Evaluation of primary stability of innovated orthodontic miniscrew system (STS): An ex-vivo study

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. MATERIAL AND 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. KEY WORDS Anchorage procedures, anchorage techniques, orthodontic anchorage procedures, miniscrews, temporary anchorage device.