#6 The Influence of Keeper Tray Materials on Casting Precision
Kogiso T., Sakane M., Nakamura Y., Kumano H., Ohno Y., Tanaka T1., Okada M1., Tanaka Y.
Removable Prosthodontics, School of Dentistry, Aichi-Gakuin University 1 Department of Dental Laboratory , Aichi - Gakuin University Dental Hospital
There are two techniques to fabricate a denture keeper coping with magnetic attachments: direct-bonding and cast-bonding techniques. A plastic pattern is used in the direct-bonding technique. In the cast-bonding technique, a wax pattern of the coping along with the keeper was invested and cast. Problems including a rough surface and a misrun in the corner are indicated for a keeper coping fabricated by the direct-bonding technique using a ready-made tray. We developed a keeper tray prototype made of polyethylene to overcome these problems, and compared the casting precision with a conventional tray. 　   The chief component of a keeper tray prototype was polyethylene, whereas a conventional tray was made of acrylic. The following two samples were prepared using these materials: 1. Keeper tray, and 2. Keeper coping by adding clinically-used dental wax.