Healing at Molar Extraction Sites Using Freeze-Dried Bone Allograft and Collagen Wound Dressing: Case Series and Three-Arm Analyses

Purpose: Ridge preservation limits dimensional changes after tooth extraction. However, it is still unclear if using a membrane may be advantageous over a collagen wound dressing. Therefore, the goal of this report was to evaluate the outcomes of ridge preservation using freeze-dried bone allograft with a collagen wound dressing. Materials and Methods: This study included 21 patients who had one molar extracted, and the site received ridge preservation using freeze-dried bone allograft and a collagen wound dressing (test 2 group). Patients had two standardized cone beam computed tomography (CBCT) scans, taken within 72 hours and 3 months after extraction, to measure changes in ridge height and width, and buccal and lingual plate thicknesses. Changes in keratinized tissue width were recorded. Three-arm analyses were performed using historic data from a previous randomized controlled trial by the same study group, in which 20 molar sites received a collagen wound dressing alone (control) and 20 received ridge preservation with freezedried bone allograft and a dense polytetrafluoroethylene membrane (test 1) using the same methodology. Results: There was a statistically significant difference in mean buccal ridge height changes between the control group (2.6 ± 2.06 mm) and test 2 group (1.55 ± 0.93 mm) but no difference in ridge and keratinized tissue width changes between groups. No correlation was found between buccal plate thickness and ridge width change. Conclusion: Freeze-dried bone allograft with collagen wound dressing as a barrier was used successfully for ridge preservation in intact molar extraction sites ( 50% bone loss) and can be considered as a treatment alternative to freeze-dried bone allograft with a dense polytetrafluoroethylene membrane. Keywords: allografts, bone, cone beam computed tomography, dental implants, molar, tooth extraction