Allogeneic bone plug vs DBBM for GBR: comparable bone, faster turnover in pilot RCT

Selecting the right biomaterial for guided bone regeneration remains a clinical decision with substantial impact on outcomes. This prospective randomized controlled trial compared a partially demineralized allogeneic cancellous bone plug (ACBP) with deproteinized bovine bone mineral (DBBM) — the current workhorse — across two common indications: posterior maxillary sinus floor elevation and mandibular posterior extraction socket preservation.

Twenty-five patients were randomized to ACBP (n=12) or DBBM (n=13), both covered with collagen membranes. CBCT was obtained at baseline and 6 months, and a 3-mm trephine core was harvested at implant placement for histomorphometric analysis.

Vital bone fraction did not differ significantly between groups (ACBP: 38.84 ± 8.37% vs DBBM: 32.18 ± 11.04%, P=0.105). However, residual graft material was significantly lower with ACBP (11.18 ± 5.48% vs 19.80 ± 8.23%, P=0.006). CBCT-based dimensional outcomes were comparable: sinus height gain was similar (7.82 ± 1.52 mm vs 8.21 ± 4.30 mm, P=0.852), and ridge dimensional changes at socket sites showed no differences.

The key interpretation: the lower residual graft fraction with ACBP, combined with equivalent vital bone and dimensional stability, points to faster graft turnover rather than superior bone formation. This is clinically relevant — at routine 6-month implant timing, ACBP leaves less residual material while maintaining the volume needed for implant placement. For clinicians choosing between allogeneic and xenogeneic bone substitutes, these results suggest that ACBP is a viable alternative to DBBM for both sinus elevation and socket preservation.