Evaluation of cytotoxicity and up-regulation of gelatinases in human fibroblast cells by four root canal sealers

Silva EJNL, Accorsi-Mendonc, a T, Almeida JFA, Ferraz CCR, Gomes BPFA, Zaia AA. Evaluation of cytotoxicity and up-regulation of gelatinases in human fibroblast cells by four root canal sealers. International Endodontic Journal, 45, 49-56, 2012. Aim To investigate the effects of root canal sealers on the cytotoxicity and gelatinolytic activity of matrix metalloproteinases (MMPs) in human fibroblasts. Methodology Human fibroblasts (MRC5, 3 x 105 cells per well) were incubated directly or indirectly with AH Plus, Endomethasone N, Pulp Canal Sealer EWT or Sealapex for 30 min, 1, 4 or 24 h (time-points). The cytotoxicity of all root canal sealers was determined by counting viable cells using the trypan blue exclusion assay. Supernatants of cell cultures incubated with root sealers directly or indirectly were collected after each time-point to determine the levels of MMP-2 and MMP-9 gelatinolytic activity by gelatin zymography. Data were analysed using anova and the Tukeys tests. Results Cells secreted MMP-2 after periods of 4 and 24 h; however, there were no significant differences between the sealers. Secretion of gelatinases was elevated by root canal sealers in direct contact with the cell monolayer when compared to indirect contact (P < 0.05). At the time-points tested, no gelatinolytic activity could be detected in the control group without the sealers. The cytotoxicity results revealed that all sealers were cytotoxic in both contact forms. Sealapex had the lowest cytotoxicity and AH Plus the most cytotoxicity. Conclusions All root canal sealers induced the expression of MMP-2 in MRC5 fibroblasts. AH Plus had the highest cytotoxicity amongst the tested sealers, but all were associated with cytotoxic effects.