title: Histomorphometric and biomechanical analyses of the osseointegration of loaded orthodontic microscrews inserted at different cortical bone thickness sites.
abstract: OBJECTIVE
  The aim of this study was to evaluate the osseointegration of loaded orthodontic microscrews at different cortical bone thickness (CBT) sites.
  
  
  METHODS
  Forty-eight microscrews were inserted bilaterally in the tibias of 12 beagles, and divided into thick and thin CBT group. After 1, 3, 5, and 7 weeks, the dogs were killed and bone-screw specimens prepared for polyfluorochrome sequential labeling, microscopic computerized tomography (μCT) analysis, and biomechanical pull-out testing.
  
  
  RESULTS
  All μCT parameters were increased in the thin CBT group, and decreased in the thick CBT group with time passed. Fmax of microscrews in thick CBT sites reached a peak in week 1, but dropped to lowest levels in week 3. Remodeling, apposition, and measured deposition areas of 3 labels were significantly higher in the thin CBT group than in the thick CBT group (P < .05).
  
  
  CONCLUSIONS
  Relatively larger CBT is of benefit for primary stability at early time points, whereas thinner CBT is more appropriate for achieving long-term stability with prolonged time.
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Zhenrui
authors.initials: Z
authors.lastname: Xu
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Lixing
authors.initials: L
authors.lastname: Zhao
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Yeke
authors.initials: Y
authors.lastname: Wu
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Wei
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Jue
authors.initials: J
authors.lastname: Wang
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Na
authors.initials: N
authors.lastname: Tang
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China.
authors.forename: Tian
authors.initials: T
authors.lastname: Tang
authors.affiliation: Department of Orthodontics, State Key Laboratory of Oral Diseases, West China School of Stomatology, Sichuan University, Chengdu, China. Electronic address: zhzhao@scu.edu.cn.
authors.forename: Zhihe
authors.initials: Z
authors.lastname: Zhao
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D001863:Bone Screws; D020878:Device Removal; D004285:Dogs; D020007:Implants, Experimental; D052280:Orthodontic Anchorage Procedures / Q000379:methods*; D016348:Osseointegration; D013977:Tibia / Q000601:surgery; D055114:X-Ray Microtomography