title: Rotational resistance of surface-treated mini-implants.
abstract: OBJECTIVE
  To test the hypothesis that there is no difference in the stability and resistance to rotational moments of early loaded sandblasted and acid-etched (SLA) mini-implants and those of machined-surface implants of the same size and shape.
  
  
  METHODS
  A randomized complete block design was used in 12 skeletally mature male beagle dogs. Ninety-six orthodontic mini-implants were tested. Two types of implants were used: some had SLA surface treatment and some had machined surfaces without coating. After 3 weeks of healing, rotational moments of 150 g were applied. The success rates, maximum torque values, angular momentum, and total energy absorbed by the bone were compared. All values were subjected to mixed-model analysis to evaluate the influence of surface treatment, rotational force direction, and site of implantation.
  
  
  RESULTS
  The maximum insertion torque and angular momentum of SLA implants were significantly lower than those of machined implants (P = .034, P = .039). The SLA implants had a significantly higher value for total removal energy than the machined implants (P = .046). However, there were no significant differences in total insertion energy, maximum removal torque, and removal angular momentum between the 2 groups. There was no significant difference between clockwise and counterclockwise rotation in all measurements.
  
  
  CONCLUSIONS
  SLA mini-implants showed relatively lower insertion torque value and angular momentum and higher total energy during removal than the machined implants, suggesting osseointegration of the SLA mini-implant after insertion.
authors.affiliation: Department of Orthodontics, School of Dentistry and Dental Research Institute, Seoul National University, Jongro-Gu, Seoul, Korea.
authors.forename: Seong-Hun
authors.initials: SH
authors.lastname: Kim
authors.forename: Shin-Jae
authors.initials: SJ
authors.lastname: Lee
authors.forename: Il-Sik
authors.initials: IS
authors.lastname: Cho
authors.forename: Seong-Kyun
authors.initials: SK
authors.lastname: Kim
authors.forename: Tae-Woo
authors.initials: TW
authors.lastname: Kim
mesh_terms: D000818:Animals; D001863:Bone Screws; D045662:Dental Etching / Q000379:methods; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D003775:Dental Polishing; D019232:Dental Restoration Failure; D003799:Dental Stress Analysis; D020878:Device Removal; D004285:Dogs; D020007:Implants, Experimental; D008297:Male; D008904:Miniaturization; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D016348:Osseointegration; D011897:Random Allocation; D012399:Rotation; D013499:Surface Properties; D019415:Torque
chemical_list: D015921:Dental Implants