Interproximal Soft Tissue Height Changes After Unassisted Socket Healing vs Alveolar Ridge Preservation Therapy

The primary aim of this study was to evaluate the efficacy of alveolar ridge preservation (ARP) ther- apy compared with unassisted socket healing (USH) in attenuating interproximal soft tissue atrophy. Adult patients who underwent maxillary single-tooth extraction with or without ARP therapy were included. Surface scans were obtained and CBCT was performed to digitally assess interproximal soft tissue height changes and measure facial bone thickness (FBT), respectively. Logistic regres- sion models were conducted to investigate the individual effect of demographic and clinical vari- ables. Ninety-six subjects (USH = 49; ARP = 47) constituted the study population. Linear soft tissue assessments revealed a significant reduction of the interproximal soft tissue over time within and between groups (P < .0001). ARP therapy significantly attenuated interproximal soft tissue height re- duction compared to USH: –2.0 ± 0.9 mm mesially for USH vs –1.0 ± 0.5 mm mesially for ARP; –1.9 ± 0.7 mm distally for USH vs –1.1 ± 0.5 mm distally for ARP (P < .0001). Thin (≤ 1 mm) facial bone thick- ness (FBT) upon extraction was associated with greater interproximal soft tissue atrophy compared to thick FBT (> 1 mm), independent of the treatment received (P < .0001). Nevertheless, ARP therapy resulted in better preservation of interproximal soft tissue height, especially in thin bone phenotype, by a factor of 2 for the mesial site (+1.3 mm) and by a factor of 1.6 for the distal site (+0.9 mm). This study demonstrated that ARP therapy largely attenuates interproximal soft tissue dimensional re- duction after maxillary single-tooth extraction compared to USH.