SLA-3D printing and bioactivity enhancement of zirconia anchor screws for temporomandibular joint disc reduction surgery

A method is proposed for 3D printing and enhancing the surface bioactivity of zirconia ceramic anchor screws, specifically tailored for temporomandibular joint disc reduction surgery. Initially, the challenge posed by the brittleness and processing difficulties of fine ceramic anchor screws was addressed through the application of SLA-3D printing technology. This allowed for an exploration of the forming accuracy and biomechanical properties of the printed anchor screws. According to research findings, the dimensional deviation in the thread processing of 3D printed zirconia screws is approximately 100 μm. When the threaded segment measures 7.0 mm in length, the 3D printed zirconia anchor screw, with a diameter of 2.7 mm, demonstrates comparable maximum axial tensile forces 102.91 N to a titanium screw of 2.0 mm diameter. The maximum vertical tensile force of the zirconia anchor screws exceeds the breaking force of the anchor suture by 21.03 N, fulfilling the requirements for clinical application. Additionally, the application of a ZrO₂-PDA-La³⁺ composite biological coating enhances the surface bioactivity of the 3D printed zirconia anchor screws. PDA ensures reliable adhesion of the biological coating during the implantation process, while La³⁺ significantly boosts the osteogenic capacity of the zirconia ceramic surface, thereby contributing to the long-term stability of the implant. Ultimately, zirconia anchor screws satisfying basic clinical requirements in terms of mechanical properties and biological activity were successfully developed, offering a novel treatment option for ADDwoR patients, particularly those with metal allergies.