John R. Ivanhoe

A silicone obturator for the access canal in an implant-retained fixed prosthesis

The insertion of a Branemark implant-retained fixed prosthesis involves the obturation of the access canals to the gold screws. This ohturation has been accomplished with a variety of materials that include gutta-percha and IRM (Intermediate Restorative Material, L. D. Caulk Co., Milford, Del.) materia1.l The removal of these obturation materials is tedious and can result in damage to the gold screws and the access canals by their removal with rotary instruments and the lack of protection for the screws and access canal walls. A technique is described that isolates the screws, preserves the canal form, and allows for easy access and removal of the screws.

A technique to determine a desired preparation axial inclination

The guidelines recommended in the literature for the convergence angle of a crown preparation vary from 3 to 24 degrees. There is a lack of guidelines on techniques to achieve a specific axial inclination. The purpose of this article was to present a practical technique, with a diamond rotary cutting instrument of known axial inclination, to determine the diamond rotary cutting instrument angulations required to achieve the desired axial inclination of a preparation.

A simplified technique for fabricating esthetic cast metal occlusal surfaces for dentures

This article describes a simplified method for making esthetic cast metal occlusal surfaces. Monoplane posterior acrylic resin block teeth, cast in a nickel-chrome alloy, are coated with silane and an esthetic composite resin veneer is applied to the buccal surface. These veneered posterior metal teeth are incorporated in the wax setup and the dentures are processed and finished. The dentists routine technique for delivering dentures to the patient can be followed.

Cone positioning device for oral radiation therapy

This article describes the fabrication and modification of a peroral cone-positioning device. The modification provides added cone stability and prevents tongue intrusion into the radiation field. This device provides a repeatable accurate cone/lesion relationship and the fabrication technique is simplified, accurate, and minimizes patient discomfort.

A cast orientation index.

This article describes a technique that allows multiple master casts to be precisely oriented to the same path of insertion and withdrawal. This technique is useful in situations where multiple fixed prosthodontic preparations require surveyed restorations and a single master cast is not available.