Role of Defect Morphology in Alveolar Ridge Preservation: An Experimental In Vivo Investigation

This study aimed to assess the bone healing capacity of 1-, 2-, and 3-wall defects after alveolar ridge preservation (ARP) and to determine the effectiveness of ARP in managing compromised extraction sites. Eight beagle dogs were used, with three defect types (1-, 2-, and 3-wall) randomly assigned to the maxillary second, third, and fourth premolars. Each defect was created at either the mesial or distal root of a hemi-sectioned tooth, with the opposing root retained to allow histomorphometric comparison. Sites were randomly treated with either spontaneous healing (SH, control) or ARP (intervention). Each defect group was further divided for healing periods of four or twelve weeks. Histomorphometric data were analyzed using the Mann-Whitney U and Kruskal-Wallis tests, with significance set at P<0.05. Qualitative evaluation indicated greater new bone formation in the apical region than in the coronal region across all defect types and healing intervals. Quantitatively, 3-wall defects in the ARP group showed significantly higher mineralization after 12 weeks (ARP: 61.73% ± 7.52%; SH: 48.84% ± 3.06%; P=0.029). Although a trend of increased mineralization was noted with more residual bony walls, this did not reach statistical significance. Within the study’s constraints, ARP promoted a higher degree of mineralization in compromised extraction sites compared to spontaneous healing. While the influence of remaining bony walls was modest, their presence appeared to enhance mineralization outcomes in ARP-treated defects.