Long-Term Esthetic and Functional Success Following an Initial Treatment Complication

Unexpected restorative failures can and do occur. When they happen, it can lead to a loss of confidence on the part of both the patient and dentist. This article describes how a systematic review and assessment of the biomechanical and functional parameters of a patient after an unexpected complication resulted in a treatment approach that not only maintained patient confidence but also led to a successful esthetic and restorative outcome that has lasted almost 10 years.

In 2005 a 55-year-old man presented with pain on his maxillary left. At the time, he was only concerned with the discomfort in this area. Deep caries and periodontal involvement were discovered on teeth Nos. 16 and 17 and the two offending teeth were successfully treated by extraction (Figure 1).

Six months later, the patient returned with broken facial porcelain on tooth No. 5, a bridge abutment (Figure 2). He indicated that he would like a "better smile" with longer, whiter teeth, and he disliked the "spaces" between his lower anterior teeth (Figure 3). He agreed to a complete examination with a functional and esthetic assessment.

The medical history revealed the use of Aciphex to treat gastroesophageal reflux disease (GERD) and a history of hepatitis A. The patient consumed an acidic diet that included 60 to 80 ounces of coffee daily and spicy hot sauce to flavor his food, and he was unwilling to alter his diet. He had a 25-year history of tobacco use, though he had not used it for the past 10 years. A complete oral cancer examination that included the use of a VELscope^® device¹ (Velscope, velscope.com) revealed no abnormalities.

The patient reported routinely biting his lips and tongue while eating, often hard enough to cause bleeding, and that food would become trapped under his bridges and in the embrasure spaces between his lower front teeth. Further, the patient noted that these spaces had developed recently and the anterior teeth had become shorter. Jaw muscle soreness due to clenching was also common.

Periodontal: Generalized mild horizontal bone loss was noted with pocket depths of 2 mm to 4 mm. Tooth No. 30 had a 5-mm pocket on the distal. Tooth No. 3 had facial recession, with site-specific attachment loss. Teeth Nos. 20 and 29 had been extracted when the patient was a teenager, with subsequent alveolar ridge atrophy. There was no mobility. The diagnosis was mild periodontitis, AAP type II.

Risk: Low
Prognosis: Overall good; fair for teeth Nos. 3 and 30

Biomechanical: Recurrent caries was noted on teeth Nos. 3, 19, and 30. The dentition exhibited significant cupping,² with more than 2 mm of attrition and active erosion. Teeth Nos. 6 through 12 had moderate cupping (Figure 4), and mild cupping was noted on teeth Nos. 22 though 27. Teeth Nos. 3, 5, 13, 14, 18 through 20, and 28 through 31 were structurally compromised due to caries or the size of existing questionable restorations.

Risk: High
Prognosis: Generally poor; hopeless for teeth Nos. 3, 19, and 30 due to the presence of caries

Functional: The patient reported a clenching habit, soreness of masseter muscles, lower anterior teeth spaces, and a decrease in tooth height in his upper and lower anterior teeth over the previous 5 years. These were all factors that increased his functional risk. Additionally, a nightguard that he wore showed wear facets in an anterior-posterior direction. The temporomandibular joint, range of motion, and muscle examinations were normal, except for bilateral soreness to palpation in the masseter muscles. The non-restored anterior teeth had severe attrition. Wear facets were noted on the posterior teeth. The diagnosis was occlusal dysfunction and potential parafunctional habits.

Risk: High
Prognosis: Poor, due to the active nature of the functional problem, the presence of severe wear, and evidence of parafunction

Dentofacial: The patient was unhappy with the spacing of teeth Nos. 22 through 27 and desired whiter, longer teeth. The mandibular anterior gingiva was visible when he smiled, although the posterior gingiva was not. There was minimal gingival display on the maxilla, even when smiling widely. He showed no maxillary anterior tooth structure in repose, and 1 mm or less when smiling (Figure 5 and Figure 6). His maxillary central incisors were 6 mm long.

Risk: Moderate
Prognosis: Good for maxilla and mandibular posterior teeth; fair for mandibular anterior teeth

The treatment plan would be as follows: First, a periodontal consult would assess the recession on tooth No. 3, and an implant to replace tooth No. 4 was planned, which would require an osteotome sinus lift. After full-mouth scaling and root planing (SRP), a 4-month periodontal maintenance schedule would be recommended.

Next, feldspathic bonded veneers were planned for teeth Nos. 6 through 12 to minimize the removal of tooth structure. A veneer option for teeth Nos. 22 through 27 was presented to the patient, but he opted for direct composites due to financial considerations.

Core-supported restorations were planned for teeth Nos. 3 through 5, 13, 14, 18, 21, 28, and 31. Fixed partial dentures (FPDs) would be placed for teeth Nos. 19 through 21 and 28 through 30, using ovate pontics to minimize food trapping. Implant placement for teeth Nos. 20 and 29 was rejected because extensive bone grafting would have been necessary to place implants, and FPDs would adequately achieve the treatment goals.

A Kois deprogrammer^™ (Kois Center, koiscenter.com) would then be used to determine condylar position/centric relation (CR) reference. Lastly, the maxillary teeth would be lengthened to create a pleasing smile. The vertical dimension would be increased and restored in CR.

After the full-mouth SRP, an implant was placed at tooth No. 4, and an acrylic (Jet Tooth Shade^™ Acrylic, Lang Dental Manufacturing, langdental.com) temporary bridge was placed to provide function and esthetics during the integration phase (Figure 7).

The patient was deprogrammed with the Kois deprogrammer.³ The maxillary cast position was transferred to the articulator using the Dento-Facial Analyzer^™ (Panadent, panadent.com) and the models were mounted in CR using a bite registration. The longest tooth in the arch was determined to be tooth No. 5, providing a visual point of reference against the mounting plate to help verify an accurate mounting (Figure 8). A diagnostic wax-up was created to accommodate the desired central incisor length of 10 mm by decreasing the height of the Panadent^™ articulator mounting platform (Panadent) by 2 mm.

A putty stent (Zhermack SpA, zhermack.com) made from the wax-up was used to create a direct chairside "trial smile."⁴ The phonetics, esthetics, and function of the planned changes were acceptable to both the dentist and patient (Figure 9).

The upper right quadrant was prepared first. The deprogrammer was inserted into the mouth and the platform adjusted to reproduce the previously determined new vertical dimension. A reproducible jaw position was confirmed and a bite registration was taken for the quadrant. In the same manner, the upper left and upper anterior segments were prepared. A full-arch polyvinyl siloxane (PVS) impression was taken.

After each segment was prepared, Integrity^® temporaries (Dentsply Sirona, dentsplysirona.com) were made using the stent previously fabricated from the wax-up. While placing posterior temporaries, a direct composite platform was placed lingual to teeth Nos. 8 and 9 to maintain the CR position. The occlusion on each temporary segment was adjusted and evaluated to ensure equal bilateral and simultaneous posterior contacts. The patient was seated upright and asked to chew on 200-µm articulating paper to verify there were no functional interferences in the pathway of the chewing envelope. There were no problems with the temporaries over the 2 months while the laboratory fabricated the restorations.

Eight weeks later, the maxillary restorations were cemented. The veneers for teeth Nos. 6 through 12 were bonded with Bisco One-Step^® adhesive (BISCO, bisco.com) and RelyX^™ Veneer Cement (3M, 3M.com). The remaining restorations were cemented cohesively with RelyX Unicem^™ (3M) after particle abrasion using a PrepStart^™ air abrasion unit (Zest Dental Solutions, zestdent.com) with 27-µm aluminum oxide. The occlusion was checked and refined in both CR and function as described above.

Three weeks after delivery, the veneer on tooth No. 8 broke. The portion attached to the dentin came loose, exposing shiny, sclerotic dentin, while the portion bonded to the enamel surfaces remained intact (Figure 10). Two days later, the veneer on tooth No. 7 chipped. A careful assessment was performed to determine the etiology of the restorative failure so that it could be addressed before replacing all the bonded veneer restorations. The patient revealed that he had developed a habit of chewing his cuticles and fingernails, as well as popsicle sticks. At the time of the veneer breakage, the lower arch had not yet been completed and the patient observed that the upper and lower midlines did not match. He reported "fiddling with" his jaw to line up the midlines by moving his lower jaw to the right. In addition, the anterior teeth had only a thin enamel rim on the lingual and sclerotic dentin on the worn surfaces.

The determination was made that the thin enamel rim and the presence of sclerotic dentin did not provide an adequate bond strength to resist the loads placed on the anterior teeth,⁵ especially during parafunctional habits. It was also possible that dysfunction had been introduced with the seating of the maxillary restorations.

Parafunction, occlusion, and bond strength all had to be considered as potential causes of failure, because it was not possible to determine only one cause. The broken veneers were temporized with bonded Integrity provisional restorations.

A new Kois deprogrammer was fitted to the new maxillary restoration contours to maintain CR position during treatment of the mandibular teeth. The lower posterior teeth were prepared for the planned restorations, temporaries were placed, and a PVS impression was taken. To accommodate the patient's travel schedule and to ensure that the temporaries functioned without problems, the patient returned for cementation 12 weeks after the preparation appointment. He reported having no problems while wearing the temporaries. The mandibular posterior restorations were cemented using the protocols described above for cohesively retained restorations. Per the treatment plan, the vertical dimension was increased when the lower posterior restorations were fabricated to allow adequate space for the chewing envelope once the lower incisors were lengthened.

A silicone matrix of the diagnostic wax-up was used as a template to restore the lower anterior length with composite resin on teeth Nos. 22 through 27. The teeth were micro-abraded using 27-µm aluminum oxide with the PrepStart unit, then etched with 37% phosphoric acid. The teeth were then bonded with Clearfil SE Bond^™ (Kuraray, kuraray.com), and shade B1B composite (Filtek^™ Supreme, 3M) was placed. The restorations were smoothed and polished, and the occlusion and functional pathway were confirmed for accuracy.

One month after the lower arch was completed, the patient returned for the restoration of teeth Nos. 6 through 12 with lithium-disilicate crowns (e.max^®, Ivoclar Vivadent, ivoclarvivodent.com). Cohesively retained crowns were selected due to concerns that the thin enamel rim on the lingual and sclerotic dentin may have resulted in a weaker bond strength and contributed to restoration failure.

Teeth Nos. 6 through 12 were prepared and temporized, and impressions were taken using the protocols previously described. Four weeks later, the crowns were cemented following the previously described protocols. The occlusion was carefully checked and refined using the Kois deprogrammer, occlusal marking paper (Accufilm^™, Parkell Inc, parkell.com), shimstock (Almore International, Inc, almore.com), and 200-µm articulating paper (Bausch, bauschpaper.com) to ensure that the chewing envelope was not constricted with the new restorations.

A treatment plan developed for this patient today would differ from the one created in 2006. With his history of parafunction and GERD, he would be referred for a sleep evaluation.⁶ Conservative cohesive restorations would be planned for teeth Nos. 6 through 12, and a nightguard would have been prescribed to wear until the mandibular arch could be restored.

After completion of treatment, the periodontal risk remained low with a good prognosis. The biomechanical risk was lowered to moderate, with a fair prognosis. This was achieved by removal of decay and placement of crowns on teeth Nos. 3 and 5. Although teeth Nos. 6 through 12 did have tooth structure removed for the placement of the crowns, the teeth were prepared conservatively, and the exposed dentin was covered to prevent further erosion. While the functional risk remains high due to the presence of parafunction, once the dysfunction was treated and the parafunction recognized, the functional prognosis could be improved to "fair."

The patient continues to wear a nightguard and reports no muscle soreness or functional concerns. His overall dentofacial risk remains moderate due to the tissue display on the lower anteriors, with a good prognosis.

Almost 10 years after requesting an improved smile, the patient remains pleased with the esthetic result, and no further clinical complications have arisen (Figure 11 through Figure 15). The restoration failure that occurred soon after delivery could have discouraged both the patient and the practitioner; however, a careful, objective evaluation of all possible causes for the failure paved the way for long-term successful treatment. Once treatment was completed for both arches, the patient no longer reported any biting of the lips or tongue while eating or jaw soreness due to clenching.

Sheila Naik, DDS
Private Practice
Glendale, Arizona
Clinical Instructor
Kois Center
Seattle, Washington