Cytotoxicity of flowable resin composite on cultured human periodontal ligament cells compared with mineral trioxide aggregate

Aim: To investigate the cytotoxicity of three flowable resin composites that potentially useful as retrograde filling materials, compared with mineral trioxide aggregate (MTA). Methods: Ten standard cylinder discs were used for each of the tested materials: Tetric Flow, Filtex Flow, Aeliteflo, and MTA, which were prepared under aseptic conditions. Cytotoxicity of eluates from all materials after 1–4 days’ immersion in culture medium and direct contact cytotoxicity were evaluated using cultured human periodontal ligament cells (PDLC). The colorimetric (3‐[4,5‐dimethylthiazol‐2‐yl]‐2,5‐diphenyltetrazolium bromide) assay and scanning electron microscope of cell morphology (direct contact only) were used. Results: No eluates of set materials demonstrated cytotoxicity at any concentration or elution time. Freshly‐mixed MTA was cytotoxic in direct contact, but not set MTA. Freshly‐mixed Aeliteflo was also cytotoxic, as was set material up to 2 days’ elution. With morphological assessment, some differences were seen among resin composites, but all changes were rated as slight using the International Standard Organization criteria. Conclusions: Of all of the materials tested, Tetric Flow showed the least cytotoxic effects on PDLC. Further research is needed to determine the clinical usefulness of flowable composites as retrograde filling materials.