In Vitro Cytotoxicity of a New Epoxy Resin Root Canal Sealer

Abstract

The cytotoxic effects of a new epoxy resin-based root canal sealer (AH-plus), together with those of two other commonly used endodontic sealers (AH26 and zinc oxide-eugenol), have been studied in vitro on a culture of human gingival fibroblasts. Cytotoxicity was assessed by direct incubation of sealers' extracts with the cultured fibroblasts at different time intervals. Morphological and cytotoxic effects of the sealers were evaluated microscopically and spectrophotometrically using the neutral red cytotoxicity assay. Our results demonstrated that the cytotoxic effects induced by zinc oxide-eugenol were detectable as early as 1 hr after mixing and remained at a high level until completion of the experiment (5 wk). AH26, however, induced early cytotoxic effects that lasted for 1 wk, followed by a substantial reduction in cytotoxicity. Cytotoxicity of the AH-plus was confined to the early period of experiment and was no longer detectable after 4 hr of mixing. Comparison between the results obtained for each sealer revealed significant differences at particular time intervals. Our findings suggest the potential advantage of this sealer over the other two sealers.

Evaluation of the cytotoxicity of calcium phosphate root canal sealers

“…AH Plus, a new formulation of the epoxy resinbased sealer AH26, exhibited severe cytotoxicity immediately after mixing, but its cytotoxicity sharply decreased after 8h. These results were in accordance with the study by Azar et al 17) . Leyhausen et al 23) reported that AH Plus caused minor or no cytotoxic effect and no genotoxic effect with 24h set sealer.…”

“…The cause of this long-lasting cytotoxicity may be related to unreactive eugenol or zinc ion remaining in the zinc oxide and eugenol mixture [16][17][18] . Similar results were obtained in the studies of ZOE by Others 17,18) . Sealapex also showed severe long-lasting cytotoxicity until the end of the observation periods after it initially showed moderate cytotoxicity.…”

“…Leyhausen et al 23) reported that AH Plus caused minor or no cytotoxic effect and no genotoxic effect with 24h set sealer. Short time cytotoxicity of AH Plus could probably be due to its low contents of water-soluble toxic substances (presumably formaldehyde and epoxy derivatives of bisphenol-A-diglycidylether) and short setting time (8h) 17) . Ketac Endo, glass ionomer based-sealer, induced high cytotoxic effect at the early stage like the AH Plus, but it showed slight cytotoxicity after 24h.…”

Effect of time of extraction on the biocompatibility of endodontic sealers with primary human fibroblasts

“…8,18,24,25 Also, in accordance with Miletic et al 25 and Al-Hiyasat et al, 26 cytotoxicity was reduced after 7 days, while the present work also showed a decrease by 14, 21, and 28 days. In contrast, Azar et al, 27 using the neutral red assay, demonstrated that AH Plus induced significant cytotoxicity at 1 and 4 h, but no toxicity was detectable after 4 h. Huang et al 28 demonstrated that AH Plus at 24 h was cytotoxic to astrocytes in a dose-dependent manner. They showed that this sealer was also genotoxic, with an inhibitory dose (ID 50 ) of 0.04 mg/mL.…”

Evaluation of the radiopacity and cytotoxicity of resinous root canal sealers

“…Epoxy resin-based sealers have been introduced in endodontic practice because of their favorable characteristics, such as adhesion to tooth structure, long working time, easey manipulation, and good sealing ability 14) . Several studies showed that polymerized resin-based sealers presented less cytotoxicity compared to zinc oxide-eugenol and calcium hydroxide-based sealers 15,16) . However, the cytotoxic effects of resinbased root canal sealers related to their radiopacity have not yet been studied.…”