Evaluation of the biocompatibility of root canal sealers on human periodontal ligament cells ex vivo.

The aim of this study was to evaluate the biocompatibility of two comparatively new calcium silicate containing sealers (MTA-Fillapex and BioRoot-RCS) with that of two established sealers (AH-Plus, epoxy resin-based; Pulp-Canal-Sealer, zinc oxide eugenol containing). Human periodontal ligament cells (PDL-cells) were brought in contact with eluates from freshly mixed and set sealer. The sealers were mixed strictly according to the manufacturers' instructions and identically samples were produced. 1:1, 1:2, and 1:10 dilutions of sealers extract were used. Extracts from freshly mixed sealer were added to the PDL-cells on day one to simulate a clinical scenario. Subsequently, at 24 h, 7, 14, and 21 days extracts form set sealers were used for PDL-cell culturing. PDL-cell viability was analyzed by living-cell-count, MTT-assay, and living/dead-staining, cytotoxicity by LDH-assay, and changes by Richardson-staining. All data were statistically evaluated by one way ANOVA and a posthoc analysis with Bonferroni-Holm testing (p < 0.05). In contact with BioRoot-RCS a regeneration of the PDL-cells were observed over time. This sealer showed the lowest toxicity in a freshly mixed and set state (p < 0.05). MTA-Fillapex and Pulp-Canal-Sealer were cytotoxic in a fresh as well as in a set state, whereas AH-Plus was cytotoxic in a freshly mixed state, but not when the sealer was set. BioRoot-RCS is biocompatible and bioactive because it seems to have a positive influence on the PDL-cell metabolism. Pulp Canal Sealer and MTA-Fillapex showed no biocompatibility in contact with PDL-cells at all. Freshly mixed AH Plus is less biocompatible on PDL than in a set state.