ABSTRACT
Clinicians commonly contend that the screw-retained, implant-supported fixed dental prosthesis (FDP) should be fabricated with all nonengaging abutments to allow for the inherent nonparallelism of the implants and the inability of the abutment connections to draw together during insertion and removal. The problem with a fully nonengaging FDP is difficulty in handling and more strain on the abutment screws, ultimately leading to increased rates of breakage and loosening. The hemi-engaging FDP design regains much of the advantage afforded by the internal connection and improves prosthetic handing both clinically and in the laboratory. The benefits of this technique are best seen for short-span (fewer than 5 units), screw-retained, implant-supported FDPs.
