CDC Sterilization RECOMMENDATIONS

The CDC recommendations state: Correct functioning of sterilization cycles should be verified for each sterilizer by the periodic use (at least weekly) of biological indicators (BIs or Spore Tests). Consideration should be given for more frequent testing if the sterilizer is used multiple times each day or with use of a variation of sterilization cycles. Users should follow the manufacturer's directions concerning the appropriate placement of the BI in the sterilizer; the preferred area for the BI placement is in the area of most challenge of the sterilizer (where air pockets are most likely to occur)--often near the door or the middle of the load near the drain.

In addition to conducting routine biological monitoring, equipment users should perform biological monitoring for the following occurrences:

• Whenever a new type of packaging material or tray is used;
• After training new sterilization personnel;
• After a sterilizer process failure is indicated by a failed (positive) BI+;
• After a sterilizer has been repaired;
• After any change in the sterilizer loading procedures;
• During initial use of a new sterilizer;
• After relocation of an existing sterilizer; and after electrical/power source failure.

Biological Indicators 
In comparison to Chemical Indicators, Biological indicators (BIs) commonly use highly resistant spores (i.e., spore test) to challenge the sterilization process. Since they are more resistant and are usually present in greater numbers than are the common microbial contaminants found on instruments, destruction of these organisms will indicate destruction of other potential pathogens. While all three types of monitoring are important to the quality assurance process, biological monitoring is considered the gold standard for sterility assurance.

The most commonly used forms of BIs in dentistry are spore strips, and self-contained spore vials. Self-contained vials have a glass ampule of sterile media, which is encased in a plastic vial with a spore strip inside. After sterilization, the vial is crushed—allowing the media to come into contact with the spore strip and then incubated. With either the strips or vials after incubation, if the pH indicator in the growth media changes the color from purple to yellow, this is an indication of a positive culture (i.e., spore growth) and meaning a failed test. It is CDC recommended that a control be conducted with every BI test.

Three options are available for monitoring sterility assurance in the dental office:

• mail-in sterilization monitoring services to a third-party testing laboratory (i.e., private companies or dental schools)
• in-office 24-hour monitoring systems
• and a newly released in-office 10-hour monitoring system

Crosstex is proud to offer the ConFirm® 10 In-Office Incubator, with spore growth detected in as few as 3-5 hours with final results in 10 hours. While some offices prefer use of a professional lab for testing verification (i.e., gram staining) and third-party documentation of results, others appreciate the convenience in-office processing provides, with a direct turnaround time and without the challenge of mailing and waiting for results. It should be noted that in-office monitoring systems can only be used with steam (autoclave) sterilizers; mail-in monitoring services can provide results for steam, dry heat, chemical vapor, and EtO.