Rethinking graft materials for guided bone regeneration: insights from a pilot randomised controlled trial

Rao S, Zhou J, Niu W, Dong C, Pan S, Sun W. Partially demineralised allogeneic cancellous bone plug versus deproteinized bovine bone mineral for guided bone regeneration: a pilot randomised controlled clinical trial. Clin Oral Investig. 2026;30:228. https://doi.org/10.1007/s00784-026-06914-8 .

The present pilot randomised controlled clinical trial (RCT) evaluated the regenerative potential of a partially demineralised allogeneic cancellous bone plug (ACBP) by comparing it with deproteinized bovine bone mineral (DBBM) for guided bone regeneration (GBR).

The authors included 25 adults aged 18-65 years requiring GBR before implant placement and randomly allocated them to ACBP (n = 12) or DBBM (n = 13). The selected sites included posterior mandibular extraction sockets with horizontal defects >5 mm and 3- or 4-wall defects, and maxillary posterior sites with remaining bone height <5 mm that needed lateral-window sinus floor elevation. Post 6 months before implant placement, CBCT assessment was done to measure bone dimensions, and 3-mm trephine bone biopsies were collected for histological and histomorphometric assessment.

Histomorphometric analysis of RG% and VB% was conducted on H&E-stained 3-mm bone core biopsies, while CBCT assessed bone dimensional changes in the sinus floor elevation and socket preservation subgroups. Statistical analysis was performed using SPSS 25.0; normality was assessed using the Shapiro-Wilk test, and between-group comparisons used independent-samples or Welch's t-tests, as appropriate. Exploratory ANCOVA adjusted 6-month sinus height gain for baseline residual subantral bone height. Statistical significance was set at two-sided P < 0.05.

Both ACBP and DBBM groups did not show statistically significant differences in terms of regenerative and dimensional outcomes, except that at 6 months RG% was less in ACBP when compared to DBBM. Histologic and Histomorphometric evaluation showed no significant difference in newly formed VB% between ACBP and DBBM (38.84 ± 8.37% vs 32.18 ± 11.04%; P = 0.105), however, RG% remained significantly lower in the ACBP group (11.18 ± 5.48% vs 19.80 ± 8.23% in the DBBM group, with P = 0.006). Whereas in the sinus floor elevation subgroup after 6 months, mean height gain was non-significant between the groups (7.82 ± 1.52 mm in ACBP vs 8.21 ± 4.30 mm in DBBM, with P = 0.852), and the difference in 6-month augmented bone height remained non-significant after adjustment for baseline residual subantral bone height (P = 0.801). In the extraction socket preservation subgroup, changes in ridge height and width at 8, 10, and 12 mm after 6 months were also not significantly different between groups (P > 0.05).

The present RCT indicates that ACBP, a relatively less established grafting material, did not demonstrate statistically significant differences from the widely used and well-documented DBBM for most regenerative and dimensional outcomes, except for a lower residual graft fraction at the ACBP site after 6 months. These findings provide preliminary evidence regarding the potential of ACBP in guided bone regeneration. However, further multicentre studies, larger sample sizes, longer follow-up, and indication-specific evaluation are required to establish its long-term clinical effectiveness and applicability.