Introduction Following tooth extraction, alveolar bone resorption—particularly in the buccal-lingual dimension—is a well-documented phenomenon. Alveolar ridge preservation (ARP) is commonly performed to maintain ridge volume for future implant placement. While various materials and techniques are available for ARP, the optimal choice of membrane in cases with an intact buccal plate remains inconclusive. This study aims to evaluate the dimensional changes in hard and soft tissues and to perform histological analysis following ARP using different membrane types.

Materials and Methods 51 subjects with premolar extraction sites were randomized into five groups, each receiving alveolar ridge preservation with a 1:1 allograft–xenograft mixture and one of the following membranes: absorbable collagen dressing (ACD), non-resorbable d-PTFE (d-PTFE), cross-linked collagen membrane (CLCM), non-cross linked ECM membrane (N-CLCM), or dehydrated human deepithelialized amnion-chorion membrane (DHDA-C). Pre-extraction intraoral scans (Pre-STL) and cone beam computed tomograms (Pre-CBCT) were obtained. Four months after extraction, Post-STLs and Post-CBCTs were taken. Comparison of the pre- and post-extraction scans was performed to determine horizontal alveolar and soft tissue dimensional changes using a standardized Region of Interest (ROI) guide. Five months post-extraction, implants were placed and bone cores harvested using trephine drills guided by surgical stents. Histological analysis was conducted to evaluate tissue quality and graft integration across membrane groups.

Results Of 80 patients enrolled, 48 (54 sites) were included for hard tissue and 27 (27 sites) for soft tissue analysis. ANOVA showed no statistically significant differences in total horizontal ridge dimensional changes (p = 0.741) or crestal region changes (p = 0.875) among membrane groups. Soft tissue analysis revealed no significant differences among groups (p = 0.389). Histological analysis (n = 36 patients, 40 sites) showed no significant differences in total bone percentage (p = 0.058) or residual allograft (p = 0.337), but significant differences in new bone formation (p = 0.008) and residual xenograft (p = 0.007). CLCM demonstrated superior new bone formation compared to ACD (p = 0.018).

Conclusion All membrane types demonstrated comparable effectiveness in preserving ridge dimensions in intact sockets, with no significant differences in hard or soft tissue outcomes. However, CLCM showed superior new bone formation compared to ACD. Since no membrane completely prevented ridge resorption, membrane selection should be based on clinician preference, handling characteristics, and patient- specific factors. Larger studies are needed to confirm these findings and explore the clinical significance of histological differences.