Assessment of the effectiveness of dental sterilizers using biological monitors.

This study was undertaken to evaluate the effectiveness of steam, chemical vapor, and dry heat sterilizers, over a three-year period, in dental operatories subscribing to the University of British Columbia's sterilization monitoring service. A total of 4,579 sterilizer loads were tested. The results demonstrated an overall failure rate of 4.4 per cent. Individual failure rates for each type of sterilizer were: chemiclaves, 4.9 per cent; steam autoclaves, 2.3 per cent; and dry heat ovens, 7.9 per cent. In 38 per cent of these cases, the reasons for failure could be attributed to a definite cause.