title: [Biomechanical comparison of self-drilling and self-tapping orthodontic micro-implants].
abstract: OBJECTIVE
  To evaluate the biomechanical influences of self-drilling and self-tapping methods on orthodontic micro-implants under immediate loading.
  
  
  METHODS
  Fifty-six micro-implants placed at the interradicular areas of buccal side of upper and lower jaws in two dogs were divided into self-drilling and self-tapping groups. A horizontal load of 1.96 N was immediately given for 9 weeks. Peak insertion torque and peak removal torque were tested immediately after implantation and after the dogs were killed, respectively.
  
  
  RESULTS
  Both in the upper and lower jaws peak insertion torque was significantly higher in self-drilling group [(5.6 +/- 1.1) N.cm and (8.7 +/- 2.3) N.cm] than in self-tapping group [(3.5 +/- 2.1) N.cm and (7.4 +/- 1.1) N.cm] (P < 0.05). Both in the upper and lower jaws peak removal torque was higher in self-drilling group [(-6.5 +/- 2.2) N.cm and (-7.1 +/- 2.0) N.cm] than in self-tapping group [(-5.7 +/- 2.3) N.cm and (-6.1 +/- 0.5) N.cm]. No significant difference was found (P > 0.05). The tendency of fracture was found in self-drilling group.
  
  
  CONCLUSIONS
  Self-drilling micro-implants have high initial stability and can be used in the maxilla and at thin cortical bone area of mandible.
authors.affiliation: Department of Orthodontics, School of Dentistry, Kyungpook National University, Daegu 700-412, Korea.
authors.forename: Yan
authors.initials: Y
authors.lastname: Chen
authors.forename: Wen-ting
authors.initials: WT
authors.lastname: Zhao
authors.forename: Hee-moon
authors.initials: HM
authors.lastname: Kyung
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D003799:Dental Stress Analysis; D004285:Dogs; D005260:Female; D052280:Orthodontic Anchorage Procedures / Q000295:instrumentation*; D019415:Torque
chemical_list: D015921:Dental Implants