Ethylene oxide gas has been utilized as an alternative method for sterilization of dental handpiece, as it is less corrosive than steam. However, its effectiveness for sterilization of the internal components of dental handpieces has not been established. The objective of this study was to compare the effectiveness of ethylene oxide and steam for sterilization of dental handpiece. Unused handpieces and handpieces which had been exposed to clinical dental procedures were contaminated with Streptococcus mutans, exposed to steam or ethylene oxide, and flushed with sterile saline. Washings were plated on mitis-salivarius agar, and colonies identified and counted. This data suggests that a substance entrapped within 'clinical' handpieces (possibly the biofilm) may protect bacteria from ethylene oxide gas, preventing adequate sterilization.
To understand current status of the uses of dental high speed handpiece, methods of disinfection and sterilization and their effectiveness in dental-care hospitals and out-patient departments of stomatology in general hospitals.
Ten dental-care hospitals and departments of stomatology in general hospitals at varied levels were randomly sampled during 2000 to 2001 to investigate the uses of dental autoclave and means of their disinfection and sterilization. One used dental handpiece from each hospital or department of stomatology in general hospital selected was detected for possible contamination of bacteria by aerobic bacterial count and dental handpieces without anti-suction should be replaced soon by those with it or comprehensive dental unit with anti-suction device should be used.
CONCLUSIONS: Used dental handpieces must be sterilized effectively before next use. Awareness on prevention from cross-infection should be improved for dental-care professional staff and operation of sterilization should be standardized.