Following upon seven years of support by the NIDR (1980-87), a polyphosphazene polymer was introduced to dentistry as a permanent resilient denture liner (Novus by Hygenic) in 1989. This marked the first use of this novel material for biomedical purposes. It is unique from its chemistry (phosphorus-nitrogen backbone), biocompatibility, low Tg, and good solvent resistance; properties of phosphazene can be designed with proper choice of pendant groups. Working with Prof. Allcock who did the original work on these polymers, new phosphazenes will be synthesized for dental purposes, and then compounded with additives and tested for chemical and physical properties. Potential end uses include four substances for restorative dentistry or in applied sciences: a) Chairside resilient denture liner are needed for the 30 million US denture wearers on a periodic basis. Conventional materials lack longevity for more than a few months for various causes. New phosphazenes purchased from Penn State with possible lower MW, improved crosslinking by choice of active sites, alternative fluorocarbon side groups, and visible light curing. b) the above mentioned polymers will be evaluated for use as extraoral maxillofacial prostheses, usually for cancer patients. Further modifications will be done if indicated. c) Hard phosphazene polymers will also be purchased for use as a hard composite resin. They will be blended with fillers and couplers and tested for physical and chemical properties. d) A current-conducting phosphazene will be used, with noble and base metals, in studies on the adhesion of Pseudomonas aeruginosa to their surfaces. New, sensitive electrochemical methods will be applied in addition to traditional microbiologic techniques. This AREA grant proposal will establish a collaboration between UofL's schools of dentistry and engineering, making use of student workers at both.
