Use of a modified reversible hydrocolloid syringe for stick modeling compound

Abstract

The technique should (1) be easily performed in the laboratory on a routine basis, (2) significantly enhance the rigidity of the removable partial denture framework, and (3) increase the strength of the attachment of the acrylic resin portion containing the denture teeth and the denture base retention to the cast framework. These goals are achieved by use of an added metal cingulum that increases the rigidity of the cast framework and by use of labial loops that provide additional rigidity to the lingual bar and strong mechanical anchorage for the acrylic resin part of the removable partial denture. 1. During the design procedure, decide whether to use open lattice retention or bead retention and note this on the diagnostic cast and work authorization form. Either form of acrylic resin retention may be used. In the absence of factors such as recent extractions or ongoing periodontal disease of abutment teeth, beaded retention is recommended. 2. Make a vertical cingulum continuous with the approximate height and location of the cingulums of the anterior incisors being replaced. The cingulum can be either smooth or scalloped along its superior border and should follow the anterior-posterior curvature of the ridge (Fig. 4). A useful guideline that allows for ridge resorption is to make the wall of the vertical cingulum approximately three fourths as high as the length of the replacement denture teeth. The horizontal denture base retention portion of the framework may be relieved or fit directly against the cast (Fig. 5). 3. When waxing the framework, place retention loops on the labial surface of the vertical cingulum (Fig. 6). The loops are made from small l&gauge round wax forms. Angle the loops in a cervical and labial direction (Fig. 7). Keep the loops small so they will not interfere with the arrangement of the denture teeth. When the denture teeth are set and processed, the loops provide secure retention and the vertical cingulum wall and loops add a great amount of rigidity to the framework (Fig. 8).