Clinical and Biomimetic Strategies for Dental Implantation in Insufficient Bone Volume Conditions

Dental implants are surgically placed medical devices that restore masticatory function and improve esthetics by providing a stable foundation for prosthetic restorations like crowns, bridges, and dentures. The long-term success of implants depends on sufficient alveolar bone volume and quality. When patients present with alveolar bone defects, achieving optimal bone volume is critical for successful implantation. Bone grafts, including autologous, allogeneic, xenogeneic, and synthetic substitutes, are commonly used for bone reconstruction. However, these grafts have limitations, such as limited availability, donor site morbidity, disease transmission risks, and reduced osteoinductive properties. Our research focuses on synthetic bone substitutes combined with recombinant human bone morphogenetic protein-2 (rhBMP-2), a key osteogenesis regulator. We developed a novel rhBMP-2 delivery system (rhBMP-2/BioCaP) that incorporates a low dose of rhBMP-2 within a biomimetic calcium phosphate coating, enabling localized, controlled release for bone regeneration. Bone augmentation is a primary technique in implantology for treating alveolar bone defects. In severe cases, traditional augmentation methods may not be sufficient. Alternative implant placements, such as zygomatic and pterygoid implants, can provide structural support in areas with adequate bone volume. These approaches help restore both function and esthetics in patients with significant bone loss. In our study, we reviewed calcium phosphate ceramics and bioactive agents for osteogenesis in implant dentistry and assessed the efficacy of rhBMP-2/BioCaP-based materials in bone regeneration. Clinical trials investigated rhBMP-2/BioCaP/β-TCP as a socket preservation graft, while animal experiments evaluated rhBMP-2/BioCaP/CPC for lateral bone augmentation. Chapter 2 discusses artificial calcium phosphate biomaterials and their role in bone defect repair. Implant-supported prostheses require sufficient peri-implant bone for stability. Alveolar bone defects, often caused by extractions, metabolic disorders, or trauma, necessitate augmentation for successful implant placement. Calcium phosphates, known for their biocompatibility and osteoconductivity, are commonly used in combination with growth factors to enhance bone regeneration. Chapter 3 demonstrates that rhBMP-2/BioCaP/β-TCP significantly increases new bone volume density compared to β-TCP alone. Patients in this group required fewer bone augmentation procedures during implant placement. However, long-term studies are needed to validate these findings. Chapter 4 explores radiographic and histomorphometric assessments of rhBMP-2/BioCaP/β-TCP. Cone-beam computed tomography (CBCT) showed greater volume gain in treated patients, while histological analysis confirmed faster material degradation, aligning with radiographic results. This highlights CBCT as a valuable tool for evaluating bone graft resorption. Chapter 5 examines horizontal bone augmentation using rhBMP-2/BioCaP/CPC in animal models. The results show improved bone volume and marrow formation compared to CPC alone, demonstrating the enhanced regenerative potential of rhBMP-2/BioCaP/CPC for clinical applications. Chapter 6 investigates virtual pterygoid implants for maxillary atrophy treatment. Software simulations of 116 virtual implants at the pterygoid-maxillary junction determined optimal implant positioning based on anatomical variations and sinus volume. Findings showed that 90% of planned implants maintained close proximity to the sinus cavity, confirming their potential for stable anchorage in maxillary atrophy cases.