Effect of the socket shield technique on alveolar ridge dimensional changes in sites with thin buccal bone phenotype: A randomized clinical trial.

Abstract

Background: Post-extraction alveolar ridge remodeling is a major challenge for implant therapy, particularly in sites with a thin buccal bone phenotype. Although immediate implant placement has been proposed to limit ridge resorption, buccal dimensional changes remain frequent. The socket shield technique has been proposed to preserve the periodontal ligament-bundle bone complex and reduce post-extraction bone loss. This randomized clinical trial aimed to compare alveolar ridge dimensional changes following the socket shield technique versus immediate implant placement in sites with buccal bone thickness <1.5mm.

Materials and methods: This parallel-arm randomized controlled clinical trial included patients requiring extraction of a single-rooted tooth and presenting a thin buccal bone phenotype (BBT <1.5mm). Participants were randomly allocated to receive either socket shield technique (SST) or immediate implant placement (IIP). Horizontal, vertical, and volumetric alveolar ridge changes were assessed using CBCT superimposition at baseline and 1 year. Marginal bone levels were evaluated at implant placement, prosthetic loading, and 1-year follow-up using standardized periapical radiographs. Intergroup comparisons were performed using analysis of covariance (ANCOVA) adjusting for baseline values.

Results: Forty patients completed the study. The SST group demonstrated significantly lower horizontal ridge reduction and buccal vertical bone loss compared with the IIP group at all evaluated levels (p<0.001). Volumetric analysis demonstrated significantly greater overall bone loss in the IIP group (p<0.001). Marginal bone loss did not differ between groups at implant placement; however, significantly greater marginal bone loss progression was observed in the IIP group at prosthetic loading and 1-year follow-up (p<0.001).

Conclusions: In extraction sites presenting a thin buccal bone phenotype, the socket shield technique significantly reduced horizontal and buccal vertical ridge resorption, limited volumetric bone loss, and resulted in improved marginal bone stability compared with immediate implant placement. These findings suggest that SST may represent a predictable strategy for preserving peri-implant hard tissues in anatomically compromised sites.