Comparison between Sulphorhodamine-B dye staining and⁵¹Cr-release method in cytotoxicity assay of endodontic sealers

Abstract

The aim of this study was to evaluate Sulphorhodamine-B (SRB) staining against51Cr-release in cytotoxicity tests of six endodontic sealers, namely, MU sealer (Mahidol University) ROCANAL 2, ROCANAL 3, Apexit, Endomethasone, and AH26. Monolayers (5 x 105cells/ml) of the mouse cell line Mu-mu-1 were used as test cells. Following incubation at 37°C in 5% CO2for 24 h in the presence of each sealer, cells were stained with 0.4% SRB and the absorbance at 540 nm determined as measure of cell viability. For51Cr-release assay, cells were labelled with51Cr before testing with sealers, and radioactivity in the supernatant was measured in a liquid scintillation counter. Both techniques indicated that Apexit was the least toxic sealer. In view of the ease of conducting SRB staining for tests of cell viability, this may be the method of choice over51Cr-release assay in the evaluation of endodontic sealer cytotoxicity. Copyright © 1997 by The American Association of Endodontists.