[Jaw bone density assessments of implant sites using spiral CT and Simplant software].

PURPOSE:To assess the bone density of dental implant sites using spiral CT and simplant software, and classify them by Lekholm and Zarb grouping. METHODS:53 patients' jaw bone were scanned by spiral CT, the scanned images were reconstructed by the Simplant software.The bone density of 136 designed implant sites was measured and the results were recorded using Hounsfield units(HU).The data was analyzed with SPSS11.0 software package for Mann-Whitney U test, and classified by Lekholm and Zarb grouping. RESULTS:The mean bone density in all implant sites was (714.66+/-273.72) HU.The anterior mandible mean bone density was (962.96+/-92.21)HU>anterior maxilla, (786.15+/-188.74) HU>posterior mandible, (785.79+/-290.91) HU>posterior maxilla, (569.67+/-244.34)HU. Bone class IV was least in anterior mandible and most in posterior maxilla(P<0.01), accounting for 26.5% in all implant sites. CONCLUSIONS:Anterior mandible has the highest mean bone density and posterior maxilla has the lowest mean bone density. There are class I and II/III in most of the implant sites. Spiral CT is a useful tool for determining the bone density, which is important for preoperative design and postoperative assessment.