Controlled retainer-screw access placement for screw-retained implant prosthesis

An implant-supported prosthesis is often secured to the underlying gold cylinders by retaining screws. There must be access to these screws from the oral surface of the prosthesis. Conventional preparation of this access is from the oral surface. This approach is difficult because the underlying gold cylinder is obscured. It may be damaged by a rotary cutting instrument as the access is prepared above it, because the cylinder cannot be seen during the preparation. Alternatively, the access hole may be unnecessarily enlarged in an attempt to find the cylinder. This loss of structure may weaken the prosthesis. A new approach, using 18-gauge stainless steel wire as a rotary cutting instrument, permits preparation of the access chamber from the intaglio surface of the prosthesis. This reduces risk of damage to the gold cylinder and is less destructive to the overlying material.