Autoclave performance in private dental practices in Hong Kong

Abstract

Objectives. In dental offices, sterilization of instruments is one of the most important aspects of infection control. Autoclave effectiveness in killing microorganisms can be verified by spore tests. The purpose of this study was to investigate the sterilization procedures of private dental offices in Hong Kong, and to test the effectiveness of their autoclaves using biological indicators. Methods. Packages of an 18-item questionnaire and two biological indicators were sent to 402 private dental practices in Hong Kong. They were instructed to complete the questionnaire, and perform a spore test in their autoclave using the biological indicators and return them for incubation. Results. One hundred and eighty-two practices responded, with a response rate of 45%. Excluding three imcomplete questionnaires and four practices using dry heat oven, a total of 175 autoclaves were tested. Thirteen (7%) of the autoclaves failed the initial spore test. Twelve of these practices performed a re-test, whereupon two (1%) of the autoclaves failed again. Among these 175 autoclaves, 77 (44%) were the Fuji Elite model. The commonest (n=72; 41%) packing material and method entailed sterilization pouches. Twenty-three (13%) of the respondents used improper sterilization time/temperature conditions for processing the instruments. For autoclaves older than 1 year, only 38% (n=58) had been serviced in the last year. One hundred and nine (62%) of the respondents used chemical indicators and only seven (4%) used biological indicators to monitor sterilization. Conclusion. Autoclaves in private dental practice in Hong Kong should be regularly checked, and their effectiveness routinely monitored. The use of biological indicators to monitor the sterilization was uncommon and knowledge about proper autoclaves usage needs improving.