Cytotoxicity of new MTA-products on L929 and human PDL cells

Objectives: Mineral trioxide aggregate (MTA) is an endodontic biomaterial which can be used in many different endodontic procedures. The aim of this in vitro study was to assess the cytotoxic effects of two existing mineral trioxide aggregate cements (ProRoot MTA-White, Dentsply-USA, and MTA Angelus-Gray, Angelus-Brazil) and compare with new MTA products (MTA Angelus Blanco, Angelus-Brazil, MTA Angelus Bio, Angelus-Brazil, DiaRoot BioAggregate, DiaDent-Canada) using a mouse fibroblast cell line (L929) and primary human periodontal ligament cells (PDL).

Methods: Standard samples of each material were fabricated in cylindrical blocks, 8.4-mm diameter and 1-mm height. After material setting in a humid chamber for 24 h at 37°C, extracts were obtained in cell culture medium for 24 h. Cells were cultured using standard procedures and were plated in 96-well culture plates at a density of 10.000 cells/well and exposed to undiluted and diluted eluates for 24 and 72 hours. Cell viability was determined by diphenyltetrazolium bromide-(MTT) assay. Analyses for determination of differences between groups were accomplished using a one-way analysis of variance with a multiple comparison test (P<0.05). Morphology of all cells was also examined.

Results: Compared to the control group, the undiluted eluates of all materials had significantly inhibited the viability of the cells after 24 h in the cultures of both L929 and PDL cells. This cytotoxic effect of the undiluted eluates was also shown after 72 h on the L929 but not on the human PDL cells. After dilution of eluates by 50 % the eluates of MTA-Angelus Gray demonstrated more cytotoxicity to L929 than the other diluted materials after both 24 and 72 h of cultures.

Conclusion: The toxicity of MTA products depended on the cell-culture system, material and dilution rate of eluate used.

Acknowledgements: Material support of Angelus and DiaDent companies and financial support of Research Council of Norway.