Splinted Porcelain Laminate Veneers With a Natural Tooth Pontic: A Provisional Approach for Conservative and Esthetic Treatment of a Challenging Case
Esthetic rehabilitation of discolored anterior teeth is always a great challenge, especially in the presence of pathology. Fortunately, conservative management in the esthetic zone has become more feasible in compromised cases because of the development of restorative materials and advances in dental adhesives. This report presents a complicated case of a patient with tetracycline-related discoloration, multiple root resorption, and a periapical lesion. Treatment was conservative and used a natural tooth pontic and splinted porcelain laminate veneers.SUMMARY
INTRODUCTION
Minimally invasive treatment is undoubtedly the most valuable approach to increasing the longevity of natural teeth in esthetic restorations. The conservative approach in esthetic restorations is gaining popularity due to the development of restorative dental materials such as adhesives, resin composites, and porcelain. There is accumulating evidence of their durable bonding effectiveness from laboratory and clinical studies.1-3 These advancements in adhesive dentistry enable clinicians to have various treatment options for a diversity of esthetic problems.
Tooth discoloration results from extrinsic or intrinsic factors.4 Intrinsic discoloration generally arises from chromogens that chelate to the tooth structure and are often of systemic or pulpal origin, and the management of intrinsic discoloration is usually unpredictable.5,6 Tetracycline (TC) staining is a typical intrinsic discoloration that rarely responds to bleaching treatment and is most effectively addressed with restorative procedures to mask the dark color.7 Porcelain laminate veneers have been proposed as a viable restorative option for TC-stained teeth to conceal the color defect without extensive tooth reduction.8-11
Coexisting periapical lesions or periodontal problems of anterior teeth needing esthetic restoration may require a multidisciplinary approach and/or modification of the conventional treatment plan. Even when an abutment is periodontally compromised, it can still be used as a natural tooth pontic within a splinted crown restoration as it offers the benefits of being the right size, shape, and color.12,13 The aim of this report is to present a provisional approach developed to address our patient's strong demand to retain a natural tooth while still achieving esthetic results in the presence of diverse esthetic and pathologic problems with the maxillary anterior teeth.
CASE REPORT
A 36-year-old woman presented with a chief complaint of recurring fistula of her left maxillary central incisor and desired esthetic rehabilitation of her anterior maxillary teeth. A clinical examination showed a generalized band-like grayish TC stain of the anterior teeth. Tooth #9 had a darker discoloration in the cervical area than the other anterior teeth. The tooth was tender to percussion, and a labial sinus tract was observed in the apical area. Unesthetic old resin composite restorations also existed on the mesial side of both canines. The patient had a slightly open bite with deep overjet, and anterior guidance was absent in protrusive movement. A lingual bonded retainer was observed in both the maxillary and mandibular anterior teeth. Radiographic examination revealed general root resorption in most of the teeth and severe root resorption in some incisors. Tooth #9 had a radiolucent apical lesion with an excessively shortened root (Figure 1). The patient's dental history indicated that orthodontic treatment for her open bite was completed a year previous to the examination, and a root canal treatment was performed on tooth #9 six months previous due to pain. The patient was four months post nightguard bleaching treatment to remove the discoloration on her upper anterior teeth, which was not effective in lightening the teeth.
Citation: Operative Dentistry 40, 6; 10.2341/15-020-S
The patient had a strong desire to save tooth #9 rather than have it extracted, even though she was well aware of the severe root resorption. Her treatment plan was thoroughly discussed, and intentional replantation was planned to maintain tooth #9 using a “natural tooth pontic concept.” To manage the apparent TC discoloration on tooth #9, nonvital bleaching was performed prior to replantation. Splinted porcelain laminate veneers, as provisional restorations, were designed for teeth #8, #9, and #10 with consideration for the patient's occlusion and reinforcement splinting of the natural tooth pontic.
Tooth #9 was atraumatically extracted using flat-beak forceps to minimize damage to the periodontal tissues after repositioning guidelines were marked on teeth #8, #9, and #10 using a marking pen. The extraction socket was thoroughly debrided and degranulated. Granulation tissues and resorptive lesions of the tooth were removed using a periodontal curette and an ultrafine diamond point (Komet, Lemgo, Germany), and the apex was prepared for retrograde filling. The apical preparation was etched with 37% phosphoric acid, and a two-step etch-and-rinse dentin adhesive system was applied (Adper Single Bond 2, 3M ESPE, St Paul, MN, USA). The adhesive application area was carefully limited to just around the prepared canal to ensure there was no spillage out onto the root surface. The canal was then filled with flowable resin composite (Tetric N Flow, Ivoclar Vivadent, Schaan, Liechtenstein) that was subsequently light cured. The tooth was repositioned along the marked guidelines and splinted to the adjacent teeth using adhesives and resin composite (Adper Single Bond and Z-250, 3M ESPE). A prefabricated lingual retainer was placed to retain alignment of the anterior teeth (Figure 2). To improve the dark gray-brown discoloration of tooth #9, nonvital tooth bleaching was performed two weeks after surgery with sodium perborate and distilled water (Figure 3). After bleaching, the access cavity was filled using adhesive and resin composite (Adper Single Bond and Z-250, 3M ESPE).
Citation: Operative Dentistry 40, 6; 10.2341/15-020-S
Citation: Operative Dentistry 40, 6; 10.2341/15-020-S
Before tooth preparation for laminate veneers, a diagnostic wax-up was performed on a study model to assess the incisal interference and fabricate a silicone index as a preparation guide. Intraoral mockup with resin composite was also performed to simulate the shape of the final restorations (Figure 4). Six maxillary anterior teeth were prepared for porcelain laminate veneers with an incisal overlapping design. Labial reduction was performed with the dimensions of 0.5, 0.9, and 0.9 mm in each cervical, middle, and incisal third of the teeth, respectively, which is deeper than a standard laminate veneer case.14,15 Preparation depth was checked using a depth gauge bur (Komet) and the silicone index (Figure 5A,B). Predesigned proximal preparation was carefully performed with consideration for the tooth #9 splint and the overall esthetic results. The interproximal margins between the canine and lateral incisor were extended to be at the linguoproximal line angle because the natural contact was already lost by removing the old resin composite restorations. The proximal extension in the embrasure between #7 and #8 and the distal embrasures of the canines was prepared just short of breaking the contact area. To provide a natural embrasure appearance in the splinted laminate veneers, the interproximal margins between teeth #8 and #9 and between teeth #9 and #10 were further lingually extended into two thirds of the proximal surface, which had been splinted with resin composite. An estimated 0.5-1.0 mm of the incisal edge was reduced to create a butt joint with the palatal surface because we wanted to increase the incisal length 1.0-1.5 mm from the existing crown length, assuming a 1.5- to 2.0-mm incisal porcelain length in the final restorations to address the openbite. The gingival margin was prepared with a fine diamond chamfer bur to be positioned 0.5 mm subgingivally.
Citation: Operative Dentistry 40, 6; 10.2341/15-020-S
Citation: Operative Dentistry 40, 6; 10.2341/15-020-S
A final impression was taken (Exafine, GC Corporation, Tokyo, Japan), and provisional restorations (Luxatemp, DMG, Hamburg, Germany) were placed using noneuginol temporary cement (Figure 5C,D). Opaque lithium disilicate (IPS e.max Press LT, low translucency, shade BL3, Ivoclar Vivadent) was chosen as a porcelain ingot to mask the intrinsic discoloration with thin veneering material. The laminate veneers on teeth #8, #9, and #10 were splinted considering the unfavorable crown to root (C/R) ratio of tooth #9 and the occlusion that showed no anterior guidance on protrusive movement (Figure 6A).
Citation: Operative Dentistry 40, 6; 10.2341/15-020-S
After try-in, the internal surfaces were conditioned with 5% hydrofluoric acid (IPS ceramic etching gel, Ivoclar Vivadent) for 20 seconds, rinsed with water, and dried. Then, silane coupling agent (Monobond S, Ivoclar Vivadent) was applied for one minute and dried. The prepared teeth were etched with 37% phosphoric acid for 15 seconds, rinsed, dried, and adhesive applied (Scotchbond Multi-Purpose, 3M ESPE). Transparent shade Variolink N resin cement (Ivoclar Vivadent) was applied as a luting agent. Excess cement was gently removed using an explorer and pre-engaged floss after tack-curing for 1-2 seconds with a light emitting diode (LED) light curing device (Bluephase 20i, Ivoclar Vivadent). Multidirectional final light curing was done for 60 seconds each. Finishing and polishing was performed with a 24-fluted carbide bur and ultrafine diamond bur (Komet).
Occlusion was checked in protrusive and lateral movements and revealed the absence of incisal contact, which was the same as before treatment (Figure 6B). The patient was very satisfied with her esthetic outcome after delivery of the final restorations (Figure 6C,D). At her one-year follow-up visit, the restorations had still maintained their esthetic appearance, and a stable periodontal tissue response was noted (Figure 6E,F).
DISCUSSION
Treatment planning decisions should be based not only on comprehensive examination and diagnosis but also an understanding of the therapeutic indications and possible complications.16 Thus, therapeutic modalities, knowledge of restorative materials, and patient desires should be incorporated in decision-making to ensure a satisfactory treatment outcome. In the present case, treatment decisions were made using a systematic approach to resolve several clinical problems that were primarily due to periapical inflammation of tooth #9 with an unfavorable C/R ratio and generalized TC discoloration. Specifically, various clinical problems and the patient's strong desire to save a natural tooth led us to design splinted laminate veneers with a natural tooth pontic that might serve as a temporary restorative treatment.
Decision #01: Preserve or Extract the Compromised Tooth
The first decision with regard to resolving the periapical inflammation of tooth #9 was between extraction and surgical endodontic treatment. Because of the drastic root resorption that resulted in the unfavorable C/R ratio, extraction would have been a rather rational treatment option. The first option after tooth extraction was implant installation at the extraction site, and the second was placement of a three-unit fixed partial denture on teeth #8-#10. However, both options were rejected because the patient had a strong desire to save tooth #9, even though she recognized that saving the compromised tooth could lead to a provisional restorative treatment. On the other hand, preserving the natural tooth was advantageous not only for avoidance of psychologic trauma, but also for more predictable conservation of the hard and soft tissue around the anterior maxillary teeth compared with extraction.17-19 The behavior of the alveolar bone after extraction complicates routine implant installation procedures and esthetic prosthetic restoration due to the reduced bone volume and gingival degeneration.20 The biotype of the gingiva is thin, particularly in young female patients, and soft tissue recession and black triangle formation is inevitable. By keeping and using the natural tooth as a pontic, the cervical gingival contour could easily be maintained without noticeable gingival recession and shrinkage.
An apicoectomy or intentional replantation was considered to save tooth #9, but apicoectomy was ruled out due to the short length of the root and limited access to the extensive resorptive lesion. We adopted the natural tooth pontic concept for the treated tooth by replantation. Surgical curettage and replantation also enabled an extraoral radical operation to remove the periapical inflammation and external root resorption.
Decision #02: Management of the TC Discoloration of the Maxillary Anterior Teeth
Because of the severity of the discoloration, TC-stained teeth may discourage any attempt to improve the shade disharmony using bleaching agents, which usually do not remove all of the grayish and bluish undertones.21,22 Our patient had a typical TC band and reported little effect of a bleaching treatment performed at a previous clinic. Therefore, the restorative options, ie, full veneer or laminate veneer restorations, were remaining options available to manage the discoloration. Full veneer restorations would have a more definitive effect in masking the intrinsic discoloration than laminate veneers and also would allow us to easily correct the tooth shape and alignment: an open bite and excessive overjet in this case. However, they have shortcomings in terms of extensive reduction of tooth structure and the possibility of pulp irritation. In this case, the incisors had very short roots due to orthodontic complications. We instead chose laminate veneer restorations, which result in less destruction of the dentin and subgingival tooth structure.
The choice of laminate veneer restorations required us to consider several aspects in order to obtain shade improvement. First, the much darker discoloration of tooth #9, which was likely due to necrotic tissues or residual endodontic intracanal medicaments, needed to be removed to lessen the color difference reflected through the laminate veneers; the one-week nonvital bleaching removed the darker discoloration in the cervical area remarkably. With regard to the consideration of tooth preparations, a little more labial reduction was required to allow additional thickness for the ceramic veneers, which may have increased masking ability.14,23,24 We also placed the gingival finishing line 0.5 mm subgingivally to avoid mismatching the shade of the porcelain and dark cervical tooth structure.15 In addition, a high-value opaque lithium disilicate ingot (IPS e.max Press LT, Ivoclar Vivadent) was selected to mask the grayish discoloration effectively.24-27
Decision #03: Maintaining the Tooth That Had Poor Periodontal Support
Even though it was decided that tooth #9 be retained, it was a great challenge given its poor periodontal support due to the very short root and subsequent surgical treatment. Splinting was required because the replanted tooth was regarded as a natural tooth pontic. Splinted restorations are often indicated for functional and esthetic rehabilitation in the setting of periodontally compromised dentition.28 Splint crown restorations have also proven to be effective for stabilizing teeth and ensuring periodontal health.29,30 In the present case, the resin splinting of teeth #8 and #10 and application of the lingual bonded retainer just after intentional replantation played a role in splinting tooth #9. Under normal occlusal conditions, there might not be a way to splint the tooth other than these two methods, even though preparations and placement of each laminate veneer would weaken the proximal resin splinting of tooth #9. However, our patient had excessive overjet and slight open vertical overlap, resulting in absent incisal contact in centric occlusion and protrusive movement. Therefore, we decided to reinforce the splinting of the replanted tooth using a splint laminate veneer, which is an exceptional restorative option. Under our patient's specific occlusion, the splint laminate veneer was believed to provide stability by splinting the tooth and minimizing the possibility of incidental failure associated with using only resin composite and wire.
The IPS e.max Press (Ivoclar Vivadent) used in this case is a reinforced lithium disilicate system with substantially improved physical properties including 400 MPa of flexural strength and greater esthetic characteristics with high translucency compared with other ceramic materials.31,32 The minimally invasive treatment concept used in the present case was possible because of this improved dental porcelain and numerous reports of success in terms of the durability of bonded porcelain veneers.33-36 The splint porcelain laminate veneer in this case provided more bulk in the splinted embrasures by slightly more tooth reduction in the corresponding embrasures of tooth #9, although literature supporting a standard splinting thickness could not be found. The proximal margins of the splinted embrasures were also placed more lingually to give a natural embrasure appearance.
Even though the splinted porcelain laminate veneer with a natural tooth pontic showed a very satisfying result on one-year follow-up, it needs to be observed as a temporary restorative treatment, because supporting literature on the expected longevity of this type of restorations was not found.
CONCLUSION
Using a systematic approach during the decision-making process, a comprehensive treatment plan was developed, and satisfactory esthetic results were achieved in the management of this complicated clinical case. Under a specific occlusion profile, which included the absence of incisal contact during central occlusion and protrusive and lateral movements, a splint laminate veneer with a natural tooth pontic was provisionally used as a conservative and esthetic treatment option to address the challenging conditions of the present case without complications from extraction or a full veneer crown. Periodic periodontal care would help to maintain the esthetic outcome and lengthen the service span of the splinted porcelain laminate veneers.
Preoperative clinical and radiographic examinations. (A): Labial fistula on the apex of tooth #9 (arrow). (B and C): Periapical and panoramic radiographs. Note the shortened roots with external resorption on multiple teeth, especially tooth #9. (D and E): Intraoral photographs of protrusive movement showing the deep overjet without anterior guidance.
Intentional replantation of tooth #9. (A and B): Severe apical root resorption. (C): Apical preparation and retrograde filling with resin composite. (D): Periapical radiograph after surgery. (E and F): Replanted tooth #9 was repositioned along the marked guide line and splinted with resin composite.
(A): Before and (B) after nonvital bleaching of tooth #9 with sodium perborate and distilled water.
(A): Preoperative study model. (B): Diagnostic wax-up. (C): Intraoral resin composite mockup.
Tooth preparation and provisionalization for laminate veneers. (A): Frontal view. (B): Occlusal view. The amount of reduction was checked using a silicone index, which was prefabricated from the diagnostic wax-up model. (C and D): Provisional restorations.
(A): Porcelain laminate veneers. The prosthesis for teeth #8, #9, and #10 was splinted. (B): Intraoral photograph after cementation. (C): Pre- and (D) postoperative extraoral photograph. (E): One-year follow-up intraoral photograph and (F) periapical radiograph.
Contributor Notes