Evaluation of cytotoxicity of five different one-step self etching adhesives in cell culture medium

Adhesive resins used in dentistry must strongly bond the restorations to the dental tissue and should not be toxic for vital tissues. In-vitro cytotoxicity tests in which cells directly contacted with material are usually used in determining cytotoxic effect of self-etch adhesive systems that are increasingly used in clinics today. By these methods; the changes caused on the cell vitality, morphology, membrane integrity and metabolic activity have been evaluated. The purpose of this study is to make comparision of potential for cytotoxicity of five different one-step self-etching adhesives [Prime&Bond One Select (PB-OS), Optibond All-in-One (OB-AIO), G-bond (GB), Clearfil Universal Bond (CUB), Single Bond Universal (SBU)] that are widely used in dentistry with direct contact method as qualitative and quantitative in the cell culture medium. In the first phase of our research; the adhesive materials were applied on monkey's kidney epithelial cell line [CCL81 (Vero)] with direct contact method. Cytotoxicity was assessed qualitatively by defining the reaction zones formed in the culture medium with changes in the density and morphology of the cells. As a result; in the SBU, CUB, GB, and OB-AIO groups, zone formation exceeding 1cm around and under the test material was identified. In the PB-OS group, zone formation borders were found about to 1 cm. In the second phase; four different dilutions (1%, 0.1%, 0.01% and 0.001%) of the test materials were added to the L929 mouse fibroblast cell culture medium. The effects on cell proliferation of the test materials which was incubated in three different time periods (24, 48 and 72 hours) was assessed by MTT assay. In the statistical analysis of obtained results; it was found that after 24 hours period CUB, after 48 hours period GB and SBU, after 72 hours period OB-AIO were the most cytotoxic materials. It was observed that the cytotoxic effect of all adhesives significantly increased depending on dose and showed variety depending on time.