2007 Volume 20 Issue 4 Pages 592-601
Hydroxyapatite (HA) coated implants were evaluated by surface structure analyses using a surface roughness meter, an energy dispersive X-ray fluorescence spectrometer (EDX), an X-ray diffractometer and a scanning electron microscope (SEM). The seven implants used in this study were the POI implant system of Japan, AQB implant system of Japan, SPLINE implant system of USA, MAESTRO implant system of USA. PLATON implant system of Japan, TAPERED screw MP-1 of USA, and APT implant being developed in Japan. The HA coating techniques of AQB, MAESTRO, TAPERED, and SPLINE are plasma spraying, PLATON is thermal decomposition, and APT is sputtering. The roughness average (Ra) of the surface of HA coated films was in the range of 1.8-5.9 μm and the orders were AQB＞SPL＞MAE=TAP=POI＞APT＞PLA. The adhesion strength of film to substrate was largest in APT and the order of the strength was APT＞MAE＞AQB=PLA=SPL＞TAP＞POI. The thickness of the HA films was less than approximately 5 μm in PLATON and homogeneous 1-2 μm in APT. On the other hand, the thickness by the plasma spraying and the flame spraying techniques was in the range of 20 to 90 μm. The porosities of the HA films were calculated from the weight and volume of the HA films. The HA films of the APT implant were dense, while the HA films coated by plasma spraying and flame spraying techniques were porous. Significant changes in solubility and pH were not observed in each HA-coated implant.
