Invitro evaluation of cytotoxicity and elemental release of three types of Nickel - Chromium basemetal alloys and comparison with one type of high noble (Gold-Palladium- Silver) alloy

Dental alloys following corrosion cause changes in oral tissues. As base metal alloys are used for fabrication of dental prostheses and are manufactured in Iran, the aim of this study was to investigate the cytotoxicity of three types of nickel – chromium base metal alloys with one type of high noble alloy on mouse fibroblast cell (L 929) by MTT test. Methods & Materials: In this experimental study, 12 disks of each alloy with 5mm diameter and 2.5 mm thickness were prepared and placed in RPMI culture medium for 48 hours & 72 hours (extract medium). Then the extract mediums were diluted in two different dilutions of 200 μl & 40 μl and their cytotoxicity were evaluated by MTT assay and compared with two control groups consist of only culture media & culture media with teflon. The amount of Nickel, chromium, copper, zinc & silver released from each alloys were measured by flame atomic absorption device. The data were analyzed by Graph Instat software, one way ANOVA and Tukey tests. After 48 hours, no significant difference in cytotoxicity was found between samples and control groups. After 72 hours there was a significant difference between samples and control groups (Minalux vs. Control: P<0.01, Degubond vs. Control: P<0.001, Wiron 99 vs. Control: P<0.001, Supercast vs. Control: P<0.05). There was no significant difference in cytotoxicity with two dilutions of 200 μl & 40 μl between samples. Maximum release of nickel and chromium were observed from Minalux, silver from Degubond and zinc from Supercast. The cytotoxicity of three Nickel-Chromium alloys and one high noble which were used in this study was not different. Cytotoxicity increased with time.