In Vitro Cytotoxicity and Setting Time Assessment of Calcium-Enriched Mixture Cement, Retro Mineral Trioxide Aggregate and Mineral Trioxide Aggregate.

Introduction: The present study sought to evaluate and compare biocompatibility and setting time of Retro mineral trioxide aggregate (MTA), calcium-enriched mixture (CEM) and Angelus MTA.

Methods and Materials: CEM cement, Angelus MTA and Retro MTA were assessed in set and fresh states. Extracts transformed to each cavity of three 24-well plates in which 1×104 cell were seeded into each well 24 h earlier. All specimens were incubated in a humidified incubator with 5% CO2 at 37° C. Mosmann's tetrazolium toxicity (MTT) assay was used to determine in vitro cytotoxicity on L929 mouse fibroblast cell line. Cell viability was determined at 1, 24, and 72 h after exposure. The initial setting time was measured by 113.4 g Gilmore needle testing. Then, final setting times were assessed by the 456.5 g Gilmore needle. Data comparisons were performed using the analysis of variance (ANOVA) and Tukey's post hoc test ( α =0.05).

Results: All groups in both forms indicated higher cell vitality compared to positive control group ( P <0.001). After 24 h, the set Retro MTA showed better biocompatibility compared to set CEM and set Angelus MTA ( P <0.001). Retro MTA showed significantly lower initial and final setting time compared to CEM and Angelus MTA ( P <0.001).

Conclusion: Our results indicated the good cell viability values of Retro MTA and relatively short period of setting time. It seems a promising alternative material in clinical situations where accelerated setting is required. However, more clinical and in vivo investigations are needed for a clear decision making.