Rapid decontamination of gutta-percha cones with sodium hypochlorite.

Gutta-percha cones are now widely used to fill root canals. Because they cannot be sterilized by conventional autoclaving or in a hot-air oven, gutta-percha cones require rapid chairside decontamination before use to maintain the aseptic chain, an essential factor in successful endodontic therapy. The purpose of this study was to compare the effectiveness of different concentrations of sodium hypochlorite (0.25% to 4%) in sterilizing gutta-percha cones artificially contaminated with Staphylococcus aureus and Escherichia coli strains, and Bacillus subtilis spores. After 1 min of treatment, the solutions tested showed bactericidal and sporicidal effects at concentrations of 0.25% and 1%, respectively. At a concentration of 0.25%, the solutions tested were effective in destroying spores after 5 min of exposure. Based on this study, treatment of the cones for 1 min with 1% sodium hypochlorite (Milton's solution) or for 5 min with Dakin's liquid (0.5% sodium hypochlorite) is recommended.