Effects of hydrothermal treatment with CaCl₂ solution on surface property and cell response of titanium implants

In order to obtain early and good osteointegration after implantation of a titanium implant in the human body, the surface modified treatments using NaOH or H₂O₂ etc. were reported. In this study, titanium was hydrothermally treated with CaCl₂ solutions at 200°C for 24hr (CaCl₂-HT). Scanning electron microscope (SEM) observation clearly showed apatite deposition on the surface of CaCl₂ HT treated titanium faster than other chemical treated titanium immersion in simulated body fluid. X-ray photoelectron spectroscopy (XPS) analysis demonstrated that Ti-O-Ca bonding was formed on titanium surface by hydrothermal treatment with CaCl ₂ solution. And it was revealed that thickness of TiO₂, which was known to play important roles for the formation of bone-like apatite, became approximately three times thicker than as-polished titanium. The amount of initial attached MC3T3-E1 cells on as-polished and NaOH, H₂O ₂ and this CaCl₂ HT treated titanium were almost the same values. After 5 days incubation, the growth rate of MC3T3-E1 cells on CaCl ₂-HT treated titanium was significantly higher than that on other chemical treated titanium. The hydrothermal treatment with 10-20 mmol/L CaCl₂ solution at 200°C was an effective method for the fabrication of titanium implant with good bioactivity and osteoconductivity.