What are the requirements for sterilization monitoring?

Sterilization procedures are routinely monitored using a combination of mechanical, chemical, and biological indicators (BIs). Taken together, these indicators evaluate the sterilizing conditions and effectiveness of the process. Because BIs directly monitor sterilization by assessing the process’ ability to kill known highly resistant bacterial spores (e.g., Geobacillus or Bacillus species), rather than only testing the physical and chemical conditions necessary for sterilization, the use of calibrated BIs remains the accepted “gold standard” for monitoring. The calibrated spores used in these biological monitors are more resistant and present in much higher concentrations than the common microbial contaminants found on patient care equipment. As a result, an inactivated BI indicates that other potential pathogens in the load have been killed.

The CDC (Centers for Disease Control and Prevention) recommends that correct functioning of sterilization cycles should be verified for each sterilizer using a BI and control at least once a week. Virtually every state has taken this quality control recommendation from the CDC and turned it into a requirement for most health care settings, including dental practices. In addition every load containing implantable devices should be biologically monitored, and the items quarantined until BI results are known. The importance of routine biological monitoring cannot be overemphasized, as BIs can ascertain the effectiveness of many of the steps involved in instrument reprocessing. Although multiple studies have shown that the most common cause of sterilization failures is human error, other problems can compromise sterilizer efficiency, such as

• improper pre-cleaning, organic debris,
• incorrect or excessive packaging,
• overloading the sterilizer,
• improper time, temperature and pressure parameters, and
• inadequate sterilizer maintenance.