Human Gingival Fibroblasts Response to Different Endodontic Sealers: An In Vitro Study

Endodontic treatment aims to eliminate infection of the root canals and fill the dental pulp space. The biocompatibility studies of the sealers used in root canals obturation are crucial since they are applied in direct contact with periradicular tissues. Objective: The aim of this study was to evaluate the cytotoxicity of three root canal sealers-AH Plus, Bio MTA+, and Bio C sealer-on immortalized human gingival fibroblasts. Methods: AH Plus, Bio MTA+, and Bio C sealers were evaluated through incubation in real-time and material-conditioned media. Cells were incubated for 24 h and 72 h, at three different concentrations (1, 10, and 100 mg/mL) of each sealer. The cytotoxic activity of the sealers was assessed by Methyl tetrazolium (MTT) and Sulforhodamine B (SRB) assays. Cell morphology and cytogenetic alterations were studied microscopically. Results: MTT and SRB assays revealed similar results within both approaches. Cell culture exposed to sealers through incubation in real-time revealed a cytotoxic effect of AH Plus at 100 mg/mL. Material-conditioned media study revealed a cytotoxic effect of Bio MTA+ and Bio C, increasing with higher compound concentration and reaching 50% with 100 mg/mL. Regarding the cell's morphology, Bio C sealer revealed a decrease in cell confluence and several morphological changes. AH Plus and Bio MTA+ did not seem to affect the cell confluence however morphology alterations were observed. In the cytogenetic study, a severe decrease of the mitotic index and a large number of chromosomal aberrations were observed. The present study represents an advance in the understanding of the biocompatibility of AH Plus, Bio MTA+, and Bio C sealers. These sealers demonstrated some cytotoxicity, depending on the concentration used. Although more validation studies are still needed, this study brings very relevant results in terms of cytotoxicity, cell morphology, and cytogenetic alterations. Conclusions: These results could help in the selection of the most appropriate compounds to be used in clinical practice as well as to determine the maximum recommended amounts of each sealer. Clinical Relevance: This study highlights the potential cytotoxic effects of three commonly used root canal sealers on human gingival fibroblasts, with varying degrees of impact depending on the concentration used. The results emphasize the importance of careful consideration when selecting and applying these materials in clinical practice.