Contamination of gutta-percha and Resilon cones taken directly from the manufacturer

Any substance and material placed in the root canal either temporarily or definitively must be free of microbial contamination. The purpose of the present study was to evaluate the percentage of contamination of Resilon cones, a polycaprolactone-based material, and seven different brands of gutta-percha cones available in the specialized market. Cones were removed from their original manufacturer boxes and immediately transferred to tubes containing thioglycolate broth. Tests were carried out in triplicate. In addition, for quantitative analysis of possible contaminants, cones were taken from their packages, transferred to tubes containing saline solution, agitated, and aliquots of this solution were seeded onto Mueller-Hinton agar plates. No sample showed contamination in any of the tests performed. Despite the absence of detectable contamination before the first use, a rationale for routinely disinfecting cones before placing them into root canals is given.