title: Assessments of jaw bone density at implant sites using 3D cone-beam computed tomography.
abstract: OBJECTIVE
  To assess the bone density of dental implant sites using CBCT and Simplant software, and establish a quantitative ranges for each bone quality classification according to the classification of bone quality proposed by Lekholm and Zarb.
  
  
  METHODS
  128 patients' jaw bone were scanned by CBCT, the images were reconstructed by the Simplant software. The bone density of 236 potential implant sites was measured and the results were recorded using Hounsfield units (HU)．The data was analyzed with SPSS 19.0 software package for Mann-Whitney U test.
  
  
  RESULTS
  The anterior mandible mean bone density was (679.6 ± 141.67) HU > anterior maxilla, (460.25 ± 136.42) HU and posterior mandible, (394.4 ± 128.37) HU > posterior maxilla, (229.62 ± 144.48) HU. Quantitative parameters ranged of the bone density according to CBCT as follows: Lekholm and Zarb classification Type D4 was less than 200 HU, Type D2 and Type D3 were more than 200HU and less than 600 HU, and Type D1 was more than 600 HU.
  
  
  CONCLUSIONS
  Anterior mandible has the highest mean bone density and posterior maxilla has the lowest mean bone density．It is, therefore, proposed that an objective classification which confirms the importance of a site-specific bone tissue evaluation prior to implant installation.
authors.affiliation: Department of Stomatology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, People's Republic of China. derongzou@gmail.com.
authors.forename: Y
authors.initials: Y
authors.lastname: Hao
authors.forename: W
authors.initials: W
authors.lastname: Zhao
authors.forename: Y
authors.initials: Y
authors.lastname: Wang
authors.forename: J
authors.initials: J
authors.lastname: Yu
authors.forename: D
authors.initials: D
authors.lastname: Zou
mesh_terms: D000328:Adult; D015519:Bone Density; D054893:Cone-Beam Computed Tomography; D003757:Dental Implantation / Q000295:instrumentation*; D015921:Dental Implants; D005260:Female; D006801:Humans; D021621:Imaging, Three-Dimensional; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging* / Q000601:surgery*; D008437:Maxilla / Q000000981:diagnostic imaging* / Q000601:surgery*; D008875:Middle Aged; D018579:Patient Selection; D011237:Predictive Value of Tests; D011300:Preoperative Care; D011857:Radiographic Image Interpretation, Computer-Assisted; D012984:Software
chemical_list: D015921:Dental Implants