Cytotoxicity and subcutaneous tissue response of beta RCS in comparison with ADSeal and AH plus endodontic sealers: in vitro/in vivo study

Sealers are an important part of root canal obturation. Therefore, these materials must be biocompatible and non-toxic to the cells. This study compared the cytotoxicity and tissue response of Beta RCS, ADSeal, and AH Plus. In the in vitro phase, the cytotoxicity of Beta RCS, ADSeal, and AH Plus for human gingival fibroblasts (HGFs) was evaluated using the methyl thiazolyl tetrazolium (MTT) assay after 1, 3, and 7 days (non-toxic defined as > 90% viability). In the in vivo phase, polyethylene tubes containing the sealers (n = 54) and empty control tubes (n = 18) were implanted subcutaneously in 18 Sprague-Dawley rats (4 tubes per rat). The rats were sacrificed after 7, 21 and 42 days. Histological sections were then evaluated under an optical microscope for inflammation, vascular reaction, and fibrous tissue formation. Data were analyzed using the Kruskal-Wallis and Mann-Whitney tests (alpha = 0.05). The cytotoxicity of all three sealers significantly increased with time (P < 0.05). At days 3 and 7, the cytotoxicity of AH Plus was significantly higher than other sealers (P < 0.001). Beta RCS and ADSeal had no significant difference regarding cytotoxicity. At day 21, AH Plus showed significantly higher inflammation and fibrous tissue formation than the control group (P < 0.05). At day 21, tissue reaction around Beta RCS and AH Plus was significantly greater than around ADSeal (P < 0.05). AH Plus showed the highest cytotoxicity while Beta RCS and ADSeal equally had a cytotoxicity comparable to the control group. Both Beta RCS and AH Plus showed high tissue response. ADSeal showed the lowest cytotoxicity and tissue response.