Allograft versus xenograft for alveolar ridge preservation in non-molar extraction sockets: a systematic review and meta-analysis of randomized controlled trials.

objectivesTo compare the clinical, radiographic, and histological outcomes of allograft and xenograft materials used for alveolar ridge preservation following non-molar tooth extraction through a systematic review and meta-analysis of randomized controlled trials. MATERIALS AND

methodsThis systematic review and meta-analysis was conducted in accordance with the PRISMA 2020 guidelines and registered in PROSPERO (CRD420261333947). Electronic searches of PubMed/MEDLINE, the Cochrane Central Register of Controlled Trials (CENTRAL), and ClinicalTrials.gov were performed through May 2026. Randomized controlled trials directly comparing allograft and xenograft materials for alveolar ridge preservation in non-molar extraction sockets were included. Risk of bias was assessed using the revised Cochrane Risk of Bias (RoB 2) tool. A qualitative synthesis and random-effects meta-analysis were performed where appropriate.

resultsSeven randomized controlled trials met the inclusion criteria, of which three were included in the meta-analysis. Both allograft and xenograft materials were associated with preservation of alveolar ridge dimensions following tooth extraction, although clinical and radiographic findings did not demonstrate a consistent advantage of either material. Histological findings suggested greater new bone formation, fewer residual graft particles, and faster graft remodeling with allografts, whereas xenografts were associated with slower resorption and greater persistence of residual graft particles. Meta-analysis demonstrated no statistically significant difference between allografts and xenografts in buccal height loss (SMD = - 0.177; 95% CI: -1.822 to 1.468; p = 0.833), with substantial heterogeneity (I² = 82%).

conclusionsCurrent evidence does not demonstrate a consistent clinical or radiographic superiority of either allograft or xenograft for alveolar ridge preservation following non-molar tooth extraction. Although biological differences in graft remodeling were observed, the limited number of studies, small sample size, and substantial heterogeneity reduce the certainty and precision of these findings. The absence of a statistically significant difference should not be interpreted as evidence of equivalence between the two materials. Further well-designed randomized controlled trials with standardized outcome measures and longer follow-up are needed to strengthen the available evidence. CLINICAL RELEVANCE: Available evidence does not demonstrate a consistent clinical or radiographic advantage of either allograft or xenograft for preservation of alveolar ridge dimensions following non-molar tooth extraction. The findings may assist clinicians in considering graft material selection for alveolar ridge preservation based on clinical requirements, while recognizing the limited and heterogeneous evidence and the absence of established superiority of either material.