Horizontal Guided Bone Regeneration: L-PRF Bone-Block Vs A Mixture of Autogenous Bone with Deproteinized Bovine Bone Mineral. A Split-Mouth RCT Study with 25 Months Follow-Up

This study aims to assess the differences between a leukocyte- and platelet-rich fibrin (L-PRF) and deproteinized bovine bone mineral block and a combination of 50% autogenous bone (AB) and 50% deproteinized bovine bone mineral (DBBM) as grafting material for horizontal guided bone regeneration (GBR). This randomized double-blind split-mouth clinical trial included 13 subjects requiring bilateral horizontal bone augmentation. Each patient received both treatment modalities: one side of the jaw was treated by GBR with the L-PRF and deproteinized bovine bone mineral block, and the other side with a 50/50 mixture of AB and DBBM. Cone beam computed tomography (CBCT) scans were used to evaluate horizontal bone width (HBW) and buccal bone thickness (BBT) at various time points: baseline (T0), immediately post-augmentation (T1), at implant placement (T2), and one year after abutment connection (T4). Bone sounding (BS) was also used to verify CBCT measurements. No statistically significant differences were found in HBW gain between test (L-PRF) and control (AB/DBBM) sites at any timepoint. Both sites showed significant HBW loss post-implant placement, with more bone volume lost at higher crestal levels (Sh0 > Sh2 > Sh4). At the Sh2 level, 48.8% of the HBW gain at T1 was lost by T4 in test sites, and 46.2% 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. 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 post-implant placement. Further research with larger sample sizes is needed to confirm these findings and optimize GBR techniques.