3D-printable bioactive glass-based polymer-infiltrated ceramic for biomimetic tooth root applications

Titanium implants are widely utilized for tooth root reconstruction due to their excellent mechanical and biological properties. However, their mechanical properties differ from those of dentin. This study aims to develop a 3D-printable polymer-infiltrated ceramic network (PICN) as a tooth root restoration material that mimics the natural root shape, mechanical properties, and biocompatibility. A bioactive glass (BG)-based photocurable slurry was prepared for vat photopolymerization, printed, sintered, and subsequently polymer-infiltrated to form 3D-printable PICN (3D-PICN). For comparison, 3D-printable BG (3D-BG), a dense ceramic without resin infiltration, was fabricated using the same printing and sintering process. The photocurable slurry was characterized for its rheological and photopolymerization behaviors, including viscosity, cure depth, degree of conversion, overgrowth, and printing accuracy. The results confirmed its suitability for vat photopolymerization, enabling the precise fabrication of tooth root-shaped structures. Mechanical properties, including work of fracture, flexural strength, flexural modulus, and Vickers hardness, were evaluated for both 3D-PICN and 3D-BG. The results revealed that the mechanical properties of 3D-PICN closely match those of dentin, whereas 3D-BG exhibits properties similar to enamel. Biocompatibility was assessed through in vitro simulated body fluid immersion tests and in vivo implantation in a ten-week-old rat tibia model, followed by histological analysis. The findings confirmed good biocompatibility of 3D-PICN with bone tissue. The 3D-PICN demonstrated excellent printability, mechanical compatibility with dentin, and favorable biocompatibility, suggesting its potential as a promising material for tooth root reconstruction applications.