Comparing the histological assessment following ridge preservation using a composite bovine-derived xenograft versus an alloplast hydroxyapatite-sugar cross-linked collagen matrix

Background: This randomized controlled trial was designed to evaluate the histological wound healing and alveolar ridge dimensional changes following ridge preservation using two different xenograft/collagen matrices. Methods: Fifty-four patients each with non-molar teeth that required extraction and replacement with dental implants were enrolled. Teeth extractions were completed with minimal flap reflection and were randomized to receive ridge preservation with either 90% bovine-derived xenograft granules in a 10% porcine collagen matrix (Group A) or a sponge-like matrix of 80% microparticulate hydroxyapatite alloplast graft with 20% sugar cross-linked porcine type 1 collagen (Group B). After 16 weeks of healing and at the time of implant placement, a bone core biopsy was harvested followed by dental implant placement. The primary histological outcome evaluated were percentage of vital bone formation and connective tissue/other (fibrous tissue and marrow space). Secondary outcomes included the change in alveolar ridge width and the buccal and lingual ridge height. Statistical analysis was completed with two-sample t-test and Fisher exact test. Results: Forty-four patients completed the study, 23 in group A and 21 in group B. Group B presented with statistically significantly (p = 0.02) more percentage of vital bone (39.3 ± 17.8) than group A (26.8 ± 15.8). No statistically significant difference was observed for changes in alveolar ridge dimensions. Conclusions: Group B, when used for ridge preservation, yields statistically significantly more vital bone over a 4-month healing period. Ridge dimension changes were similar between the two groups and were adequate for implant placement.