A major cause for dental resin composite restoration replacement is secondary caries attributed to Streptococcus mutans. Salivary esterases were shown to degrade resin composites. Hypothesis: S. mutans contain esterase activities that degrade dental resin composites and adhesives. Esterase activities of S. mutans were measured using synthetic substrates. Standardized specimens of resin composite (Z250), total-etch (Scotchbond-Multipurpose, SB), and self-etch (Easybond, EB) adhesives were incubated with S. mutans UA159 for up to 30 days. Quantification of a bisphenol-glycidyl-dimethacrylate (BisGMA)-derived biodegradation by-product, bishydroxy-propoxy-phenyl-propane (BisHPPP) was performed using high performance liquid chromatography. Results: S. mutans were shown to contain esterase activities in levels comparable to human saliva. A trend of increasing BisHPPP release throughout the incubation period was observed for all materials and was elevated in the presence of bacteria vs. control for EB and Z250 (p<0.05) but not SB. Conclusion: biodegradation by cariogenic bacteria could compromise the resin-dentin interface and reduce the longevity of the restoration.
| Identifer | oai:union.ndltd.org:TORONTO/oai:tspace.library.utoronto.ca:1807/42692 |
| Date | 21 November 2013 |
| Creators | Bourbia, Maher |
| Contributors | Finer, Yoav |
| Source Sets | University of Toronto |
| Language | en_ca |
| Detected Language | English |
| Type | Thesis |
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