Evaluation of the Cytotoxicity of a Newly Developed Obturating Material for Pulpectomy in Primary Teeth Using Embryonic Toxicology, Brine Shrimp Lethality, and MTT Assay: An In Vitro Study.

Objective:  The search for an ideal obturating material has taken precedence due to the revolution of the materials used in pediatric endodontics. With zinc oxide, calcium hydroxide, and metronidazole as its core constituents, an unique obturating material was developed. To aid in the healing process, the material should be biocompatible and most importantly it should not have any negative consequences. Thus, using embryonic toxicology, brine shrimp lethality, and methylthiazol tetrazolium (MTT) assay, the current investigation sought to determine the cytotoxicity of the newly developed obturating material, which contained calcium hydroxide, zinc oxide, and metronidazole at 2% 60-40 concentrations.

Materials And Methods:  In zebrafish embryonic toxicology method and brine shrimp lethality assay, five distinct concentrations of the new obturating material was tested and compared with the control in a 24-well plate containing fertilized zebrafish eggs and in 6-well plate containing nauplii, respectively. The hatching and the viability rate of the zebrafish embryos and survival rate of nauplii were calculated. In MTT assay, the percentage of fibroblast cell viability and the cell morphology was documented. A statistical analysis was performed on all of the collected data.

Results:  The hatching and the viability rate of the zebrafish embryos falls as the concentration of the new obturating material rises. The survival rate of the nauplii also falls with rise in the concentration of the obturating material. No cytotoxic effect was demonstrated by the novel obturating material on the human gingival fibroblasts up to 200 μg/mL concentration.

Conclusion:  The novel obturating material exhibits minimal cytotoxic effects even at increased concentrations.