#4/#5 RCT, Crown Lengthening, Zirconia Crowns

Patient presented with pulpal pathology associated with tooth #4. During access and canal exploration, the tooth was found to have a 1–2–1 canal morphology, where a single canal bifurcates into two canals within the root and then rejoins apically. Both canals were identified, negotiated, and instrumented. The canals were cleaned, shaped, and obturated without complication.

At the same appointment, root canal therapy was also completed on tooth #5. Core build-ups were placed on both teeth #4 and #5 following obturation to restore structural integrity and prepare the teeth for definitive full-coverage restorations.

Root canal therapy and core build-ups on both teeth were completed in approximately 2.5 hours.

Patient returned for definitive restoration following completion of root canal therapy and core build-ups on teeth #4 and #5. Both teeth were prepared for full-coverage zirconia crowns. During preparation of tooth #4, the buccal margin was noted to extend approximately 5 mm subgingivally. Radiographic evaluation and clinical analysis were performed, leading to a diagnosis of altered passive eruption contributing to inadequate clinical crown height.

The zirconia crown for tooth #5 was delivered and definitively cemented. Due to the subgingival margin and need for improved ferrule and biologic width management, a provisional crown was placed on tooth #4 and the patient was scheduled for crown lengthening.

Following preparation of tooth #4, the buccal margin was noted to extend significantly subgingivally. In order to ensure accurate seating of the interim restoration and proper marginal adaptation, a small gingival flap was reflected on tooth #4 to expose the preparation margin. This allowed for clear visualization of the margin and ensured that the provisional crown could be fully seated without impingement on the surrounding tissue.

The patient resided out of state and was unable to return to the clinic for approximately two months. Because of this extended interval between visits, particular care was taken to ensure that the provisional restoration had precise marginal adaptation and proper contour to protect the preparation and maintain periodontal health during the interim period.

The patient subsequently returned for crown lengthening on tooth #4 to establish appropriate clinical crown height and margin accessibility. Following healing and refinement of the preparation, the definitive zirconia crown for tooth #4 was fabricated, delivered, and cemented. Occlusion, margins, and contacts were verified at delivery.