CaTiO3 coating on titanium for biomaterial application -: Optimum thickness and tissue response

The objectives of this study were to determine the optimum thickness of a CaTiO3 film for biomaterial applications and to investigate the biocompatibility and bone formation of titanium with a CaTiO3 film. First, CaTiO3 films of 10, 20, 30, and 50 nm in thickness were deposited on titanium substrates using ractiofrequency magnetron sputtering followed by annealing at 873 K in air for 7.2 ks. The optimum thickness of the CaTiO3 film for bone formation was determined by comparison with its performance regarding calcium phosphate formation in Hanks' balanced saline solution (HBSS). Regarding calcium phosphate formation, the performance of the specimen with a 50-nm-thick CaTiO3 film was superior to those of specimens with other thicknesses. A titanium prism with a CaTiO3 film of 50-nm in thickness was surgically inserted in both soft and hard rat tissues. The biocompatibility of CaTiO3-deposited titanium and bone formation on it was investigated by histological observations. A slight inflammatory reaction was observed around the titanium with the 50-nm-thick CaTiO3 film, while no severe response, such as degeneration and necrosis, was observed in either soft or hard rat tissue. New bone formation on the titanium plate with the CaTiO3 film was more active than that without the film. The 50-nm-thick CaTiO3 film has biocompatibility and can facilitate new bone formation in vivo, and, consequently, it is an excellent surface modification method for biornaterial applications. (c) 2007 Wiley Periodicals, Inc. J Biomed Mater Res 82A: 304-315, 2007