In deciding between a fixed partial denture and an implant for a posterior mandible with adequate bone, which criterion weighs most heavily?

• A. Color of teeth
• B. Brand of implant
• C. Functional occlusion
• D. Patient's age

Answer: (C)

In restoring a posterior mandible with adequate bone, how the bite functions and how forces are transmitted through the prosthesis are the most influential factors. The restoration must integrate into a stable occlusal scheme that distributes chewing forces evenly and avoids harmful nonaxial loading. If occlusion isn’t optimized—centric contacts, proper disclusion in excursions, and appropriate occlusal clearance—the chosen restoration (whether a fixed partial denture or an implant-supported prosthesis) is prone to overload, leading to issues like implant bone loss, screw loosening, or fracture of teeth or prosthetic components. That is why functional occlusion weighs most heavily.

Aesthetics (color of teeth) and the brand of implant are important but do not determine the biomechanical success as directly, and patient age is a general consideration rather than the decisive factor for load management. The crucial question is how the restoration will function under chewing loads and how well the occlusal scheme can be harmonized with the patient's bite.