Aim: To investigate the cytotoxicity of five different dentine-bonding agents on human pulp cells in vitro. Methodology: Set specimens from Clearfil SE Bond (CB), Heliobond (HB), Prime & Bond NT (PB), Single Bond (SB), and Syntac Single Component (SC) were eluted with culture medium for 2 and 5 days. Cytotoxicity was judged using tetrazolium bromide reduction assay on human primary pulp cells. Results: Elutes from five dentine-bonding agents were cytotoxic to primary human pulp cells (P < 0.05). CB was the least toxic sealer amongst the chemicals tested. The cytotoxic response decreased in an order of SB > PB > SC > HB > CB. Conclusions: The influence of the cytotoxicity depended on the materials tested. Dentine-bonding agents have significant potential for pulpal toxicity.
