title: Correlation of insertion torques with bone mineral density from dental quantitative CT in the mandible.
abstract: OBJECTIVE
  The aim of this study was to establish a correlation between bone mineral density measured preoperatively with dental computed tomography (CT), and insertion torque of screw-shaped dental implants.
  
  
  METHODS
  In eight human mandibles obtained postmortem, bone mineral density (BMD) was measured with dental quantitative CT (DQCT) and correlated with insertion torque values at 45 implant sites during insertion of screw-shaped dental implants (Brånemark System MKIII, Nobel Biocare, AB, Göteborg, Sweden).
  
  
  RESULTS
  A significant correlation (r=0.86, P<0.001) between BMD and torque values was observed, indicating that local BMD at a specific implant position is related to the supportive capacity of the jawbone. BMD exhibited no correlation with bone height or position.
  
  
  CONCLUSIONS
  The noninvasive assessment of BMD using a DQCT scan employing a low-dose protocol may be used to estimate expected primary stability depending on BMD, implant type and preparation procedure. These data may therefore help the surgeon to select the optimum implant position, implant type and operation technique.
authors.affiliation: Department of Biomedical Engineering and Physics, University of Vienna, Vienna, Austria.
authors.forename: Andreas
authors.initials: A
authors.lastname: Beer
authors.forename: André
authors.initials: A
authors.lastname: Gahleitner
authors.forename: Anders
authors.initials: A
authors.lastname: Holm
authors.forename: Manfred
authors.initials: M
authors.lastname: Tschabitscher
authors.forename: Peter
authors.initials: P
authors.lastname: Homolka
mesh_terms: D015502:Absorptiometry, Photon / Q000379:methods*; D015519:Bone Density; D003758:Dental Implantation, Endosseous; D015921:Dental Implants; D017268:Dental Prosthesis Retention; D003799:Dental Stress Analysis; D006801:Humans; D007575:Jaw, Edentulous / Q000000981:diagnostic imaging*; D008334:Mandible / Q000000981:diagnostic imaging; D010347:Patient Care Planning; D011379:Prognosis; D012044:Regression Analysis; D014057:Tomography, X-Ray Computed / Q000379:methods; D019415:Torque
chemical_list: D015921:Dental Implants