A comparison between gray and white mineral trioxide aggregate (MTA) and calcium enriched mixture (CEM) Cytotoxicity in L929 and Saos-2 cell lines

The purpose was to compare the cytotoxic effects of two commonly used mineral trioxide aggregate (MTA) (gray & white) with the recently introduced calcium enriched mixture (CEM) in L929 and Saos-2 cell lines and to determine the oxidative stressinduced by each cement. Sterile discs of each cement were submerged and incubated in complete media for 24, 48 and 72-h. The cell lines were exposed to two fold serial dilutions (1, 0.5, 0.25 X) of each extract. In addition to trypan blue (TB) dye exclusion test, MTT assay was carried out after 24-h. To determine the oxidative stress mediated cell toxicity, malondialdehyde (MDA) concentration and total ferric reduction activity potential (FRAP) were measured in the media.The MTT and TB results with 48-h and 72-h CEM extracts showed that both extracts are cytotoxic in L929 cell line at 1 X and 0.5 X dilutions, while neither white MTA (WMTA) nor gray MTA (GMTA) showed any toxic effects in this cell line. On the other hand all three cements (undiluted 48-h and 72-h extracts) were cytotoxic against Saos-2 cell line. The oxidative stress marker (MDA) was proportionate to the cytotoxic effects of CEM while there was no significant changes in reductive capacity of the media measured by FRAP in both cell lines.The cytotoxic effects of CEM on L929 and Saos-2 cell lines seems to be higher than WMTA and GMTA and it is increased by the time of extraction up to 72-h.. However, CEM, WMTA and GMTA showed similar toxic effect in Saos-2 cell line proportionate to the oxidative stress measured by TBARS. It seems that while all three cements extracts don't change the antioxidant activity of the media, they could significantly increase lipid peroxidation, especially CEM with Saos-2 cell line which elucidate triggering oxidative stress mechanisms without having direct oxidative activity