title: Enamel surface changes caused by hydrogen sulfide.
abstract: 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 (H2S) on enamel surfaces and determined their effects on restorations.
  
  
  METHODS
  Extracted human tooth and bovine tooth samples were divided into the H2S experimental side and the control side. We observed the effects of H2S on enamel surfaces using electron microscopy and conducted a shear test.
  
  
  RESULTS
  We found that exposure to H2S 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 H2S 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.
authors.affiliation: Department of Endodontology, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama 230-8501, Japan.
authors.forename: Takao
authors.initials: T
authors.lastname: Yamaguchi
authors.affiliation: Department of Operative Dentistry, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama 230-8501, Japan.
authors.forename: Masao
authors.initials: M
authors.lastname: Hanabusa
authors.affiliation: Department of Endodontology, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama 230-8501, Japan.
authors.forename: Noriyasu
authors.initials: N
authors.lastname: Hosoya
authors.affiliation: Department of Oral Anatomy, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama 230-8501, Japan.
authors.forename: Toshie
authors.initials: T
authors.lastname: Chiba
authors.affiliation: Department of Endodontology, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama 230-8501, Japan.
authors.forename: Takumasa
authors.initials: T
authors.lastname: Yoshida
authors.affiliation: Department of Endodontology, Tsurumi University School of Dental Medicine, 2-1-3 Tsurumi, Tsurumi-ku, Yokohama 230-8501, Japan.
authors.forename: Akiyuki
authors.initials: A
authors.lastname: Morito
keywords: Hydrogen sulfide; tooth enamel; tooth wear; volatile sulfur compounds