Retrofitting a tooth-supported crown with an implant and abutment: clinical report Luis L. off, DDS, MSc, a Elisa Oderich, DDS, MSc, b ntônio Carlos Cardoso, DDS, PhD, c and Pascal Magne, DMD, PhD d Health Sciences Center, Federal University of Santa Catarina (UFSC), Florianópolis, Santa Catarina, razil; University of Southern California, School of Dentistry, Los ngeles, Calif This article presents a treatment option for a fractured maxillary central incisor root as part of an existing complete maxillary rehabilitation. fter the root extraction and immediate implant placement into the extraction socket, an acrylic resin removable partial denture (RPD) was placed. Six months later, a screw-retained provisional restoration was placed to guide the development of soft tissue contours. n impression was made, and a custom abutment was fabricated to conform to the new gingival profile and the intaglio surface of the existing metal ceramic crown. The custom abutment was placed and the preexisting metal ceramic crown was then cemented. (J Prosthet Dent 2010;103:262-266) Despite the various prosthesis repair techniques reported in the literature, it remains a challenge to restore a damaged prosthesis, particularly in the maxillary anterior region. 1 Traditionally, repair techniques range from direct restoration with light-polymerized composite resin to indirect repair with a metal ceramic crown. 2-4 These procedures are intended to preserve a prosthesis that is in good condition and fits well, with the goal of reducing clinical and laboratory time and expense. Further benefits include preserving esthetics and minimizing biologic damage. Fractured roots present a difficult situation, especially in the esthetic zone. 5 The loss of a single tooth in a restored arch increases the complexity of the arch restoration with the use of conventional techniques. Fabricating a crown for an implant that replaces the lost root involves challenges in terms of reproducing gingival contours as well as the exact color, shape, texture, and esthetic characterization. 6 The conventional approach for the clinical situation presented in this article would entail fabrication of a fixed partial denture or implant placement and the fabrication of a new crown. 5,6 However, reuse of the existing crown is suggested, since it conforms to an arch restoration with characterized metal ceramic crowns which are difficult to reproduce. The correct placement of the implant, based on a surgical guide, is essential to enable reuse of the existing crown. Removal of a fractured root atraumatically with a flapless approach and the immediate placement of an implant with the goal of preserving the buccal bone as well as the keratinized gingiva has been reported. 5 The advantages of this technique are a reduced number of surgical procedures, preserving blood supply to the bone and soft tissue, reduced postoperative swelling and discomfort, reduction of treatment time, and increased patient acceptance. 5-7 This article describes the reuse of a previous metal ceramic crown to restore an implant placed following extraction of the fractured root of a central incisor. CLINICL REPORT 61-year-old woman presented to a private dental practice with an existing maxillary rehabilitation consisting of metal ceramic crowns and a fixed partial denture from left canine to left second premolar. The patient reported tenderness to percussion of the maxillary left central incisor. Upon examination of the patient record and radiographs, it was noted that all of the maxillary crowns had been placed by the same dentist 10 years earlier. fistula and suppuration were observed in the labial gingiva of the maxillary left central incisor (Fig. 1). The crown did not demonstrate mobility. Radiographically, the presence of a long, thick, cast metal post was identified in the tooth, and minimal remaining tooth structure was observed, which is known to increase the risk of a root fracture (Fig. 2). 8 nalyzing the clinical and radiographic data, the diagnosis of a longitudinal root fracture of the maxillary left central incisor was made, which a ssistant Professor of Prosthodontics and Researcher, Federal University of Santa Catarina (UFSC). b Researcher, Department of Dentistry, Federal University of Santa Catarina (UFSC). c Titular Professor, Federal University of Santa Catarina (UFSC). d ssociate Professor, Division of Primary Oral Health Care; Don and Sybil Harrington Foundation Chair of Esthetic Dentistry, University of Southern California, School of Dentistry.
May 2010 263 1 Pretreatment clinical view. Note presence of suppuration at cervical facial aspect of maxillary left central incisor. 2 Pretreatment radiograph. 3, Occlusal view of fractured root., Placement of implant immediately after extraction. Note position of implant 1 mm apical to proximal bone crest and maintenance of gingival architecture was confirmed after the removal of the crown (Fig. 3, ). fter discussing the treatment options with the patient, including fabrication of a fixed partial denture or a new implant-supported crown, it was suggested that a dental implant be placed at the time of tooth extraction and loaded immediately with a provisional restoration. This procedure was accepted by the patient and performed after remission of the signs and symptoms of acute inflammation. 9 threaded titanium implant with an airborne-particle-abraded, acidetched surface and internal hex (Titamax II Plus, 3.75 x 15 mm; Neodent, Curitiba, razil) (Fig. 3, ) was placed following extraction, oriented by a surgical guide and by the dental alveolus anchored in the palatal wall. In view of the low insertion torque (20 Ncm) and the lack of sufficient implant primary stability, loading was delayed. During the 6-month healing period, an acrylic resin (Dencôr Lay; Clássico Ltda, São Paulo, razil) RPD was fabricated to replace the missing tooth. Six months after implant placement, a screw-retained provisional restoration was placed. Ideal gingival contours were developed by additive and subtractive modifications of the acrylic resin provisional crown until the ideal tissue architecture was achieved. The exact outline of the periimplant tissue contours was recorded in an impression and transferred to a stone (Durone IV; Dentsply Ind e Com Ltda, Petrópolis, razil) cast to guide the fabrication of the definitive prosthesis. For this purpose, a custom impression coping was fabricated by making an isolated impression of the cervical contour of the provisional implant-supported crown. The proper emergence contour was then developed for the impression coping (Transfer II Plus; Neodent) with acrylic resin (Duralay; Reliance Dental Mfg Co, Worth, Ill) 10 (Fig. 4). complete maxillary arch impression was made with silicone impression material (Express Impression Ma-
264 Volume 103 Issue 5 4 Placement of custom impression coping on implant. 5, Retrofitting custom abutment to existing crown., Completed custom abutment and crown. terial; 3M ESPE, St. Paul, Minn) using the closed tray technique. The custom impression coping was replaced in the impression. n elastomeric material for gingival reproduction (Gingifast; Zhermack Sp, adia Polesine, Italy) was injected around the custom impression coping. Finally, the impression was cast with fast-setting type IV gypsum (Durone IV; Dentsply Ind e Com Ltda). The cast was sent to the dental laboratory, where a cast-to abutment consisting of a plastic sleeve with a Ni-Cr-Ti alloy prosthetic-abutment interface (UCL II Plus; Neodent) was adapted to the preexisting crown. This abutment was fastened to the implant analog on the cast and adjusted until the crown seated completely and was judged to be accurately positioned, based upon comparison with a silicone putty index (Express Impression Material; 3M ESPE) that had been made prior to extraction. To retrofit the tooth-supported crown, first the abutment screw (UCL II Plus; Neodent) was protected with wax (Epoxiglass; Epoxiglass Chemical Products, São Paulo, razil) and petroleum jelly was applied to the intaglio surface of the crown. crylic resin (Pattern Resin; GC Europe NC, Leuven, elgium) was applied to the space between the cast-to abutment, the gingival tissue, and the intaglio surface of the crown (Fig. 5, ). The preexisting crown was then correctly positioned on the cast by means of the silicone index. fter polymerization of the acrylic resin, the crown was separated from the abutment and the excess acrylic resin was trimmed and polished with aluminum trioxide papers of 100 and 400 grit (3M do rasil, Ribeirão Preto, razil). The emergence profile, tissue support, and position of the custom abutment pattern and crown were evaluated intraorally. Once the correct contour and orientation were verified, the custom abutment pattern (Fig. 5, ) was invested, burned out, and cast using a Ni-Cr alloy (Veraond II; alba Dent, Inc, Cordelia, Calif) according to the manufacturer s recommendations. The cast custom abutment (Fig. 6, ) and corresponding crown (Fig. 6, ) were evaluated intraorally to ensure appropriate fit. torque of 20 Ncm was applied to the abutment screw, followed by fine occlusal adjustment of the crown. The crown was provisionally cemented for 1 week (RelyX Temp NE; 3M ESPE) and then definitively cemented with zinc phosphate cement (HY-ond Zinc Phosphate Cement; Shofu, Inc, Kyoto, Japan). Despite the loss of the papilla between the central incisors (Fig. 7), the patient was satisfied with her smile, which remained substantially unaltered (Fig. 8). The patient had been previously informed of the possibility of papilla loss, which has been described in lit-
May 2010 265 6, Intraoral view of custom abutment. Note optimal support for gingival tissue, without compression., Preexisting metal ceramic crown cemented on custom abutment. 7 Radiograph made 14 months after custom abutment placement. 8, Posttreatment facial view., Posttreatment smile. erature. 4,5 Ideally, a lateral extension of the proximal contours of both crowns (mini-wings) could compensate for the reduced papilla form and eliminate the black space. 11 Since there was an effort to preserve the adjacent crowns, mini-wings were not added. Following the treatment, gingival recession and exposure of metal margins on the adjacent teeth were observed, despite the flapless surgical approach. minor discrepancy in the position of the left central incisor compared to the preoperative condition was observed, as the mesial incisal edge appeared shorter. This can be attributed to lack of precision during the retrofitting of the crown to the definitive cast. The implant-supported crown has been in service for more than 14 months (and the remainder of the patient s complete maxillary rehabilitation for more than 11 years) without complications. The patient reported satisfaction and was thankful that the preexisting restorations could be preserved.
266 Volume 103 Issue 5 SUMMRY This article presents an alternative treatment for the restoration of a maxillary central incisor following root fracture, which preserves the integrity of an existing complete maxillary rehabilitation. Instead of fabricating a fixed partial denture or a new implant-supported crown, the preexisting metal ceramic crown was reused following extraction of the fractured root and immediate implant placement. This approach permitted preservation of the patient s esthetics, saved time, decreased costs, and minimized the psychological impact of anterior tooth loss. REFERENCES 1. Ozcan M, Niedermeier W. Clinical study on the reasons for and location of failures of metal-ceramic restorations and survival of repairs. Int J Prosthodont 2002;15:299-302. 2. Cardoso C, Spinelli Filho P. Clinical and laboratory techniques for repair of fractured porcelain in fixed prostheses: a case report. Quintessence Int 1994;25:835-8. 3. redfeldt G, Fattore L, Dixon R, Granado J. Use of an implant in repair of a fixed partial denture. clinical report. J Prosthet Dent 1991;65:3-6. 4. Galiatsatos. n indirect repair technique for fractured metal-ceramic restorations: a clinical report. J Prosthet Dent 2005;93:321-3. 5. Evans CD, Chen ST. Esthetic outcomes of immediate implants. Clin Oral Implants Res 2008;19:73-80. 6. Hess D, user D, Dietschi D, Grossen G, Schönenberger, elser UC. Esthetic single-tooth replacement with implants: a team approach. Quintessence Int 1998;29:77-86. 7. Swart LC, van Niekerk DJ. Simplifying the implant treatment for an unrestorable premolar with a one-piece implant: a clinical report. J Prosthet Dent 2008;100:81-5. 8. Morgano SM. Restoration of pulpless teeth: application of traditional principles in present and future contexts. J Prosthet Dent 1996;75:375-80. 9. Villa R, Rangert. Immediate and early function of implants placed in extraction sockets of maxillary infected teeth: a pilot study. J Prosthet Dent 2007;97(6 Suppl):S96-S108. 10.Elian N, Tabourian G, Jalbout ZN, Classi, Cho SC, Froum S, Tarnow DP. ccurate transfer of peri-implant soft tissue emergence profile from the provisional crown to the final prosthesis using an emergence profile cast. J Esthet Restor Dent 2007;19:306-14. 11.Magne P, Magne M, elser U. The esthetic width in fixed prosthodontics. J Prosthodont 1999;8:106-18. Corresponding author: Dr Luís Leonildo off Rua Joe Collaço, n.53 Florianópolis, SC RZIL 88037-010 Fax: +55 48 32345047 E-mail: luisboff@uol.com.br cknowledgments The authors thank Dr Robert Simon (Clinical Instructor, Division of Restorative Sciences, School of Dentistry, University of Southern California) for his help in revising and editing the English draft. Copyright 2010 by the Editorial Council for. ccess to Online is reserved for print subscribers! Full-text access to Online is available for all print subscribers. To activate your individual online subscription, please visit Online. Point your browser to http://www.journals. elsevierhealth.com/periodicals/ympr/home, follow the prompts to activate online access here, and follow the instructions. To activate your account, you will need your subscriber account number, which you can find on your mailing label (note: the number of digits in your subscriber account number varies from 6 to 10). See the example below in which the subscriber account number has been circled. Sample mailing label This is your subscription account number *********UTO**SCH 3-DIGIT 001 1 V97-3 J010 12345678-9 J. H. DOE 531 MIN ST CENTER CITY, NY 10001-001 Personal subscriptions to Online are for individual use only and may not be transferred. Use of Online is subject to agreement to the terms and conditions as indicated online.