Ridge Preservation With or Without an Osteoinductive Allograft: A Clinical, Radiographic, Micro-Computed Tomography, and Histologic Study Evaluating Dimensional Changes and New Bone Formation of the Alveolar Ridge

Background: The aim of this randomized, controlled clinical trial is to determine whether ridge preservation using an osteoinductive allograft (test) would prevent ridge resorption and promote bone maturation compared to extraction alone (control). Methods: Seventeen patients (20 total sites), in need of a non-molar extraction and delayed implant placement were randomly selected to receive either ridge preservation or extraction alone. A cone-beam computed tomography was completed with a radiographic stent in place before extraction and 10 to 12 weeks postoperatively for dimensional and buccal plate analyses. Bone cores were taken for micro-computed tomography (microCT) and histologic analyses. Results: Resorption of the alveolar ridge occurred at all sites with no statistically significant differences found between test and control sites. A significant correlation was found between the initial buccal plate thickness and the loss of vertical ridge height. microCT and histologic analyses found a mean new bone volume of 44.9% with microCT and 37.4% with histology in test sites and 39% and 35.5%, respectively, in control sites. The residual graft volume was 2.4% with microCT and 4.5% with histology. Conclusions: Test and control sites lost similar amounts of alveolar ridge, with the loss of buccolingual width occurring predominately at the expense of the buccal bone. A thicker buccal plate was associated with less ridge loss in the vertical dimension. The percentage of new bone was not statistically significant between either the test or control sites, using either microCT or histologic analyses. J Periodontol 2012;83:581-589.