title: Mechanical properties of three different commercially available miniscrews for skeletal anchorage.
abstract: BACKGROUND
  During the last 5 years, anchorage control with self-tapping miniscrews has become an important part of the clinical management of orthodontic patients. Yet, no studies have been performed for measuring mechanical properties of the currently available systems.
  
  
  OBJECTIVE
  The purpose of this study is the evaluation of mechanical properties of three commercially available self-tapping screw systems used in orthodontic treatment.
  
  
  METHODS
  three systems with a 1.5 mm diameter and 11 mm length screw (Leone, Firenze, Italy; M.A.S. Micerium, Avegno, Italy; Dentos, Korea) were examined. The results compared the resistance to bending, torque, pullout of each screw and the insertion moments needed to screw down each sample.
  
  
  CONCLUSIONS
  All three miniscrews have mechanical properties that contribute to their safe use as skeletal anchorage in orthodontics. Although stainless steel has demonstrated to be more resistant to failure than titanium, its overall performance as material for miniscrews could be inferior to titanium. In order to facilitate the insertion, the asymmetric profile of the thread should be preferred to the symmetric cut. The ratio between the diameter of the drill and the diameter of the corresponding miniscrew is pivotal for the successful implantation and resistance of the miniscrews. Looking at the mechanical properties evaluated in this study, a cylindric shape of the screw is better than a conic one. The conic shape could be preferred in case the site of insertion is iterradicular and therefore limited to 2.5-3.5 millimetres.
authors.affiliation: Department of Orthodontics, University of Ferrara, Ferrara, Italy.
authors.forename: Aldo
authors.initials: A
authors.lastname: Carano
authors.forename: Pietro
authors.initials: P
authors.lastname: Lonardo
authors.forename: Stefano
authors.initials: S
authors.lastname: Velo
authors.forename: Cristina
authors.initials: C
authors.lastname: Incorvati
mesh_terms: D001863:Bone Screws; D003722:Dental Alloys; D003758:Dental Implantation, Endosseous / Q000379:methods; D003799:Dental Stress Analysis; D016382:Orthodontic Appliance Design; D009967:Orthodontic Appliances; D018583:Pliability; D013193:Stainless Steel; D014025:Titanium; D019415:Torque
chemical_list: D003722:Dental Alloys; D013193:Stainless Steel; D014025:Titanium