ABSTRACT
In many cases of endodontic treatment like retrograde surgery and perforation correction, because the materials are placed adjacent to vital connective tissue, biocompatibility and non cytotoxicity are of great importance and improve healing process. Among so many introduced materials, amalgam has been used for many years as a low cytotoxic material. Mineral Trioxide Aggregate [MTA] has been introduced as a new material with high biocompatibility and cementogenesis stimulation. The purpose of this study was the comparison of the cytotoxicity of amalgam and MTA on L[929] cell culture using light microscope. Different dilutions of fresh and set materials were placed adjacent to flasks of L[929] in DMEM media for 24h, 48h, 72h and 4 and 6 days. Then qualitative evaluation of cell morphology by light microscope were done. In qualitative evaluation on L[929] cells with light microscope, fresh-neat amalgam had a moderate cytotoxic effect as proliferation inhibition, whereas fresh MTA had a low cytotoxic effect. Set materials had no cytotoxic effects. According to our findings, MTA revealed a lower degree of cytotoxicity than amalgam. Thus MTA could be used nearby the vital connective tissue