Clinical Outcomes of rhBMP-2-Loaded Collagen Sponge for Alveolar Ridge Preservation: A Pilot Study

Alveolar bone resorption following tooth extraction poses a significant clinical challenge. While various ridge preservation techniques exist, limitations remain. Recombinant human bone morphogenetic protein-2 (rhBMP-2) delivered via an absorbable collagen sponge (ACS) has shown promise in bone augmentation. This pilot randomized controlled trial aimed to evaluate the efficacy of ACS combined with rhBMP-2 for alveolar ridge preservation in maintaining ridge dimensions after tooth extraction.

This pilot randomized controlled trial enrolled 11 participants with 16 extraction sites, randomized to either the intervention (ACS/rhBMP-2) or the control (empty socket) group. The in vitro release kinetics of rhBMP-2 from the ACS carrier were measured over 13 days using ELISA (enzyme-linked immunosorbent assay). Clinical procedures involved atraumatic extraction, followed by the placement of ACS/rhBMP-2 in the intervention group. Alveolar ridge dimensions were assessed using cone-beam computed tomography at baseline (T0), and at 4 (T4), 8 (T8), and 12 weeks (T12) post-extraction.

Data were presented as mean ± standard deviation. A linear mixed model was used to compare dimensional changes over time between the two groups. A p-value of <0.05 was considered statistically significant.

The in vitro assay showed a gradual, sustained release of rhBMP-2 from the ACS, with a cumulative release of 7.28% (117 ± 5.18 µg) over 13 days. No postoperative complications were observed in any participant. At 12 weeks, the ACS/rhBMP-2 group demonstrated a statistically significant preservation of buccal bone height, with 1.80 mm less vertical reduction compared to the control group. No significant differences were found between groups for palatal/lingual bone reduction or for changes in the overall bucco-lingual ridge width.

The application of ACS combined with rhBMP-2 is an effective approach for mitigating buccal bone resorption after tooth extraction. This intervention is clinically significant as it preserves critical buccal plate height, potentially reducing the need for further augmentation prior to implant placement, even though it does not prevent overall ridge width collapse.