Polydimethyl siloxane materials in maxillofacial prosthetics: evaluation and comparison of physical properties.

The need for more acceptable materials for use in maxillofacial prosthetics has long been recognized. In this study, the physical properties of several currently available polydimethyl siloxane materials were evaluated and compared with those of two previously tested materials. The properties chosen were tensile strength, elongation, tear strength, and hardness. These properties were chosen as indicators of the strength, flexibility, durability, and lifelike feel of the materials in clinical service. Testing procedures were intended to duplicate as nearly as possible those used by Chalian and Jones and to conform closely to ASTM specifications. In general, the physical properties of the five silicone materials tested in this study were superior to those of MDX-4-4210 and MDX-4-4514, tested previously. This superiority was particularly evident in terms of strength and elongation. Although the materials failed to demonstrate the softness of other materials, they may prove acceptable with the addition of available modifiers. Although no material was consistently superior to the others, potential merit is seen especially in Q7-4635 and SE-4524U. These materials exhibited high strength and softness and are available in one component system. Unlike the two-component addition chemistry systems, these materials have an indefinite pot life and are much more easily manipulated.(ABSTRACT TRUNCATED AT 250 WORDS)