Defect-Adapted Guided Bone Regeneration of the Atrophic Edentulous Maxilla Using a PRGF-Enriched Autogenous Bone/ABBM Composite: A Prospective One-Year Case Series

Abstract

Objectives: We sought to evaluate CBCT-based dimensional outcomes, short-term dimensional changes, the feasibility of delayed implant placement, and complication profiles after defect-adapted guided bone regeneration of the atrophic edentulous maxilla using a PRGF-enriched autogenous bone/anorganic bovine bone mineral composite, including cases requiring simultaneous lateral-window sinus floor elevation. Materials and Methods: In this prospective, single-arm, non-randomized clinical case series, 11 patients with an atrophic edentulous maxilla requiring prosthetically guided reconstruction before implant placement were consecutively treated. Eligibility criteria included a residual ridge width < 6 mm and/or residual bone height < 10 mm, with ASA I–II status. Patients underwent defect-adapted GBR with a 60:40 mixture of autogenous bone and anorganic bovine bone mineral combined with plasma rich in growth factors (PRGF), stabilized within a defect-adapted barrier membrane system. Eight patients received combined vertical and horizontal augmentation, and three received horizontal augmentation, with simultaneous sinus floor elevation performed where anatomically indicated. Implants were placed in a delayed protocol at re-entry (6–9 months). Bone height and width were measured using standardized cone-beam computed tomography at baseline, immediately post-operatively, at 6–9 months, and at 12 months at three maxillary reference sites. Selected bone core biopsies obtained at re-entry were processed for descriptive histological evaluation. Results: Mean vertical bone dimension increased from 6.8 mm pre-surgically to 14.9 mm immediately postoperatively and measured 14.5 mm at 6–9 months and 13.9 mm at 12 months; mean horizontal bone dimension increased from 4.1 to 8.8 mm and measured 8.6 and 8.2 mm, respectively, at the corresponding follow-up time points. At 12 months, the retained mean dimensional gain was 7.1 mm vertically and 4.1 mm horizontally. Descriptive histological evaluation of selected bone core biopsies showed newly formed bone associated with residual bone-substitute particles and bone–biomaterial interface remodeling. In total, 75 implants were placed according to a delayed protocol. No intra-operative complications occurred. Three low-grade infections resolved without loss of the regenerative construct, whereas one high-grade infection caused complete graft loss at the affected site; it was excluded from the bone-gain analysis. Conclusions: Within its limitations, the PRGF-enriched autogenous bone/ABBM composite stabilized within a defect-adapted GBR compartment was associated with substantial vertical and horizontal augmentation of the severely atrophic edentulous maxilla, with limited mean linear dimensional reduction between the immediate postoperative and 12-month assessments. The approach enabled delayed implant placement in prosthetically guided positions. Controlled studies with longer follow-up are required to clarify the contribution of PRGF and validate the long-term functional performance of this multi-component regenerative biomaterial strategy.