The future of complete prosthodontics.

An improved elastomer with an optimum balance of mechanical properties, processability, environmental stability, colorability, and esthetics, for use in fabricating extraoral maxillofacial prostheses, was sought, An arylene silicone polymer, polytetramethylsilphenylenesiloxanedimethylsiloxane, was synthesized and formulated as a pourable, viscous, room-temperature-vulcanizing liquid. Silphenylene polymers are colorless and will accept either intrinsic or extrinsic coloration. When mixed with conventional catalysts, the silphenylene vulcanizates can be easily and reliably cast in closed dental stone molds to give prostheses that are strong and tough yet soft and pliable. Typical values for tensile strength, elongation at break, modulus at 100% elongation, and hardness are, respectively, 1400 psi, 1000 psi, 50 psi, and 35 (Shore A). Since the arylene linkages in the silphenylene polymers impart unusually high values of surface energy to these silicone elastomers, they have an excellent tactual as well as visual resemblance to skin, and they adhere well to tapes and adhesives. A preclinical toxicologic evaluation has been completed, and the materials are currently undergoing clinical evaluation.