Temperature & Humidit6y Insensitive Dental Restorative and Impression Mataerials

This proposal seeks to determine the feasibility of developing new, polymeric dental restorative and impression materials that will not only withstand high temperature and humidity conditions but also retaining their physical and mechanical properties. The procedure will involve the selection or the synthesis of heat and moisture resistant resins and curing agents; the development of optimum silane content on the filler surfaces via FTIR; the formulation of restorative/impression materials utilizing above components and the characterization of the formulated products. For restoratives, modified Bis-GMA analogues and/or diluents having optimurn viscosity, hydrophobicity and reactivity will be used to mix with properly silanated siliceous fillers, stable initiators, accelerators and stabilizers. For polyether impression, bulky carbocationic initiators will be tried in lieu of conventionally used aryl sulphonate esters. For polyvinylsiloxane impression. use of either hydrido-silanes having bulkier derivatives as cross-linkers or inorganic/organometallic catalysts or combinations will be explored. Changes in viscosity, curing parameters and mechanical properties such as hardness, tear and flexural-strength will be monitored under different temperature and humidity conditions to make shelf-life predictions. Development of one part vinyl impression material will be investigated to further enhance the shelf stability. The immediate benefits will be shared by the government and the taxpayers. Long-term benefits are the development of storage stable, new products, that will find wide acceptance in the dental community worldwide.