One of the most common reasons for the replacement of dental restorations is recurrent (secondary) caries at the gingival tooth-restoration interface. Human salivary enzymes such as esterases hydrolyze dental resins to produce biodegradation products. A two-fold approach is proposed wherein: 1] the elution of biodegradation products of composite and adhesive resins will be examined after long-term salivary esterase exposure, and 2] the impact of long-term salivary esterase exposure on the oral microbiome will be characterized. This proposal offers a novel in vitro approach that correlates changes in the microbial ecology of oral biofilms grown on dental adhesive and composite resins under clinically relevant conditions. The methodology proposed will be beneficial for the testing of future resin composite and adhesive resin formulations, and could easily be adapted to assess biodegradation in other types of biomaterials. The proposed project will strengthen the research environment of an educational institution that has not been a major recipient of NIH funds, which is a goal of the R15 (AREA) award.
The cost of replacing direct resin restorations is estimated to be in the billions of dollars and is increasing annually. The knowledge gained from the proposed research will provide fundamental information about the change in the ecology of biofilms grown on dental composite and adhesive resins after they are exposed to long-term salivary esterase-mediated biodegradation, as experienced by restorations after placement in the mouth.
