title: [A study on the stability of miniscrew  on different loading time as orthodontic anchorage].
abstract: OBJECTIVE
  To evaluate the stability of the miniscrew on different loading time as orthodontic anchorage.
  
  
  METHODS
  2 healthy adult male Beagle dogs were used in this study. 48 mini-implants were implanted into the maxilla and mandible of the dogs. The miniscrews were divided into 8 different groups,1 group was loaded 0g as control group and the others were loaded 200g forces as experimental groups. 200g forces were loaded on the corresponding mini-implant anchorages immediately after implantation and at the time of 1w,2w,3w,4w,5w and 6w after implantation. The dogs were sacrificed at 12w after implantation. Histological progresses of implant-bone interfaces was examined with light microscope. Blue deposition and contact ratio were calculated and analyzed using SPSS13.0 software package.
  
  
  RESULTS
  Fibrous and osseous-integration was noted in the interface, there was no significant difference in bone deposition ratio and bone contact ratio.
  
  
  CONCLUSIONS
  Different force loading time does not affect the stability of the mini-implant anchorage.
authors.affiliation: Department of Stomatology, Ruijin Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China. zliangyan@gmail.com
authors.forename: Liang-yan
authors.initials: LY
authors.lastname: Zhu
authors.forename: Yong-qing
authors.initials: YQ
authors.lastname: Yan
authors.forename: Yi-ming
authors.initials: YM
authors.lastname: Gao
mesh_terms: D000818:Animals; D001863:Bone Screws; D004285:Dogs; D008297:Male; D008334:Mandible; D008437:Maxilla; D052280:Orthodontic Anchorage Procedures; D016348:Osseointegration