Sol‐gel preparation and in vitro test of fluorapatite/hydroxyapatite films

Fluorapatite/hydroxyapatite (FA/HA) films have been demonstrated to be a good alternative to pure hydroxyapatite (HA) ones in medical applications because of their bioactivity and relatively low solubility. In this study, Ca(NO 3 ) 2 , P 2 O 5 , and HPF 6 were used to prepare FA/HA films on Ti6Al4V substrate with the use of a sol‐gel method. The F contents in the films could be tailored by adjusting the amount of HPF 6 added. The in vitro evaluation of the films was carried out in both SBF9# solution and TRIS buffer solution. The films with appropriate F contents showed a better ability to induce calcium phosphate deposition on their surfaces than either pure HA film and FA/HA films with even higher F content, as well as smaller dissolution amounts than HA film in TRIS buffer solution. Hence, the FA/HA films obtained in this work integrate both good bioactivity and stability, and could be a better choice for bioactive film on titanium alloys to produce high‐quality implants. © 2003 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 69B: 33–37, 2004