Synergistic cytotoxic effects of ions released by zinc-aluminum bronze and the metallic salts on osteoblastic cells.

GRILLO, C; MORALES M.L.; MIRIFICO, M.V.; FERNÁNDEZ LORENZO DE MELE, M

JOURNAL OF BIOMEDICAL MATERIALS RESEARCH PART A

WILEY-LISS, DIV JOHN WILEY & SONS INC

Lugar: New York; Año: 2013 vol. 101 p. 2029 - 2040

1549-3296

The use of copper based alloys for fixed dental crowns and bridges is increasingly widespread in several countries. The aim of this work is to study the dissolution of a zinc- aluminum bronze and the cytotoxic effects of the ions released on UMR-106 osteoblastic cell line. Two sources of ions were employed: i) ions released by the metal alloy immersed in the cell culture and ii) salts of the metal ions. Conventional electrochemical techniques, atomic absorption spectroscopy (to obtain the average concentration of ions (AC) in solution) and energy dispersive X ray spectroscopy (EDX) analysis were employed to study the corrosion process. Corrosion tests revealed a strong influence of the composition of the electrolyte medium and the immersion time on the electrochemical response. The cytotoxicity was evaluated with a) individual ions; b) combinations of two ions, c) the mixture of all the ions released by a metal disc of the alloy. Importantly, synergistic cytotoxic effects were found when Al-Zn ion combinations were employed at concentration levels lower than the cytotoxic threshold values of the individual ions. Cytotoxic effects in cells in the vicinity of the metal disc were also found. These results were interpreted considering synergistic effects and a diffusion controlled mechanism that yields to concentration levels, in the metal surroundings, several times higher than the measured AC value.