Perio Contest 2018/ 6 April 2018/

Case 7 | Perio Contest 2018 | Canada

Dr Les Kalman

A Congenitally Missing Lateral and a Transposed Canine: A Before and After Case Study

Implant placement in the anterior maxilla can be an ideal treatment option for patients, provided that the clinician properly plans the treatment. Several treatment factors should be considered: those that relate to patient, the biology of the site and the experience and skill of the clinician. These factors must be evaluated to result in a predictable esthetic outcome.

Introduction

Provided that proper treatment planning has been completed, implant placement in the esthetic zone is an ideal treatment option. Several crucial patient factors exist for success, including: patient expectations, smile line, gingival biotype, absence of infection and the width and height of the hard and soft tissues1.

Once proper candidate selection and treatment planning have occurred, it is crucial that the clinician follows established surgical protocols. Surgical considerations include proper implant size selection, implant placement and management of the soft tissues2.

Clinic Case

Presentation

A 22 year old male patient presented with a missing canine (Figure 1). Medical history was non-contributory. Clinical and radiographic examination indicated a missing lateral incisor (figures 2,3). The canine had migrated into the lateral’s space (Figure 4, 5). Diagnoses included the following: congenitally missing tooth #22, transposition of tooth #23 (into the space required for #22). Treatment options to replace the missing tooth included: an implant supported crown to occupy the canine space, a fixed bridge from the transposed canine to the premolar, a removable cast or transitional partial denture and no treatment. The patient had made it clear that he did not want to explore any orthodontic options. Therefore, distalizing the canine was not possible. Based on the options, the patient agreed upon the implant option. However, the esthetic problem of the transposed canine remained. It was proposed to initiate elective endodontic treatment and then shape the canine into that of a lateral and use composite resin to complete the transformation. Endodontic therapy was required, as crown shaping would have caused pulpal involvement. Treatment options for the canine included full or partial indirect coverage. The patient requested to try aless expensive alternative and the use of composite was agreed upon. Informed consent was given for the patient to review prior to the treatment.

Surgery

Prior to surgery, informed consent was obtained, vitals were taken and the patient rinsed with a 0.12% chlorhexidine rinse for 30 seconds. Local anesthetic was administered. A rubber dam and clamp were utilized. Tooth #23 underwent standard endodontic therapy and was obturated with Thermafil (Dentsply). The tooth was shaped into an approximation of a lateral, and the remaining restoration was completed using composite resin.

A flapless approach was used for implant placement to minimize trauma3. A surgical stent was used for the pilot drill followed by an osteotomy to a diameter of 3.5mm and a depth of 11mm. The site was tapped. A 4.1mm diameter, 10mm long standard Straumann regular neck implant was placed according to standard surgical protocols. A healing cap was placed and a radiograph taken to confirm position. The edentulous area was temporized with an acrylic pontic that was bonded to the adjacent teeth. The pontic addressed the esthetic concern, as well as maintained the soft tissue architecture. The patient was dismissed with a course of analgesics, antibiotics, a 0.12% chlorhexidine rinse and post-operative instructions. One week post-operative examination was unremarkable.

Prosthodontics

The patient returned 10 weeks following surgery. A periapical radiograph and clinical examination indicated that healing was within normal limits. The healing cap was removed. An impression coping was threaded into the implant and was verified by a radiograph. An open modified tray poly-vinyl siloxane (PVS) impression was taken using the Reseat Technique4. An alginate mandibular impression was taken, as well as a PVS bite registration. Shade selection followed. The healing cap was replaced and the patient dismissed.

When the laboratory case was completed, the milled titanium custom abutment and porcelain fused to metal (PFM) crown were assessed on the master cast. The patient returned after a 2 week interval. The healing cap was removed. The custom abutment was threaded into the implant. A radiograph confirmed seating. The abutment was torqued to specifications (30 Ncm). A cotton pellet was placed into the crew head, followed by a drop of PVS material to act as a seal. The PFM crown was placed onto the abutment and was assessed according to fit, marginal integrity, esthetics and occlusion. The patient confirmed the esthetics (Figure 6,7,8). The crown was cemented with a permanent glass ionomer cement (Fujicem (GC)). Excess cement was cleaned, occlusion refined and the crown polished. A post-cementation radiograph was taken (Figure 9). The patient was given post-cementation instructions and dismissed. The patient returned 48 hours later for a follow-up appointment to confirm the occlusion.

Discussion

Several factors presented that made this situation unique. The patient was not interested in any orthodontic treatment and he understood that an alternative treatment plan would be compromised. The patient also requested a least-cost option for the esthetic restoration of the transposed canine. It was made clear that future full coverage would be required. The biology of the site was ideal, as there was adequate bone width and depth. Soft tissue was also in abundance, thereby eliminating the immediate need for any soft tissue grafting. During the osteotomy, it was apparent that the patient had dense bone (D2), allowing for the tapping of the bone and a very stable implant following surgery5. The patient’s occlusion was favourable, allowing for the proper distribution of occlusal forces. Lastly, the patient was motivated and proactive during the healing and maintenance phase.

Conclusions

Implant placement in the anterior maxilla is a viable and predictable treatment option. There exists several crucial factors for a successful outcome, including proper surgical and prosthodontic protocols, biological considerations and patient selection.

References

Martin, W.C., Morton, D. and Buser, D. Pre-operative analysis and prosthetic treatment planning in esthetic implant dentistry. In Buser, D., Belser, U. and Wismeijer, D. editors: Implant Therapy In The Esthetic Zone-Single Tooth Replacements (Volume 1) p11-19, Berlin, 2007, Quintessence.

Buser, D., Martin, W.C. and Belser, U.C. Surgical considerations for single-tooth replacements in the esthetic zone: standard procedure in sites without bone deficiencies. In Buser, D., Belser, U. and Wismeijer, D. editors: Implant Therapy In The Esthetic Zone-Single Tooth Replacements (Volume 1) p26-31, Berlin, 2007, Quintessence.

Sammartino, G., Marenzi, G., Espedito di Lauro, A. and Paolantoni, G. Aesthetics in oral implantology: biological, clinical, surgical and prosthetic aspects. Implant Dentistry. 2007;16:54-58.

Kalman, L. The Reseat Impression Technique: An Open Tray Alternative. In Press

Misch, C.E. Bone Density: A key determinant for clinical success. In Misch, CE, editor: Contemporary Implant Dentistry (2nd Ed.) p113-114, St. Louis, 1999, Mosby.

Figures

Pre-Operative-Retracted.