive treatment regimens, along with simplified case presentations, make Spectra an innovative, indispensable tool.
     Spectra offers a different view to noninvasive caries detection, enabling reliable tooth-by-tooth detection of fissure caries and caries on smooth surfaces. While other devices use numeric indicators to signal the presence of decay, Spectra uses a color visual system with software analysis to provide a picture of the tooth with visual representation of where tooth structure is deteriorating. Spectra is a fluorescence-based caries detection system that has received FDA clearance. Spectra’s LEDs project high-energy blue light onto the tooth surface. Light of this wavelength stimulates bacteria to fluoresce red, whereas healthy enamel fluoresces green.
      Flurorescence procedures are based on illustrating certain fluorescence substances like porphyrins, which grow in bacterial populated areas. When the area is stimulated with light of a certain wavelength, the molecules absorb the light energy and release part of the light energy with a different wavelength.
     Spectra is similar to an intraoral camera in appearance and function. Yet, where an intraoral camera has white LEDs surrounding the lens, Spectra has an array of 6 LEDs emitting a 405 nm blue-violet light (Figure 1). Spectra connects to the operatory computer via a USB connector and is operated by proprietary software. The device is sheathed in a single-use disposable intraoral camera sleeve for sterility and an autoclavable rubber “spacer” is placed over the sheath at the end of the lens (Figure 2). The spacer eliminates ambient light and maintains a consistent distance between the device and the tooth surface, so images are reproducible and consistent. Spectra is both self-calibrating and portable, making it easy to use in offices with multiple operatories.

SPECTRA CARIES DETECTION PROTOCOL
The practitioner or hygienist, following removal of any plaque and tartar, which may interfere with caries detection, then utilizes the Spectra to capture pictures of the teeth. The spacer is placed over the dry tooth and kept in contact with the tooth to be analyzed, and then Spectra is activated to capture the image. When the image is frozen on the screen, either the Visix proprietary software (a special version of Visix is supplied with the Spectra system) or a twain driver (also available, allowing direct acquisition into most dental practice management software programs) analyzes the image, running an algorithm. Following instantaneous software analysis, the captured image on the computer of the tooth shows enamel breakdown due to caries in a graphic representation similar to weather radar images. Images can be saved to monitor areas or to gauge the effectiveness of remineralizing therapy.
     It has long been recognized that the cariogenic bacteria Streptococcus mutans produces special metabolites called porphyrins. These porphyrins fluoresce when exposed to a 405-nm light. This fluorescence is detected by the Spectra device and is visually identified. The denser the bacterial colonization, the more intense the red fluorescent signal will be. The software analysis then provides the practitioner with an estimate of the depth and extent of the caries based on the color map produced, depending on the degree of fluorescence. These colors indicate the possible depth of carious involvement and help guide the practitioner to the appropriate treatment (Table). The image and corresponding color map also help in patient education and assist the patient in understanding why the avenue of treatment suggested is being recommended despite a possible absence of any tooth sensitivity.
     

Figure 3. A healthy premolar image taken under detection mode with the Spectra unit.	Figure 4. A healthy premolar image taken with the Spectra unit under analyze mode, showing no highlighted areas on the tooth surface. The red area shown is gingival tissue which may have bacteria containing porphyrins compounds.
Figure 5. A premolar image taken with the Spectra unit under detection mode showing healthy tooth structure as green and questionable areas as red.	Figure 6. A premolar image taken with the Spectra unit under analyze mode demonstrating areas that may become carious in the future, allowing better patient education.
Figure 7. Molar captured with Spectra in detection mode showing suspect areas in the pits and fissures.	Figure 8. Molar captured with Spectra under analyze mode indicating a high value at the central pit.
Figure 9. Preparation following removal of an existing composite restoration taken with Spectra.	Figure 10. Preparation following removal of an existing composite restoration taken with Spectra under analyze mode, indicating decay still present in the mesial aspect of the preparation.

The Spectra caries detection system provides the practitioner with a baseline for that patient’s particular tooth, allowing monitoring on subsequent recall appointments. Unlike competitive devices, the entire occlusal surface is analyzed and the image can be saved for future reference. Additionally, when remineralization procedures are employed, the practitioner can monitor how effective the remineralization proceeding.
     

Table. Interpretation of Spectra (Air Techniques) data.

An added benefit to the Spectra device is in identifying bacteria-affected dentin during tooth preparation. Traditional methods, which include caries-indicating dye, have been reported to provide false positive or negative information which may lead to carious affected dentin being left or over excavation of healthy tooth structure. The fluorescence captured by the Spectra unit identifies porphyrins associated with S mutans and thus dentin in the preparation that fluoresces indicates the presence of bacteria in the dentin and can guide the practitioner to better decisions on caries excavation.

CASE EXAMPLES
Spectra can be utilized as a screening device at recall appointments. A healthy tooth may demonstrate slight fluorescence in the pits and fissures when observed under detection mode (Figure 3), but when switched to analyze mode, values should be zero in these areas (Figure 4). Whereas, a tooth with a similar appearance under detection mode (Figure 5) may, when switched to analyze mode, demonstrate some values in the pits and fissures (Figure 6). Low values in the pits and fissures may indicate continued observation of these areas or suggest either remineralization procedures be used or sealants placed. These images may also be used to educate the patient on areas of the tooth that require more home care attention. Teeth that show more extensive red fluorescence in the pits and fissures (Figure 7) may demonstrate higher values in these areas (Figure 8), leading the practitioner to perform conservative restorations versus observation until the caries have penetrated deeper and wider.
     Another useful adjunct is in determining caries removal during preparation. A patient presented with a defective composite restoration in a mandibular molar. The Spectra unit was utilized following removal of the existing restoration to identify residual decay. Under detection mode, small areas of red fluorescence were noted (Figure 9). But, when switched to analyze mode, a higher value was noted in the mesiolingual aspect indicating that further excavation was needed at this spot (Figure 10).
     High fluorescence associated with gingival tissue may be due to the presence of porphyrin-associated bacteria on the soft tissue. Some of the examples illustrated above demonstrate this. This can be used as an educational aid, directing the patient to areas that need better home care.

CONCLUSION
An innovative noninvasive caries detection system, Spectra shows the patient the presence of harmful bacteria in the mouth, and corresponding oral hygiene status. This can help motivate the patient to carry out a regimen of better dental care—both at home and through regular checkups and cleanings at the office.
     Patient communication is important in our interactions when suggesting treatment. Frequently what is obvious to the practitioner, especially with regards to initial caries, is not clear to the patient. Patients usually base their decision process on initial fillings on sensitivity in the tooth and their trust in the practitioner. But when a tooth is not sensitive, it can be difficult to get the patient to move forward with early treatment. The Spectra system is another tool in our armamentarium aiding us in both diagnosis and communication with regards to incipient pit and fissure caries at the early stages. As an image is captured and values are set for specific areas of the occlusal of the posterior teeth, monitoring progress of the area when observation is decided versus clinical treatment. This allows patients to be a partner in their dental treatment and better understand the options of treatment or observation.

Additional information
For additional information, contact Air Techniques by calling (800) AIR-TECH or visit airtechniques.com.

References

1. König K, Flemming G, Hibst R. Laser-induced autofluorescence spectroscopy of dental caries. Cell Mol Biol (Noisy-le-grand). 1998;44:1293-1300.
2. Buchalla W. Comparative fluorescence spectroscopy shows differences in noncavitated enamel lesions. Caries Res. 2005;39:150-156.
3. Zezell DM, Ribeiro AC, Bachmann L, et al. Characterization of natural carious lesions by fluorescence spectroscopy at 405-nm excitation wavelength. J Biomed Opt. 2007;12:064013.
4. Buchalla W, Lennon AM, Attin T. Comparative fluorescence spectroscopy of root caries lesions. Eur J Oral Sci. 2004;112:490-496.

Dr. Kurtzman is in private general practice in Silver Spring, Md, and is a former assistant clinical professor at the University of Maryland, department of endodontics, prosthetics and operative dentistry. A former assistant program director for a university-based implant maxi-course, he has earned Fellowship in the AGD, American College of Dentists, International Congress of Oral Implantologists (ICOI), Pierre Fauchard in the American College of Dentistry, Academy of Dentistry International, Mastership in the AGD and ICOI and Diplomat status in the ICOI and ADIA. He has lectured internationally on the topics of restorative dentistry, endodontics and implant surgery and prosthetics, removable and fixed prosthetics, periodontics, and has more than 180 published articles. He is privileged to be on the editorial board of numerous dental publications and is a consultant for multiple dental companies. He can be reached via e-mail at dr_kurtzman@marylandimplants.com.

Disclosure: Dr. Kurtzman reports no disclosures.

Advances in surgical techniques, such as sinus grafting and implant placement, in conjunction with the advances in restorative materials and techniques, allow patients to regain the aesthetics and function of their original dentition—perhaps even better. The key to the successful and predictable use of advanced surgery and materials is being able to identify the critical diagnostic variables, and to organize them in a manner that will create a treatment plan (and/or alternative plan) that addresses the patient’s chief complaint and dental health. The goal of this article is to assist the dentist in identifying and organizing all the variables of treatment that are responsible for creating predictable outcomes.

Figure 1. Preoperative full-face view.	Figure 2. Preoperative smile.

Figure 3. Maximum intercuspation. (Note the severe wear).	Figure 4. Protrusive position.
Figure 5. Right-lateral view.	Figure 6. Left-lateral view.
Figure 7. Mandibular occlusal view.	Figure 8. Panoramic radiograph.
Figure 9. Cephalometric radiograph. (Note severe cant of the posterior maxillary molars and angle of the occlusal plane).	Figure 10. Mounted diagnostic casts at the proposed OVD and CR position. (Note the supra-eruption of teeth Nos. 2 and 3 along with the expansion of the right maxillary tuberosity).
Figure 11. Left view of the diagnostic casts demonstrating the supra-eruption of Nos. 14 and 15.	Figure 12. Left-lateral view showing the mandibular anterior cross section and the anterior angulation of the mandibular incisors. The maxillary occlusal plane has been diagnostically corrected, along with the maxillary incisal edge position.

Figure 13. Anterior diagnostic tooth set-up, done to establish the mandibular incisal edge postion.

A review of the cephalometric image revealed that the patient exhibited an occlusal vertical dimension (OVD) within normal limits; and this was also clinically demonstrated by examination of his lip support and facial profile, as well as speech evaluation. Though the anterior teeth were significantly shortened, the OVD would not allow for an increase to achieve restoration of the maxillary anterior teeth to proper form and length. Though many times, especially in Class II skeletal relationships, the OVD can be modified to achieve restorative space, an increase was not indicated for this patient. However, the maxillary crown length could be adjusted by repositioning the mandibular incisal position. This could be accomplished through a combination of periodontal crown lengthening, endodontic therapy, and prosthodontic preparation of the teeth to create the required space for the upper teeth. Additional possible therapies would include orthodontic intrusion, orthognathic surgery, or extraction.
Cast modifications and diagnostic waxing were valuable tools used in evaluating the possible treatment options outlined above. For this patient, the first step was to establish an ideal maxillary incisal edge position with a pleasing tooth form and gingival interface. Next, the mandibular incisal edge position was established. A corrected occlusal plane was then created with cast surgery and diagnostic waxing. At this point, the diagnostic work-up revealed that the projected position of the mandibular incisors could not be accomplished with endodontics and periodontal crown lengthening at the proposed occlusal plane. This is extremely valuable information to have prior to beginning any treatment on the patient.

Since a chief goal of the patient was limited treatment time, orthodontic therapy, orthognathic surgery, retention of the mandibular teeth with adjunctive endodontics, and periodontal surgery were eliminated as treatment alternatives. Further diagnostic work was then centered on developing a treatment plan utilizing extraction of the remaining mandibular teeth, alveolar reduction in preparation for immediate implant placement, and temporary restoration (Table 1). To organize all the data obtained from the records, the data was formatted in the Parameters of Care for Partial Edentulism by the American College of Prosthodontists2 (Table 2).

Figure 14. One week post operatively.	Figure 15. Final restorations: anterior view at maximum intercuspation.
Figure 16. Right-lateral view of final restorations.	Figure 17. Left-lateral view of final restorations.
Figure 18. Occlusal view of the mandibular final restoration.	Figure 19. Postoperative panoramic radiograph.

Figure 20. Final, full-face smile.

The therapeutic goals were as follows: to aesthetically restore the maxillary anterior teeth to function; to replace the posterior mandibular teeth while restoring function and correcting the occlusal plane; to increase the ability to chew a normal diet; to create an oral environment that minimizes the need for further future restorative care; and to facilitate the ease of oral hygiene procedures.

RISKS, PERFORMANCE ASSESSMENT CRITERIA, AND STANDARD OF CARE

PRESENTING THE TREATMENT PLAN TO THE PATIENT

TREATMENT BEGINS: SEQUENCING

PLACEMENT OF FINAL RESTORATIONS: SEQUENCING

At 12 weeks following the surgery, final restorations were accomplished on teeth Nos. 5 to 14 along with the final mandibular restoration. At 16 weeks after sinus grafting, the right maxillary posterior implants were placed in a single-stage protocol. Six months later, final prosthodontic restoration of the right maxillary implants was completed according to the treatment plan. The patient was given a detailed post-treatment maintenance schedule.

SUMMARY

This patient’s treatment involved a complex diagnostic challenge, as well as a challenging clinical sequence due to the utilization of immediate implant placement and restoration after extraction along with immediate prosthodontic restoration with sinus elevation with bone grafting. The inability to have diagnostic patient wax try-ins required a detailed and exacting diagnostic work-up which included significant laboratory diagnostic wax-ups. The utilization of the ACP Parameters of Care for Partial Edentulism for a PDI Class IV patient provided a framework in which care could be planned and executed with confidence. The availability of various reconstructive materials and techniques to create a seamless restorative result is essential to the success of this type of advanced treatment.

References

Dr. McGarry received his DDS degree in 1975 from UMKC School of Dentistry. He was awarded his certificate in prosthodontics in 1978 from the Veterans Administration Hospital in San Francisco, CA, and became a Diplomate of the American Board of Prosthodontics in 1991. He is a Fellow in the American College of Prosthodontists and has served as president of the College. He currently holds an appointment as an associate professor at the University of Oklahoma School of Dentistry, and is also an adjunct assistant professor at the University of Illinois School of Dentistry. He maintains a full-time private practice limited to prosthodontics and is the clinical director for the McGarry Implant Institute. He can be reached at mcgarry@implantassociates.net or (405) 755-7777.

Disclosure: Dr. McGarry has no financial interest in any of the companies mentioned in this article.

DENTIN HYPERSENSITIVITY DEFINED

One of the reasons your patients may not acknowledge that they are suffering from dentin hypersensitivity is because the discomfort can vary from time to time and season to season. Defined as a short, sharp pain arising from exposed dentin, dentin hypersensitivity typically is triggered by a stimulus that is thermal, evaporative, tactile, osmotic, or chemical in nature, and cannot be ascribed to any other defect or pathology.¹

Dentin hypersensitivity is most commonly explained by the hydrodynamic theory, which demonstrates that fluid within the dentinal tubules can flow in either an inward or outward direction depending on conditions surrounding the teeth. A stimulus that affects the open tubules of the dentin surface causes a fluid movement, resulting in pain. Common stimuli include foods and beverages that are hot, cold, sweet, or sour. Cold air also is a common stimulus. The buccal cervical zones of canine and premolar teeth are the sites most susceptible to sensitivity.

PREVALENCE OF DENTIN HYPERSENSITIVITY

Dentin hypersensitivity is a condition that affects a wide spectrum of patients. The statistics below demonstrate the pervasiveness of this common condition. Varying data exist regarding the worldwide occurrence of dentin hypersensitivity. Clinical findings demonstrate, however, that approximately 1 in 5 people in the United States suffer from the condition.² Although sensitivity affects people of all ages, those between the ages of 25 and 50 are more commonly affected,³ and the condition is slightly more prevalent in women.⁴ In the United States, periodontal patients experience sensitivity at very high rates,⁵ and patients undergoing professional tooth whitening also are especially prone to tooth sensitivity. In fact, 55% to 75% of patients suffer from whitening-related sensitivity.⁶

Clearly, dentin hypersensitivity is more prevalent than dental professionals may realize. Data show that 42% of patients do not report consulting their dentist about their condition, and only 27% of those suffering report using a desensitizing dentifrice to help manage the condition.⁷ Instead, many patients modify everyday behaviors to avoid sensitivity, and may not even be aware they are doing so. For example, some patients avoid hot or cold foods or beverages. Others may avoid brushing sensitive areas, placing them at risk for plaque buildup, calculus formation, and even gingivitis.

DIAGNOSING DENTIN HYPERSENSITIVITY

Making the proper diagnosis is the first step in assisting your patients suffering from dentin hypersensitivity. Identifying patients who are sufferers can be achieved through close examination of existing conditions and by careful analysis of patient behaviors.

In addition to periodontal patients and those undergoing professional tooth-whitening procedures, other groups at risk for dentin hypersensitivity include those who exhibit gingival recession due to aggressive oral hygiene habits, consumers of high-acid food and drink, patients with parafunctional habits, and patients suffering from xerostomia.

In addition to paying special attention to these circumstances, a comprehensive and thorough examination is necessary to diagnose dentin hypersensitivity. Care must be taken to exclude other conditions such as  dental caries, pulpitis, cracked tooth syndrome, marginal leakage, fractured restoration, and restoration polymerization shrinkage.

EFFECTIVE TREATMENT

Addressing any underlying causes of dentin hypersensitivity is the first step in successfully managing the condition. Educating patients about proper oral hygiene habits as well as the potential effects that highly acidic foods and beverages can have on their teeth can help them become aware of practices that may be adding to their sensitivity.

Once underlying causes are addressed, the next course of action is to determine the most effective course of treatment. Treatment options include both in-office procedures and at-home care. It is the intent of this article to expand upon the current home therapies available to our patients.

Generally, the least invasive treatment method should be considered first. Anti-hypersensitivity dentifrices that contain 5% potassium nitrate, such as Sensodyne (GlaxoSmithKline), Colgate Sensitive Plus Whitening (Colgate-Palmolive), and Crest Sensitivity Protection (Procter and Gamble), are easy to obtain and use, and have been proven effective in relieving dentin hypersensitivity. Clinical trials demonstrate a reduction in symptoms in 2 weeks when the dentifrice is used twice daily.⁷ When toothpastes contain potassium nitrate at a concentration of 5%, potassium ions can penetrate the length of the dentinal tubule and block repolarization of the nerve fiber, relieving patients’ pain. Increasing the extracellular potassium ion concentration has been shown to depolarize the nerve fiber membranes, rendering them unable to repolarize because of the remaining high levels of extracellular potassium ions.

The referenced pastes for years have been proven effective in treating the symptoms of dentin sensitivity. Yet new at-home therapies have become quite effective in both decreasing sensitivity and remineralizing the open dentinal tubules. Two such therapies are SoothRx (Omnii Pharmaceuticals) and MI Paste (GC America). These products are delivered via different methods, but their results are based on dentin remineralization.

SoothRx utilizes calcium sodium phosphosilicate as its active ingredient and is distributed from the dental office. Instructions for use are twice-a-day brushing for 2 weeks followed by once-a-week use with routine brushing. MI Paste utilizes Recaldent and is also distributed from the office. A set of custom trays are fabricated, and a variety of treatments can be used with this system. In addition to treating sensitivity, this product has been recommended for use in treating xerostomia, increased caries activity, and enamel and dentin demineralization. Both products work via the route of increasing calcium, phosphate, and fluoride uptake and remineralization.

Should a more immediate approach to treatment be needed, in-office treatments include the application of various desensitizing agents that either occlude the open tubules or inactivate the nerve. In addition, restorations may be placed to cover exposed dentin.  In cases of irreversible pulpitis, patients may require removal of the pulp and root canal therapy, or even extraction of the tooth.

BLEACHING-INDUCED TOOTH SENSITIVITY

Tooth sensitivity is the most common side effect of both professionally dispensed and over-the-counter (OTC) tooth-whitening regimens. In many cases, bleaching-induced sensitivity is so severe patients may interrupt or even stop their treatment. As many as 41% of dentists recommend that their patients discontinue bleaching treatment to relieve their pain.² These considerations may have an impact on overall patient satisfaction.

Dental professionals can address bleaching-induced sensitivity before it becomes a problem by recommending that patients use an anti-hypersensitivity toothpaste for 2 weeks prior to beginning a professional whitening procedure and during the treatment. A recent study of patients using a tray-applied tooth-whitening system demonstrated that patients who brushed with Sensodyne Fresh Mint Toothpaste (GlaxoSmith

Kline) 2 times daily 2 weeks before and 2 weeks during professional whitening treatment experienced significantly more sensitivity-free days as compared to a control group using regular toothpaste.⁸  In addition, study results showed that the proportion of patients who developed tooth sensitivity during the first 3 days of bleaching while brushing with Sensodyne was significantly less than those using the control toothpaste.  From the study data, the desensitizing toothpaste did not adversely affect whitening results.

INCREASING PATIENT SATISFACTION

Patients using the anti-hypersensitivity toothpaste in the above study also reported they were significantly more satisfied with their tooth-whitening treatment and would be much more likely to repeat treatment in the future. Patients also reported no inconvenience in changing toothpastes.

Recommending that patients use an anti-hypersensitivity toothpaste containing 5% potassium nitrate for 2 weeks prior to and 2 weeks during professional bleaching treatment can help make your patients more comfortable and more satisfied with their bleaching treatment. This protocol can help reduce the potential for interruption or discontinuation of treatment due to whitening-induced tooth sensitivity. Patients who complete their treatment comfortably and on time also may be more likely to recommend professional whitening treatment to others,²  further increasing patient referrals.

CONCLUSION

As discussed in this article, dentin hypersensitivity is more prevalent than both patients and dental professionals may recognize. This common condition affects nearly 20% of adults in the United States. Its complex etiology and symptoms, however, can make diagnosis difficult. A number of factors, including professional whitening treatments, can increase a patient’s potential for tooth sensitivity. Fortunately, anti-hypersensitivity toothpastes are a safe and effective way to treat dentin hypersensitivity, and  patients undergoing professional whitening treatment can use them to make the bleaching procedure more comfortable. Addressing whitening-induced sensitivity before patients begin treatment can positively impact patient satisfaction and increase opportunity for profit.

References

1. Holland GR, Narhi MN, Addy M, et al. Guidelines for the design and conduct of clinical trials on dentine hypersensitivity. J Clin Periodontol. 1997;24:808-813.

2. Data on file, GlaxoSmithKline.

3. Gillam DG, Aris A, Bulman JS, et al. Dentine hypersensitivity in subjects recruited for clinical trials: clinical evaluation, prevalence and intraoral distribution. J Oral Rehabil. 2002;29:226-231.

4. Addy M. Dentine hypersensitivity: new perspectives on an old problem. Int Dent J. 2002;52:367-375.

5. Taani DQ, Awartani F. Prevalence and distribution of dentin hypersensitivity and plaque in a dental hospital population. Quintessence Int. 2001;32:372-376.

6. Haywood VB. Contemporary Esthetics and Restorative Practice. 1993;3(suppl):2-11.

7. Fisher SW, Tavss EA, Gambogi RJ, et al. Anticaries efficacy of a new dentifrice for hypersensitivity. Am J Dent. 2003;16:219-222.

8. Haywood VB, Cordero R, Wright K, et al. Brushing with a potassium nitrate dentifrice to reduce bleaching sensitivity. J Clin Dent. 2005;16:17-22.

Dr. Graham is extensively involved in lecturing and continuing education, focusing on incorporating current clinical advancements through “conservative dentistry.” He is the co-founder of Dental Team Concepts, a continuing education company whose philosophy and programs use contemporary, interactive formats to integrate time-proven conservative dentistry with 21st century materials and techniques. His courses emphasize diagnosis, evidence-based treatment, dental materials, adhesion and cosmetic dentistry, customized approaches to periodontal care, implants, and laser dentistry. He is in private practice in Chicago and holds a part-time faculty position at the University of Chicago. He can be reached at (773) 684-5702 or lgrahamdds@ aol.com.

Ask yourself these questions. How many times a week does one of your patients show up with a fractured tooth? Why did the tooth fracture? Could you have prevented it or was it an accident? On average, does a fractured tooth require more or less treatment than a simple filling replacement?

Let me begin with 2 statements: Healthy teeth rarely fracture. Most cusp fractures are due to undiagnosed recurrent decay.

THE PROBLEM OF RECURRENT DECAY

Recurrent decay is one of the biggest problems facing the profession today. It is a problem because it is not being diagnosed, and patients are paying the price for our improper diagnoses. Recurrent decay is one reason a patient can go to 2 different dentists and be told by one that everything looks fine, while another thinks that the patient should have most of his or her fillings replaced. Who should the patient believe? When should existing dental restorations be replaced? What are the criteria we as dentists should follow? Unless we as a profession come to terms with this problem, we will face increasing distrust as the opinion of one dentist is contradicted by the next. The patient will believe the dentist who says what he or she wants to hear, regardless of whether the diagnosis is correct. Our regulatory agencies are getting concerned. They tend to encourage the “fix it when it’s broken” philosophy. Where is the evidence? Show us the x-rays! What are we as general practitioners to do? What should we believe?

It is the intent of this article to shake things up a bit…to cause you to go back to your operatory and look again. As Arnold Schwarzenegger once said, Hear me now, but listen to me later.

Let’s review and examine some of our existing paradigms. We know that primary decay will occur in the weakest points of the enamel shell of a tooth. These are the pits and fissures. We can check these areas clinically with an explorer. The next areas prone to decay are the interproximal areas because the bacteria can sit here, undisturbed, for weeks on end. These areas are best observed on radiographs. Once these areas have initially decayed, it is almost impossible to decay the smooth enamel surfaces that remain, unless the patient’s oral situation changes dramatically.

By definition, recurrent decay occurs around existing restorations, but looking for it using the same tools we use for detecting primary decay is fallacy. Recurrent decay starts internally in the dentin beside the existing restoration. Subsequently, it cannot be probed with an explorer. It begins with the breakdown in the seal between the restoration and the tooth. This is called microleakage. Bacteria wriggle their way in and very slowly begin to decay the tooth from the inside out. Eventually, the decay completely undermines the cusp, which at some point in time will fracture.

The rate of progress of recurrent decay is slow because these bacteria are not very well fed. Not much food leaks in (microleakage). Contrast this to bacteria living in an area of primary decay where there is macroleakage.

SOME COMMON MYTHS

Myth 1: If it is decayed, then we will see it on our radiographs. Unfortunately for us, we most likely will not see the decay on radiographs, and the reason is quite simple. When we look at a radiograph and examine existing restorations, we cannot see what is facial or lingual to the restoration. By the time the decay has spread far enough to show on our radiographs, the cusp will already be fractured. The other reason we can’t see the recurrent decay is that the amount of dentin under the cusps beside the restoration is fairly small, and even if totally decayed, the radiographic change will be minimal. Remember that 40% of the structure must physically not be there in order for it not to show radiographically.

Myth 2: We will be able to see the margins of the restoration breaking down before it begins to decay. This also is usually untrue. We are trying to seal out bacteria that are approximately 0.8m in size. The smallest gap that we can see reliably is about 50 m, and this is about half the size of clinically acceptable crown margins. The point is that it is impossible to determine visually when the marginal seal has broken down enough to allow bacteria in.

Myth 3: Teeth fracture because they are weakened by an amalgam restoration. In some cases this is true. But a truly weakened tooth will not survive any length of time under the incredible loads of mastication. So, how is it that the tooth has been functioning just fine for 10 or more years and only now has fractured? If it was truly so weak, it should have broken years ago. The real reason the tooth has fractured off a cusp is because it was decaying inside out, slowly, for years. I know what you’re thinking. There is no evidence of decay just nice shiny dentin. Rarely do we get to see the fractured piece, but when we do examine it closely we will find that the supporting dentin was decayed and the tooth fractured off the weakened part. Nice healthy dentin will rarely fracture.

Myth 4: We need to crown that tooth because it could fracture at any time, and we don’t know how deep it will fracture, and you might lose the tooth. The truth is, for the most part teeth fracture very predictably, as mentioned above. Only endodontically treated teeth split in half, and this is because the whole core of the tooth has been removed. This truly is a weak tooth and requires full coverage. All other teeth will fracture a cusp starting at the base of the restoration and proceeding until sound dentin is found, and this will only happen if there is recurrent decay or trauma.

Myth 5: The patient will experience pain or discomfort if there is decay. Recurrent decay forms just under the enamel beside the restoration. The pulp is located far away under the restoration. The recurrent decay would have to be very advanced to cause discomfort. Usually by this time the cusp will have fractured off.

HOW TO DETECT RECURRENT DECAY

Recurrent decay can be detected by looking for the subtle changes occurring in the coloration of the enamel surrounding the restoration. Enamel is like opaque glass. You can’t see what’s on the other side, but you can see if it is brown or black. For the most part, darkened enamel around a restoration is an indicator of recurrent decay occurring under the cusp. In the case of an amalgam restoration, we know that you cannot severely undercut enamel cusps and fill with amalgam. This is why thin cusps need to be shoed when using amalgam. So, when we examine the tooth from the occlusal we know that the amalgam restoration extends almost straight down. Severe undercuts are not allowed. Therefore, how is it possible to think that the black or brown enamel beside the restoration is amalgam shining through? What you are looking at is recurrent decay through a frosted window (enamel). Recurrent decay will not generally start along the whole occlusal margin. So, you will see that the enamel is discolored in one area but not in others.

Another telltale sign is small cracks forming in the enamel, especially if they are in a discolored area. Enamel is much like glass hard but brittle. Place glass on a solid smooth floor and you could jump on it and it won’t break. This is analogous to enamel supported by healthy dentin. Place the same glass on a pillow and it will crack. Enamel that is cracking in the presence of discoloration is enamel supported by decayed dentin.

CRITERIA FOR REPLACEMENT OF A RESTORATION

When is the best time to replace a restoration? Should we wait until the tooth is broken? Should overt, obvious, primary decay be present? Should the patient be in pain? Unfortunately, these are precisely the only situations where we are told we can intervene. But, by the time these things occur it is too late. More tooth is gone. Costlier procedures must be performed. Now our patient requires a crown or a root canal. Did we do our job to prevent?

Recurrent decay requires a whole new paradigm. A primary restoration should never be placed until we absolutely see decay. However, in a virgin tooth we actually can see the decay. In a previously restored tooth we cannot see the decay, only the signs of it, which are subtle. We must be more alert when examining old restorations in order to spot recurrent decay early and prevent further decay and breakdown.

When is the best time to replace a restoration? At the exact moment the tooth begins to decay again. Then we can replace the restoration and reseal the tooth without having to remove additional tooth structure. Of course, that exact moment is impossible to predict. Reality dictates that we will either be early and not find decay (a crime), or we will be too late and find decay (a worse crime). It is my opinion that being a little early is better than being late. This does not mean that it is open season on all old restorations. We must recognize the signs of breakdown and only when we see them, act appropriately. We cannot afford to be routinely replacing fillings too early because iatrogenic damage to the tooth occurs every time we pick up our drills.

So, I have devised a set of criteria specifically for the replacement of existing restorations (Figures 1 throught 9):

Figure 1. Notice darkness on first molar, between restorations on second molar, and on MB of premolar.	Figure 2. Side view.
Figure 3. Fillings removed. Decay present beside old restorations.	Figure 4. Filling out—tooth still dark. Darkness not from black filling but from decay.
Figure 5. Angle view of decay spreading laterally.	Figure 6. Cleaning it up.
Figure 7. Notice how decay undermined cusps. Palatal view.	Figure 8. Notice how decay spread laterally undermining cusp. Buccal view.

Figure 9. Finished composite restorations.

(1) Discolorations in the enamel beside the restoration. Nine out of 10 times it is recurrent decay. But sometimes it’s not. In the case of amalgam, sometimes it actually is the amalgam shining through. Shine-through usually occurs in the interproximal vertical margin area where the enamel is thin. Discolorations viewed from the occlusal are almost always recurrent decay.

(2) Visibly open margins. If you can see open margins, then as previously discussed this is a bacterial freeway. Change the restoration now before it decays. You will still be too late most of the time.

(3) A small area of visible breakdown is enough reason to replace the whole restoration. No amount of decay is acceptable. Do not patch up old fillings. Once you touch your drill to the tooth it belongs to you. If the restoration is decayed in one spot, can you guarantee it isn’t decayed elsewhere? Fix it properly.

(4) Cracks in the enamel beside old restorations, especially if discolored.

(5) Patient complaints of sensitivity to temperature or sweets may indicate microleakage at the very least. These symptoms in addition to any of the above require that the old restoration be replaced.

One of the most useful tools you can have in the dental office is an intraoral camera. Used properly it is a real aid to a proper examination. It is not a fancy toy to show patients their teeth. That is an added bonus. If you use the camera as a microscope and magnify the tooth 40x on the monitor and seriously start to look for the telltale signs of recurrent decay, you will find that there is an epidemic of recurrent decay in progress today. Teeth are not breaking without reason; they are decayed. If you see a lot of broken teeth on your existing patients, then you aren’t looking hard enough. When you remove the restorations, show your patient the decay. Then they will truly understand why you removed a filling from a tooth that was neither broken nor giving them pain.

CONCLUSION

Watch for the signs of recurrent decay and follow up. You will find decay most of the time if you follow the criteria described in this article. Take intraoral photos of the teeth as part of your records. Write down in your clinical notes your diagnosis (recurrent decay/impending cusp fracture/open margins, etc). Build rapport and trust with your patients by showing them the decay as you work. Most of all, remember that we require a good reason to replace an old filling, and if you have one, then it is OK to proceed. An ounce of prevention is worth a pound of cure.

Dr. Arvanitis maintains a full-time dental practice in Waterloo, Ontario, and has taken more than 1,100 hours of continuing education from some of the most renowned masters of cosmetic and implant dentistry. He is a fellow of the Academy of General Dentistry, a fellow of the International Congress of Oral Implantologists, a member of the American Academy of Cosmetic Dentistry, and a member of the American Association of Implant Dentists. He can be reached at (519) 748-2282 or drgeorge@golden.net.