Hounsfield unit comparison of grafted versus non-grafted extraction sockets.

Volumetric changes of the alveolar ridge after socket preservation with various techniques have been investigated frequently. However, changes in bone density and quality of bone within the extraction sockets have seldom been studied. The purpose of this study was to evaluate the bone quality of grafted versus non-grafted socket sites prior to dental implant placement using Hounsfield unit (HU) values derived from cone-beam computed tomography (CBCT) imaging. The data was collected from 39 healed extraction sites reviewed over a one-year period. Subjects eligible for the study had a bone replacement graft and barrier membrane. Both study and control groups had CBCT scans performed immediately after extraction and four to five months after extraction for planning implant placement. HU values were measured from the CBCT scans and compared between groups. Intragroup variability was assessed utilizing standard deviation and standard error of the mean. Intergroup differences were evaluated using unpaired t-test. A generalized lack of significant difference in bone quality was observed between groups with the only statistically significant difference observed in the posterior maxilla. Future radiographic and histologic assessments of bone quality after socket preservation are required to determine the 'ideal' approach to preserve an extraction socket prior to implant placement.