This composite system consists of a novel, non-toxic, thiol-ene-based "smart" polymer as its continuous phase, which features low shrinkage stress, not air inhibited, low extractable content, and mechanophoric self- reporting of stress. This polymer will be filled in total with silanated silica particles or in part with fluorapatite crystals of nano to micro size that are similar in shape and composition to enamel crystals. These crystals will impart a bioactivity to the filler particles in the areas of;epithelial/pulp cell biocompatibility, remineralization capabilities, and antibacterial activity. The polymer system will be self-adhesive to eliminate the need for a separate bonding agent and to reduce technique sensitivity. Evaluation of the composite will follow ISO standards for minimal acceptance for resin composite materials along with testing techniques for proteolytic degradation, antibacterial activity against pathogenic oral bacteria, ion release and in vitro biocompatibility using appropriate cell lines, dental pulp stem cells, gingival fibroblasts and osteoblast-like cells. Bench marking of the mechanical properties will be based on ISO guidelines and published data on contemporary clinically used composites with shrinkage vol. of the polymer of less than 8% and the composite less than 4% vol. as stated in the RFA but with a goal of 1% vol. The overall objective of this U01 application is to produce a composite that will double the clinical life-time of the composites used in dental practice today.
This research involves the design and development of a white filling material which lasts twice as long as those now is being used by dentists. The filling material will be able to inhibit bacteria that cause dental decay and release compounds that will heal any decay that occurs around the restoration. It also has a special property that will tell the dentist, by changing color, whether the filling material has been placed into the cavity incorrectly. The filling material will be evaluated using standard mechanical and biological tests.