FAILURE OF ETHYLENE-OXIDE TO STERILIZE EXTRACTED HUMAN TEETH

Objectives. The purpose of this study was to determine ii ethylene oxi de could sterilize extracted human teeth to be used in research. Metho ds. An occlusal preparation was cut in freshly extracted molars, and a small hole was drilled into the pulp chamber. A suspension of Bacillu s subtilis (globigii) endospores, the standard biological monitor used for ethylene oxide sterilization, was injected into the pulp cavity, and the pulp cavity access was filled with composite material and seal ed with a light-cured sealant. The teeth were exposed to either a 30 d egrees C or 63 degrees C ethylene oxide sterilization process. Followi ng exposure, the teeth were aseptically split and cultured to reveal v iable spores. Results. Sixty-four percent of the teeth exposed to ''co ld'' ethylene oxide treatment and 80% of the teeth exposed to the ''wa rm'' treatment still contained viable spores. Significance. Ethylene o xide cannot be relied on to sterilize extracted human teeth. Therefore , before they are used in research, other methods should be used to en sure killing of bloodborne pathogens that may be present within the te eth.