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.
(© 2012 Blackwell Publishing Asia Pty Ltd.)