Digitally customized bone block allograft with enamel matrix derivative for ridge reconstruction: Case series. Histological report in humans.

Abstract

Background: Alveolar ridge resorption following tooth extraction is a common clinical challenge that can compromise esthetics, implant placement, and prosthetic rehabilitation. Digital customization of bone block allografts offers precise adaptation to the recipient site, improving graft stability and reducing surgical time. Enamel matrix derivative (EMD) has demonstrated potential to enhance osteogenic differentiation and cell adhesion; however, its application in combination with digitally customized bone block allografts (DCBBAs) remains scarcely reported. This study aimed to evaluate, bone regeneration following alveolar ridge reconstruction using a DCBBA combined with EMD through histologic and histomorphometric analysis.

Methods: Three systemically healthy, non-smoking patients with severe Seibert Class III ridge defects were treated using a DCBBA with adjunctive EMD. Grafts were digitally planned and milled based on CBCT data to achieve an ideal fit. EMD was applied to both the graft and recipient site before fixation. After 6 months of healing, re-entry surgery was performed for implant placement, during which six bone biopsies were obtained for histologic and histomorphometric evaluation.

Results: Clinically, all grafts exhibited stable integration without signs of inflammation or necrosis. Histological analysis revealed new bone formation in close contact with residual allograft particles, with viable osteocytes and osteoblasts throughout the regenerated area. Histomorphometric evaluation confirmed a predominance of mineralized bone tissue, consistent with active bone remodeling.

Conclusions: Within the limitations of this case series, the combination of DCBBAs and EMD demonstrated favorable graft integration and bone regeneration, supporting its potential as a predictable approach for reconstructing severe alveolar ridge defects.

Key points: Digitally customized bone block allografts combined with enamel matrix derivative achieved stable clinical integration without complications in severe Seibert Class III ridge defects. Histological analysis demonstrated intimate contact between newly formed vital bone and residual allograft, with viable osteocytes and active osteoblasts throughout the regenerated area. Histomorphometric evaluation showed a predominance of mineralized bone tissue after 6 months, indicating active remodeling and graft replacement by vital bone. The digitally customized workflow allowed precise graft adaptation, potentially reducing surgical time and improving biological integration in complex ridge reconstructions.

Plain language summary: Following tooth loss, the jawbone gradually loses volume, which can make dental implant treatment difficult or even impossible without prior bone reconstruction. This study evaluated a regenerative approach that combines digitally customized donor bone blocks with enamel matrix derivative (EMD), a biological protein that supports bone healing. Three patients with severe jawbone defects underwent treatment using 3D imaging and computer-guided manufacturing to produce bone grafts precisely tailored to the shape of each defect. After 6 months of healing, small bone samples were collected during implant placement and examined under the microscope. The analysis showed that the customized grafts had successfully integrated with the patients' own bone, with the formation of new living bone and active bone-forming cells, indicating ongoing tissue regeneration. These findings suggest that combining digital planning with biologically active materials may provide a predictable and accurate solution for reconstructing complex bone defects before implant therapy. By improving the fit of the graft and supporting natural bone healing, this approach has the potential to simplify treatment and enhance clinical outcomes for patients requiring extensive jawbone reconstruction.