Verification of Sterilization

Heat Sterilization (Spore Testing)

Dental instruments pose a threat of cross-contamination between patients if the instruments are not sterilized between uses. Consistent killing of bacterial spores by a sterilizer provides the best known assurance that sterilization (death of all microorganisms) has occurred and that the device is functioning properly.

At least once per week, each steam, dry heat, or chemical sterilizer will be checked with a biological control indicator. Control indicators are indispensable in checking against faulty packaging, loading, and sterilizer performances. Physical controls such as pressure gauges and thermometers are widely used but should be considered secondary methods of monitoring the efficacy of sterilization.

Steam Sterilization

The biological indicator to be used for steam sterilization is Bacillus stearothermophilus spores. Use spore strips or ampules with an average population of 104 to 106 Bacillus stearothermophilus organisms. The spores should be killed at 2500 F in thirty minutes with steam sterilization.

Dry Heat Sterilization

The proper organism to use for testing dry heat sterilization processes is a spore strip/ampule with Bacillus subtilis var. containing 106 organisms.

Glutaraldehyde Sterilant Solutions

The effectiveness of the glutaraldehyde method cannot be routinely verified during use. Therefore, this or any other disinfection method, must not be substituted for a verifiable sterilization method unless the instruments would be destroyed by high heat methods. Verifiable heat or gas sterilization methods provide the most effective way to insure dental instrument safety.