[Morphology of implant restorations in the cuspid area]

Implant supported posterior restorations must be constructed following established prosthetic principles. The need for screw-retained abutments and the narrow diameter of root form implants dictate additional treatment protocols that fail beyond the scope of conventional prosthetics. Cemented restorations offer simplicity and good control of morphology, but can only be considered if no reservicing and removal of the restoration are anticipated. Screw retained restorations allow for reservicing on remediation but necessitate centering of the fastening screw within the occlusal anatomy. In case of implant misalignment, axis problems are solved with preangled or customized copings, or double frameworks. The diameter of root form implants is significantly smaller than posterior natural teeth and the emergence of the restorations must be progressively flared to achieve proper anatomy. Limited interocclusal space and implant placement may dictate restoring posterior teeth as premolars selecting a short abutment or a UCLA abutment, or overlapping the crowns over the soft tissues. The final selection is best assisted with a diagnostic waxing and with provisional restorations anticipating the completed treatment.