Lateral Ridge Augmentation Using Low-dosage Bone Morphogenetic Protein-2 Functionalised Calcium Phosphate Cement

AIMS: To evaluate bone regeneration and osseointegration using low-dosage Escherichia coli-derived recombinant human bone morphogenetic protein-2 (ErhBMP-2) incorporated with calcium phosphate cement (CPC) via a biomimetic coating method during simultaneous lateral ridge augmentation with implant placement. MATERIALS AND METHODS: Chronic horizontal alveolar bone defects were created in the mandibles of 5 dogs. Before implant placement, defects were randomly assigned to different grafting groups: autologous bone, CPC, high-dosage ErhBMP-2 (1088 µg/g) adsorbed to CPC (ErhBMP-2 Ads. CPC), and low-dosage ErhBMP-2 (239 µg/g) incorporated with CPC (ErhBMP-2 Inc. CPC). Lateral ridge augmentation was performed at the buccal aspect of each defect during implant surgery. Bone regeneration and contour maintenance were assessed using micro-CT and histology 3 months postoperatively. RESULTS: Micro-CT showed that the ErhBMP-2 Inc. CPC group developed substantial mineralised tissue covering the implant surface, with no exposed threads at the implant neck. Trabecular thickness in this group was significantly greater than in the CPC and autologous bone groups. Histology confirmed greater bone marrow formation and horizontal augmentation below the implant shoulder in the ErhBMP-2 Inc. CPC group compared with CPC alone. Collectively, the histological and radiographic findings were consistent with enhanced peri-implant bone regeneration in the ErhBMP-2 Inc. CPC group. CONCLUSIONS: ErhBMP-2 Inc. CPC enhanced peri-implant bone regeneration than CPC alone. CLINICAL RELEVANCE: Low-dosage ErhBMP-2 incorporated into CPC may offer a more predictable and effective approach for simultaneous lateral ridge augmentation and implant placement by enhancing bone regeneration and maintaining ridge contours.