In-vitro characterization and evaluation of innovative surface modifications of zirconia implants for the optimization of hard and soft tissue management

Purpose This study focuses on the characterization and evaluation of innovative surface modifications of zirconia implants aimed at optimizing hard and soft tissue management. Methods The cytocompatibility of newly developed ceramic implant coatings was assessed. Five different surface types were investigated: uncoated zirconia (Zr), zirconia coated with pure titanium (ZrTi), zirconia coated with calcium phosphate (CaP), zirconia coated with hydroxyapatite (HA) and zirconia coated with calcium phosphate-hydroxyapatite (CaP/HA). Cytocompatibility was assessed using L929 mouse fibroblasts and MC3T3 pre-osteoblasts. Testing was performed in both direct and indirect cell contact with the materials. In the direct contact setup, cells were cultured for 24 h on the test surfaces, followed by live/dead staining and fluorescence microscopy. In the indirect setup, material extracts were prepared and cell viability was quantified after 72 h using lactate dehydrogenase (LDH) and cell proliferation (XTT) assays. Results All tested surfaces demonstrated good cytocompatibility without significant cytotoxic effects. Supplementary scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS) analyses confirmed the successful application of the coatings and provided detailed insight into surface topography and elemental composition. Conclusion Calcium phosphate and hydroxyapatite-coated zirconia implants represent a promising biocompatible alternative to titanium-based surfaces, with the potential to improve tissue integration and long-term clinical outcomes in ceramic dental implantology.