Harnessing and Optimizing α-TCP for Oral Tissue Engineering and Regenerative Dentistry.

α-Tricalcium phosphate (α-TCP), a resorbable calcium phosphate bioceramic, has emerged as a promising biomaterial for oral tissue regeneration due to its exceptional osteoconductive properties and compositional similarity to natural bone. During hydrolysis, α-TCP releases calcium (Ca²⁺) and phosphate (PO₄³⁻) ions that actively promote tissue mineralization, making it particularly valuable for applications in periodontal bone repair, periapical lesion treatment, and dental hard tissue remineralization. However, while α-TCP demonstrates excellent initial osteogenic activity, its rapid degradation kinetics in physiological environments often lead to premature structural collapse, localized hyperphosphatemia, and inconsistent bone formation outcomes. This review examines the current applications of α-TCP in oral medicine, with particular focus on its clinical use in apexification, alveolar ridge preservation, and guided bone regeneration. We critically analyse the material's limitations, including its mechanical instability in load-bearing sites and unpredictable resorption profiles that may hinder long-term regenerative outcomes. Emerging strategies to overcome these challenges are discussed, such as the development of composite systems combining α-TCP with β-TCP, hydroxyapatite, or biodegradable polymers to achieve optimized degradation rates and enhanced mechanical performance. Furthermore, we explore innovative approaches in material design, including surface functionalization with bioactive molecules and the fabrication of three-dimensional printed (3D-printed) α-TCP scaffolds with controlled porosity. The review concludes by identifying key research directions for the field, emphasizing the need for improved in vivo degradation models, standardized clinical evaluation protocols, and the development of smart α-TCP composites capable of spatiotemporal control over ion release. By addressing these challenges, α-TCP-based materials may realize their full potential as next-generation solutions for oral tissue engineering and regenerative dentistry. Furthermore, this review uniquely synthesizes the literature by grouping findings according to key performance outcomes - including mechanical strength, degradation kinetics, and osteogenic efficacy - to provide a clear, comparative analysis of how different material design strategies directly influence biological and functional results.