A Study on the Evaluation of the Cytotoxicity of Al_2O_3, Nb_2O_5, Ta_2O_5, TiO_2 and ZrO_2


Abstract: Nearly all metals used in implants are pure or alloys composed of transition elements forming spontaneously passive layers on the surface in electrolytes in a wide pH region. The biocompatibility of these metals used in implants is tested before surgical implantation. Determining the biocompatibility of these metals is implemented firstly by the testing of their cytotoxicity. The first step consists of evaluating the cell morphology and proliferation. In this study, glass slices were coated with Al_2O_3, Nb_2O_5, Ta_2O_5, TiO_2 and ZrO_2 using the sol-gel technique. Then Vero fibroblast cells were inoculated with these slices and the influence of metal oxides on cell proliferation and morphology was observed. Metal oxides did not affect the cell morphology. However, the cell counts varied compared to those of the uncoated glass slices (control): cell numbers decreased 30% with Al_2O_3 and Nb_2O_5, by 45% with Ta_2O_5 and by 58% with ZrO_2. There was no change in cell numbers with TiO_2. These results might give an idea about the cytotoxicity of the metal oxides tested. However, the application of other cytotoxicity tests and the testing of the samples with several other cell types seem to be necessary.

Keywords: Cytotoxicity, Cell morphology, Oxide layer, Sol-gel coating, Glass

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