title: [The effect of matrix metalloproteinase-1 on root surface dentin matrix: a scanning electron microscope observation].
abstract: OBJECTIVE
  To observe the effect of matrix metalloproteinase-1 (MMP-1) from human host on degradation of dentin organic matrix of root dentin.
  
  
  METHODS
  The freshly extracted caries-free impacted teeth were selected. Teeth were cut transversely under the enamel-cementum junction into dentin sections with a thickness of about 5 mm. Then all sections with removal of cementum, pulp and predentin were randomly divided into four groups. In the first group, dentin sections were demineralized with acid solution for 21 days, and then incubated with MMP-1 solution for 7 days; the second group were only treated with acid solution for 21 days; the third group were only attacked by MMP-1 solution for 7 days; and the fourth group were untreated as a control. Then all sections were dehydrated in ascending strength of alcohol, critically dried, coated with platinum, and then observed under scanning electron microscope(SEM).
  
  
  RESULTS
  The dentin sections of root surface attacked by acid and MMP-1 showed that demineralization of dentin mineral and degradation of dentin matrix fibrae synchronously happened. The dentin matrix fibrae wasn't degradated in the groups treated with acid or MMP-1.
  
  
  CONCLUSIONS
  The proteinases from human host may play an important role in the development of root surface caries. MMP-1 may distinctly degradate the organic matrix of demineralized dentin.
authors.affiliation: Dept. of Endodontics, College of Stomatology, Shandong University, Jinan 250012, China.
authors.forename: Chang-Li
authors.initials: CL
authors.lastname: He
authors.forename: Duo
authors.initials: D
authors.lastname: Wang
authors.forename: Zhen-Hua
authors.initials: ZH
authors.lastname: Liu
authors.forename: Jie
authors.initials: J
authors.lastname: Jin
authors.forename: Yan-Hong
authors.initials: YH
authors.lastname: Gong
mesh_terms: D003739:Dental Cementum; D003743:Dental Enamel; D003804:Dentin / Q000201:enzymology*; D006801:Humans; D020781:Matrix Metalloproteinase 1 / Q000502:physiology*; D064347:Microscopy, Electrochemical, Scanning; D017213:Root Caries / Q000201:enzymology*; D014092:Tooth Root / Q000201:enzymology*
chemical_list: D020781:Matrix Metalloproteinase 1