Optimizing Implant Esthetics With Resin Cements

Fig 1. During the healing phase a layered zirconia Maryland bridge was used due to hard- and soft-tissue augmentation that was performed simultaneously with the extraction and implant-fixture placement. The etched enamel was primed with All-Bond Universal® adhesive (Bisco). The bridge was treated with Z-Prime Plus and luted with flowable composite.

Fig 2. The zirconia Maryland bridge was dislodged by gently prying at slots placed on the periphery of the wings. Residual composite was removed by gently using a 12-fluted carbide finishing bur with no irrigation to better identify the cement.

Fig 3. Note the palatal position of the implant fixture. The cover screw was accessed by perforating the gingiva using a coarse diamond bur. The opening was minimally enlarged to remove the cover screw, remaining palatal to the platform. A healing abutment was used to push the soft tissues facially.

Fig 4. The screw-retained provisional was tried in, and modifications were made to optimize the soft-tissue contour. A convex surface was created along the entire profile of the provisional, at and below the level of the gingiva, to maximize the volume of soft tissue.

Fig 5. Gentle pressure was exerted on the facial gingiva to adequately support it until the final prosthesis was fabricated. Too much pressure may cause recession of the facial gingiva, and too little pressure may cause blunting of the papilla.

Fig 6. The CAD/CAM hybrid zirconia abutment was joined to the titanium base using Z-Prime Plus and TheraCem. Enough TheraCem was used to ensure complete contact between the titanium base and the zirconia abutment. The opacity of the TheraCem prevented darkness from showing through the zirconia.

Fig 7. After a month, the hybrid zirconia custom abutment was tried in. The gingival architecture was reestablished with the provisional, and the prosthetic margins of the hybrid abutment supported the papillae. The abutment and porcelain-layered zirconia crown were treated with Z-Prime Plus.

Fig 8. The hybrid abutment reestablished the facial gingival profile, which was lost during the repair of the buccal plate. The esthetic margins were approximately 0.75-mm subgingival on the mesial and facial, and 0.5-mm subgingival on the distal, minimizing cement retention. The lingual margin was at or above the gingiva, allowing visual confirmation of complete seating of the crown.

Fig 9. Before final cementation, the prosthetic screw was torqued, which was repeated after 1 minute. Polytetrafluoroethylene tape was condensed into the screw channel, leaving at least 3 mm from the top of the screw channel. This space would serve as an air gap to minimize cement from flowing subgingivally.

Fig 10. To achieve maximum bond strengths, the abutment and crown were treated with Z-Clean™ (Bisco), rinsed, and dried. Duo-Link Universal was used to maximize translucency between the crown and the abutment. Limiting cement placement to the deepest third of the crown intaglio minimized excess subgingival cement.10

Fig 11. The final crown was in harmony with the facial gingival profiles and incisal edges of the adjacent teeth, as well as the maxillary and mandibular lip lines.

Fig 12. The final radiograph verified that all interproximal cement had been removed and served as a baseline to measure the rate of future bone loss. The radiograph also demonstrated excellent adaptation of the custom hybrid abutment to the implant platform and of the crown to the abutment.