Evaluation of human osteoblast metabolic activity in modified titanium-conditioned medium

To evaluate human osteoblast metabolic activity cultured in medium conditioned with commercially pure titanium after surface treatments with alumina or ceramic grit-blasting followed by acid etching. Commercially available, pure Grade 4 titanium disks were used and subjected to seven different surface modifications: (1) machined (MA)-used as the control group; (2) blasted with Al₂O₃ (Al₂O₃); (3) blasted with sintered ceramic (HAS); (4) blasted with non-sintered ceramics (HA); (5) blasted with Al₂O₃ and etched with HCl/H₂SO₄ (Al₂O₃ DE); (6) blasted with sintered ceramic and etched with HCl/H₂SO₄ (HAS DE), and (7) blasted with non-sintered ceramic and etched with HCl/H₂SO₄ (HA DE). A samples roughness evaluation test was carried out with an interference microscope, and energy-dispersive X-ray spectroscopy was performed to evaluate the presence of aluminum, phosphorus, and calcium deposited during the titanium surface treatment along with carbon contaminants acquired by the surface during processing. A culture medium conditioned with the respective samples was prepared in five dilutions, and its effect on human osteoblast cell viability was evaluated using the relative viability of cells. Human osteoblast metabolic activity was found to be the most intensive for the Al₂O₃ DE sample. The lowest activity was observed for the HAS DE. The material's cytocompatibility depended on both the surface roughness and its chemical composition. Etching had a dual effect on cell activity, depending on the chemical composition of the titanium surface after blasting.