Enamel surface changes caused by hydrogen sulfide

BACKGROUND: Volatile sulfur compounds (VSCs) produced inside the mouth are a well-known cause of halitosis. Recent studies have suggested that VSCs modify the pathology of periodontitis by encouraging the migration of bacterial toxins associated with increased permeability of gingival epithelia, and enhancing the production of matrix metalloproteinases in gingival connective tissue. Nonetheless, the effects on the enamel of direct exposure to VSCs within the oral cavity remain unclear. In the present study, we observed the effects of VSCs in the form of hydrogen sulfide (H(2)S) on enamel surfaces and determined their effects on restorations. MATERIALS AND METHODS: Extracted human tooth and bovine tooth samples were divided into the H(2)S experimental side and the control side. We observed the effects of H(2)S on enamel surfaces using electron microscopy and conducted a shear test. RESULTS: We found that exposure to H(2)S obscured the enamel surface's crystal structure. The surface also exhibited coarseness and reticular changes. Shear testing did not reveal any differences in bond strength. CONCLUSIONS: Our findings suggested that H(2)S occurring inside the mouth causes changes to the crystal structure of the enamel surface that can lead to tooth wear, but that it does not diminish the effects of dental bonding in adhesive restorations.