title: A healing period increases mini-implant stability in growing rats.
abstract: We assessed the stability of orthodontic mini-implants in young rats. Male rats with mean ages of 6 weeks (n = 16) and 20 weeks (n = 16) were divided into four groups (n = 8 each). In the 6- and 20-week immediate-loading groups, immediately after placement, mini-implants were exposed to an experimental traction force for 2 weeks. In the 6- and 20-week healing groups, the force was applied for 2 weeks after a 6-week healing period. Right tibiae served as the test limbs and the left tibiae as controls. A Periotest device was used to measure mini-implant mobility after traction, and Tukey's test was used to compare Periotest values among groups. The results showed significantly greater mobility in the 6-week immediate-loading group than in the 20-week immediate-loading and 6- and 20-week healing groups, and significantly less mobility in the 6-week healing group than in the 20-week immediate-loading group (P < 0.05). Mini-implants were stable during the healing period. The results indicate that mini-implants can be used for orthodontic anchorage in juvenile patients if the duration of healing is sufficient.
authors.affiliation: Department of Orthodontics, Nihon University School of Dentistry.
authors.forename: Shinya
authors.initials: S
authors.lastname: Yano
authors.forename: Mitsuru
authors.initials: M
authors.lastname: Motoyoshi
authors.forename: Mizuki
authors.initials: M
authors.lastname: Inaba
authors.forename: Saori
authors.initials: S
authors.lastname: Yano
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Takenouchi
authors.forename: Seil
authors.initials: S
authors.lastname: Son
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Arai
authors.forename: Noriyoshi
authors.initials: N
authors.lastname: Shimizu
mesh_terms: D000818:Animals; D008297:Male; D019736:Prostheses and Implants; D051381:Rats; D017208:Rats, Wistar; D013977:Tibia / Q000000981:diagnostic imaging / Q000473:pathology*; D014945:Wound Healing; D055114:X-Ray Microtomography