Bio-activity of Two Cell Lines in Extracts of Portland Cements

Objective: This study aimed to compare the mitochondrial dehydrogenase activity in Human Periodontal Ligament Fibroblasts (HPLFs) and Dental Pulp Stem Cells (DPSCs) cultured in extracts of normal and fast set formulations (calcium chloride dihydrate as a setting accelerator) of white Mineral Trioxide Aggregate (WMTA, Dentsply, USA) and a locally produced white Portland cements (MAWPC, Aalborg, Malaysia). Method: The test materials at both formulations were incubated in prepared culture medium. After seven days of incubation, the extracts were prepared at five serial concentrations and applied in 96-well plates seeded with HPLFs. MTT solution was added into each well and incubated for three hours, then replaced by DMSO. The same experimental procedures were performed with DPSCs using optimized concentrations. The optical density values were measured using an ELISA reader after 24 and 72 hours. Each experiment was performed three times using three successive passages, and the mean/median cell viability values were calculated. Kruskal-Wallis and Mann-Whitney tests were performed for statistical analysis (P<0.05). Result: While all groups exhibited severe cytotoxic effects on HPLFs at maximum concentration (50 mg/ml), slight/non-cytotoxic effects were observed at <25 mg/ml. At concentration 25, MAWPC revealed a significantly higher cell viability values than WMTA at 24 hours (P<0.05). All materials behaved similarly at concentrations <12.5 mg/ml. DPSCs responded differently. In contrast to normal set formulations, severe/moderate cytotoxic effects were observed in three successive concentrations of the accelerated counterparts at both time intervals. Significant differences were identified at some concentrations of normal set formulations (P<0.05). Conclusion: MAWPC shows favourable biological response and has the potential to be used as a viable substitute to WMTA. Different cell lines may react differently with Portland cement based formulations. The addition of a setting accelerator decreased the cell viability values of MTA and PC, despite being favourable with HPLFs.