Horizontal Guided Bone Regeneration: L-PRF Bone Block Versus a Mixture of Autogenous Bone with Deproteinized Bovine Bone Mineral-A Split-Mouth RCT Study with a 25-Month Follow-up.

Purpose: To assess the differences between using leukocyte- and platelet-rich fibrin (L-PRF) with a deproteinized bovine bone mineral block versus a combination of 50% autogenous bone (AB) and 50% deproteinized bovine bone mineral (DBBM) as grafting material for horizontal guided bone regeneration (GBR).

Materials and methods: This randomized double-blind split-mouth clinical trial included 13 patients requiring bilateral horizontal bone augmentation. Each patient received both treatment modalities: one side of the jaw was treated via GBR with L-PRF and deproteinized bovine bone mineral block, and the other side was treated with a 50/50 mixture of AB and DBBM. CBCT scans were used to evaluate horizontal bone width (HBW) and buccal bone thickness (BBT) at the following time points: baseline (T0), immediately post-augmentation (T1), at implant placement (T2), and 1 year after abutment connection (T4). Bone sounding (BS) was also used to verify CBCT measurements.

Results: No statistically significant differences were found in HBW gain between test (L-PRF) and control (AB/DBBM) sites at any time point. Both sites showed significant HBW loss after implant placement, with more bone volume lost at higher crestal levels (at the implant shoulder level [Sh0], > 2 mm from the implant shoulder [Sh2], and > 4 mm from the implant shoulder [Sh4]). At the Sh2 level, 48.8% of the HBW gain at T1 was lost by T4 in test sites, and 46.2% of HBW gain was lost at the same time point in control sites. Similarly, BBT at Sh2 reduced from 4.7 ± 1.0 mm to 1.3 ± 1.5 mm in test sites and from 2.1 ± 1.0 mm to 0.9 ± 0.8 mm in control sites. Both groups of sites had one complication, resulting in a 91.6% success rate for both treatments. The cumulative survival rate of implants was 100% at 16 months, with a mean interproximal bone level (IBL) loss of 0.2 ± 0.9 mm and 0.1 ± 0.6 mm for test and control sites, respectively.

Conclusions: No statistically significant differences were found between the AB/DBBM composite graft and the L-PRF and bovine bone mineral block for horizontal GBR. Significant resorption of grafted volume occurs within 25 months, continuing after implant placement. Further research with larger sample sizes is needed to confirm these findings and optimize GBR techniques.