title: Evaluation of primary stability of innovated orthodontic miniscrew system (STS): An ex-vivo study.
abstract: BACKGROUND
  Stability is determined as one of the requirements in use of Temporary Anchorage Devices (TAD) in orthodontics. Miniscrew has been a widely used Bone Anchor. Compared with mini-implant that necessitates osseointegration; mechanical retention is a determining factor for primary stability of miniscrew. Studies investigated various ways to increase primary stability. The aim of this study is to introduce a new configuration of miniscrew system which is believed to obtain more primary stability.
  
  
  METHODS
  Freshly ovine mandibles were cut in blocks. Twenty-seven miniscrews (diameter 1.6 × 8 mm; G2, Dual Top Anchor System, Jeil Medical, Seoul, Korea) were inserted in the blocks and divided in 2 experimental groups: single miniscrew and the innovated design "Seifi Twin Screw (STS)". Primary stability was evaluated by Periotest "M"® device.
  
  
  RESULTS
  Independent t-test showed a significant difference between 2 experimental groups in periotest evaluation (p< 0.05). STS demonstrated higher primary stability due to its mechanical configuration and design.
  
  
  CONCLUSIONS
  The STS provides higher primary stability and was found to be effective in increased success rate of miniscrew systems from the standpoint of primary stability.
  
  
  BACKGROUND
  Anchorage procedures, anchorage techniques, orthodontic anchorage procedures, miniscrews, temporary anchorage device.
authors.affiliation: DDS, MSD, MS Med Edu. Dentofacial Deformities Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Massoud
authors.initials: M
authors.lastname: Seifi
authors.affiliation: DDS. Department of Orthodontics, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
authors.forename: Negin-Sadat
authors.initials: NS
authors.lastname: Matini