title: [Influence of the peri-implantitis to the microscrew-bone interface].
abstract: OBJECTIVE
  To study the histological change of microscrew-bone interface, detect the relative cytokine of gingival crevicular fluid, and explore the impossible mechanism of peri-implantitis.
  
  
  METHODS
  Four male Beagles were collected. Randomly select one side of animals jaw as the experimental group to induce the peri-implantitis, and another side as the control group. Four microscrews were implanted on each side. In the 1st, 2nd, 3rd, 4th weeks after implantation, collect peri-implant sulcular fluid (PISF) and detect tumor necrosis factor-alpha (TNF-alpha) levels before sacrificed, and the harvest tissue were observed in histological ways.
  
  
  RESULTS
  According to the extension of time after implantation, the experimental group showed visible progress of interface destruction: 1st week after implantation showed large numbers inflammatory cells collected at the neck but did not undermine the cortical bone; 2nd week after implantation, cortical bone were observed angular absorption; Bone resorption continued to develop and at the 4th week, bone resorption were enlarged to the second thread of microscrew and the interface was filled with a large number of collagen fibers.
  
  
  CONCLUSIONS
  The destruction of interface began at the neck of microscrew, and the further development was along the interface in depth. Both microscrews with peri-implantitis and the healthy controls showed the presence of TNF-alpha. Inflammation accumulation might trigger the up-regulation of TNF-alpha level, and the onset of inflammation would enhance the up-trend.
authors.affiliation: Dept. of Preventive and Pediatric Dentistry, The Affiliated Stomatology Hospital, Chongqing Medical University, Chongqing 400015, China.
authors.forename: Yun
authors.initials: Y
authors.lastname: Hu
authors.forename: Lei-le
authors.initials: LL
authors.lastname: Zheng
authors.forename: Tian
authors.initials: T
authors.lastname: Tang
authors.forename: Zhi-he
authors.initials: ZH
authors.lastname: Zhao
authors.forename: Jin-lin
authors.initials: JL
authors.lastname: Song
authors.forename: Feng
authors.initials: F
authors.lastname: Deng
mesh_terms: D000818:Animals; D001842:Bone and Bones; D015921:Dental Implants; D004285:Dogs; D005883:Gingival Crevicular Fluid; D008297:Male; D057873:Peri-Implantitis; D014409:Tumor Necrosis Factor-alpha
chemical_list: D015921:Dental Implants; D014409:Tumor Necrosis Factor-alpha