title: [Influence of surface roughness of pure titanium on accumulation of bacterium].
abstract: OBJECTIVE
  The aim of this investigation was to evaluate the influence of surface roughness of pure titanium on adhesion of bacterium.
  
  
  METHODS
  A total of six edentulous volunteers with healthy oral mucosa participated in an in vivo study. Four kinds of pure Titanium testing pieces with different surfaces were fixed in the polished surface of upper complete dentures and the other in the tissue surface of the dentures. After 6-month wearing the dentures, the amount and species of bacterium adhered on pure Titanium were examined.
  
  
  RESULTS
  (1) Individual difference had a significant influence on amount of bacterium adhered on pure Titanium, but had no relation to species of bacterium according to Gram's staining. (2) To the same patient, with the increase of roughness, bacterium adhered on samples improved in amount (P < 0.01), but remained the same in composition. Wrinkly samples collected more bacterium than plane samples and exhibited G- coccus beside G+ coccus. Comparing two samples with same roughness, the one with roughness on the tissue surface of the denture collected less bacterium than that on the polished surface (P < 0.01), and predominantly presented G- rod bacterium and coccus, which was completely different to that on the polished surface.
  
  
  CONCLUSIONS
  From the perspective of benefit to periodontal tissue, plane surface should be adopted when framework of pure Titanium is made, and polishing of the prosthesis after being modified should be paid more attention, especially on the tissue surface.
authors.affiliation: Department of Stomotology of Changhai Hospital, The Second Military Medical University, Shanghai 200433, China.
authors.forename: X
authors.initials: X
authors.lastname: Li
authors.forename: T
authors.initials: T
authors.lastname: Guo
authors.forename: Z
authors.initials: Z
authors.lastname: Zhou
mesh_terms: D001419:Bacteria / Q000187:drug effects / Q000254:growth & development*; D001422:Bacterial Adhesion; D015921:Dental Implants / Q000382:microbiology*; D003775:Dental Polishing; D006801:Humans; D014025:Titanium / Q000737:chemistry* / Q000494:pharmacology
chemical_list: D015921:Dental Implants; D014025:Titanium