SBIR-STTR Award

This research will develop improved composite dental restorative materials based on organosilicon polymers. By proper selection of organosilicon monomers and optimization of composite formulation, the monomers are expected to enhance the bonding between the filler and the polymer matrix and minimize the chemical degradation and water sorption. The major aim of the research is to develop composite materials based on organosilicon polymers that are highly durable and resistant to wear,and thus are suitable for use in posterior restorations as well as anterior restorations. Specifically, it is planned to use high-molecular-weight siloxane monomers to prepare visible light-activated microfilled composites. The composites will be evaluated in vitro. Hardening time, hardness, diametral tensile strength, and water sorption of the composites will be determined and compared with those of BIS-GMA-based composites. The degree of conversion of the siloxane monomers will be determined by infrared spectroscopy and correlated with their chemical structures and performance as the composite polymer matricesAwardee's statement ofthe potential commercial applications of the research:Potential commercial applications of the research include improved dental composite restorative materials that are highly durable and resistant to wear in the oral environment, and are suitable for use as a posterior restorative as well as an anterior restorativeNational Institute of Dental Research (NIDR)

This research aims to develop improved composite dental restorative materials. In phase I, high molecular weight siloxane monomers were used to prepare visible light-activated composites, and the composites were evaluated according to ADA specification No.27. Hardness, diametral tensile strength, and water sorption of the composites were determined as well as the degree of conversion of the siloxane monomers which were determined by ATR infrared spectroscopy. Among the siloxane monomers studies, a siloxane monomer showed a high degree of conversion, and a low water sorption. Further, the high molecular weight monomer does not require a diluent, and mechanical properties of the siloxane composites are comparable to those based on Bis-GMA. In phase II, the composite formulations will be further optimized by determining the optimum filler composition and concentration; by studying the polymerization shrinkage, microleakage, and contraction stress relaxation of the composites; by determining the wear of the composites in artificial oral environment; and by improving the color stability of the composites. The major aim is to develop improved composite materials which are suitable for posterior restorations