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Sterilization beneath rings on dental instruments
1Department of Oral Microbiology, Indiana University School of Dentistry, Indianapolis 46202.
Abstract:
This study determined the effectiveness of standard methods of instrument sterilization beneath instrument rings. Sets of three types of dental instruments were contaminated with known amounts of bacterial spores (Bacillus stearothermophilus or Bacillus subtilis). Instrument rings were placed over the contamination and the instruments processed through standard cycles in a steam autoclave, an unsaturated chemical vapor sterilizer, a standard dry heat sterilizer, an ethylene oxide gas sterilizer or a 2.0% alkaline glutaraldehyde solution. Controls consisted of spore-contaminated instruments without rings that were not processed through any sterilizing method and that were processed through each sterilizing method. All instruments and their associated rings were cultured for the presence of live spores. The results indicate that the reliability of sterilization beneath the instrument rings used is greatest if the ringed instruments are processed through a steam autoclave or an unsaturated chemical vapor sterilizer.
Insights
Instrument rings can hinder sterilization effectiveness. Steam autoclaves and unsaturated chemical vapor sterilizers offer the greatest reliability for sterilizing instruments with rings.
Area of Science:
- Dental instrument reprocessing
- Sterilization validation
- Microbial contamination control
Background:
- Instrument rings are common in dental settings.
- Potential for microbial contamination beneath instrument rings is a concern.
- Standard sterilization methods may be compromised by instrument accessories.
Purpose of the Study:
- To evaluate the efficacy of common sterilization methods for instruments with attached rings.
- To determine if instrument rings impede effective sterilization.
- To identify optimal sterilization parameters for ringed dental instruments.
Main Methods:
- Dental instruments were contaminated with bacterial spores (Bacillus stearothermophilus/subtilis).
- Instrument rings were placed over contamination sites.
- Instruments were processed using steam autoclave, unsaturated chemical vapor, dry heat, ethylene oxide, or glutaraldehyde solution.
- Post-sterilization cultures assessed for viable spores on instruments and rings.
Main Results:
- Sterilization effectiveness varied significantly between methods.
- Steam autoclaving and unsaturated chemical vapor sterilization demonstrated the highest reliability for ringed instruments.
- Dry heat, ethylene oxide, and glutaraldehyde showed reduced efficacy in sterilizing beneath instrument rings.
Conclusions:
- Instrument rings can create challenges for complete sterilization.
- Steam autoclave and unsaturated chemical vapor sterilization are recommended for instruments with rings.
- Careful consideration of sterilization methods is crucial when using instrument accessories.