| FAQ - Instrument Processing - Archived Through 2012
Is dry heat equally effective in killing microorganisms as steam autoclaves?
Dry heat sterilizers have been used effectively in dental office for many years. Just as with any other sterilization method, dry heat sterilization is highly dependent upon the operator following the manufacturer's instructions for cycle time, temperature, instrument packaging, and loading technique. Because dry air is not as efficient a heat conductor as moist heat at the same temperature, a much higher temperature is required for a dry heat unit to accomplish sterilization.(1).
There have been some recommendations that dry heat be used only in situations where moist heat is not desirable due to the material, such as oils, powders, sharp instruments and glassware(2). However, the same source points out that dry heat provides excellent penetration and prevents the corrosion of metals. Since forced-air dry heat systems have very short sterilization cycles and are kind to high carbon steel instruments, they are very often used in orthodontic practices to re-process pliers and cutters.(2)
Keep in mind that the only way to assure that sterilization parameters are routinely met is to use spore tests/biological monitors. Weekly testing is recommended.(2-4)
1) Molinari JA, Rosen S, Runnells RR. In Cottone JA, Terezhalmy GT, Molinari JA, eds. Practical Infection Control In Dentistry, 2nd edition. Philadelphia:Williams & Wilkins, 1996
2) Josly L. In Block SS, ed. Disinfection, Sterilization, and Preservation, 5th edition. Philadelphia: Lippincott, Williams and Wilkins. 2001
3) CDC. Recommended Infection Control Practices for Dentistry. MMWR Morbid Mortal Weekly Report 1993;42(RR-8):1-14. Available at http://www.cdc.gov/mmwr/preview/mmwrhtml/00021095.htm
4) ADA Council on Scientific Affairs and ADA Council on Dental Practices. Infection Control Recommendations for the Dental Office and Dental Laboratory. J Am Dent Assoc 1996;127:672-680.
5) OSAP. Infection Control for Dentistry Guidelines, September 1997. Available at http://www.osap.affiniscape.com/resources/IC/icguide97.htm