Histologic Comparison of Healing Following Tooth Extraction With Ridge Preservation Using Two Different Xenograft Protocols

Background: The objectives of this study are to compare differences in histologic and clinical healing following tooth extraction and ridge preservation using two different xenograft treatment protocols. Methods: Forty‐four patients with a non‐molar tooth that required extraction and planned implant placement were randomly allocated into two ridge preservation protocol groups. Protocol 1 used a xenograft material consisting of 90% anorganic bovine bone in combination with 10% porcine collagen fibers combined with a resorbable bilayer membrane composed of non‐cross‐linked porcine types I and III collagen. Protocol 2 used a xenograft sponge composed of 70% cross‐linked type I bovine collagen coated with a layer of non‐sintered hydroxyapatite mineral on its surface combined with a resorbable membrane composed of type I porcine collagen cross‐linked by natural ribose glycation. Following 21 weeks of healing, clinical measurements were repeated, and a core biopsy was obtained and prepared for histologic evaluation of percentages of vital bone, residual graft, and connective tissue/other (CT/other). Results: Similar percentages of CT/other were detected between protocols, with no significant difference between groups (P = 0.763). A significantly greater percentage of vital bone was detected in specimens in protocol 2 (P