Alveolar ridge preservation versus unassisted socket healing following tooth extraction: a systematic review of controlled clinical studies and meta-analysis of randomised trials.

Abstract

Purpose: To estimate early horizontal ridge-width and explicit buccal/facial vertical hard-tissue loss after alveolar ridge preservation (ARP) versus unassisted socket healing.

Methods: The review was registered in PROSPERO (CRD420261432689). PubMed/MEDLINE, Scopus, Web of Science Core Collection, Embase.com, and ClinicalTrials.gov were searched on 24 June 2026; CENTRAL provided supplementary verification on 1 July 2026. Two reviewers independently selected reports. One reviewer extracted data; the second verified classifications and effect inputs. Randomised direct comparisons were pooled using REML random-effects models with Hartung-Knapp inference. Risk of bias and certainty were assessed with RoB 2 and GRADE.

Results: Of 1,864 records, 1,739 were screened, and 62 underwent full-text assessment. 28 direct comparison reports were eligible; 20 randomised studies contributed quantitatively, and 8 reports were narrative-only. ARP was associated with less horizontal ridge-width loss (k = 18; MD - 1.37 mm, 95% CI - 1.80 to - 0.94; I² = 75.9%; prediction interval - 2.86 to 0.12) and less explicit buccal/facial vertical loss (k = 13; MD - 1.18 mm, 95% CI - 1.61 to - 0.75; I² = 74.3%; prediction interval - 2.54 to 0.17). Certainty was low for both. The exploratory broad vertical/buccal synthesis favoured ARP (k = 16; MD - 1.26 mm, 95% CI - 1.63 to - 0.89) with very low certainty.

Conclusion: ARP may reduce early dimensional loss, but substantial heterogeneity and prediction intervals including no effect limit generalisability. Evidence does not establish universal indications, intervention superiority, or long-term implant, aesthetic, or patient-reported benefit.