Infection is an important element of practicing dentistry, but can often be confusing to practiioners. In our last issue of Practice Tips, we discussed the importance of cleaning before sterilization, which means an instrument must first be free of “gross debris” before it can be rendered "sterile" per the CDC guidelines.
The guidelines provide us with a wealth of information. They also indicate what items need to be sterilized after use (or disposed of if they cannot be sterilized). The CDC refers to instruments that must be sterilized as “critical.”
In determining what items should be considered “critical” in a dental office, the CDC worked closely with the ADA and have included the ADA recommendations in their guidelines:
“The American Dental Association recommends that surgical and other instruments that normally penetrates soft tissue or bone (e.g., extraction forceps, scalpel blades, bone chisels, periodontal scalers, and surgical burs) be classified as critical devices that should be sterilized after each use or discarded.”
The above recommendation is fairly straight-forward and common sense in nature. The CDC makes it very clear what needs to be sterilized in the dental office.
Something they specifically mention are dental handpieces (usually just high-speed). They are required to be sterilized, even though they do not directly penetrate tissue or bone: “Handpieces can be contaminated internally with patient material and should be heat sterilized after each patient. Handpieces that cannot be heat sterilized should not be used.” Thus, handpieces should also be considered “critical” instruments.
It’s important to be mindful of how an instrument has been used to determine how it needs to be treated.
It is equally important to note that it is the CDC who defines what is considered "sterile". To be considered “sterile” an instrument must be subjected to heat (with the exception of EO gas which is outside the scope of dentistry). In most offices, this means autoclaving, although chemical vapor sterilizers (Chemclaves) and dry heat sterilizers can often be used as well.
Dry heat sterilizers operate at a much higher temperature, so consult your owner’s manual, the manufacturer, or the dealer from whom you procured a given item to determine if it can withstand dry heat sterilization before you sterilize an instrument in a dry heat sterilizer.
As the name implies, dry heat sterilizers don't use water or vapor, so the instruments that are sterilized using dry heat will not corrode as readily as they could from the application of steam. However, the lack of steam to penetrate instruments and orifices means items must be sterilized at a higher temperature for a longer duration (i.e. cycle time) than with a vapor sterilizer. Longer cycle times can have a significant impact on instruments with lower heat-resistance, so be careful about what you place in a dry heat sterilizer. Some items (like handpieces) cannot be sterilized using dry heat. For items that will withstand dry heat (most hand instruments) the lack of moisture will allow you to get a much longer life out of your instruments and their edges (like those on scalers or scalpels) will stay sharper longer. If you have a number of instruments that can withstand the higher temperatures, dry heat can be a wonderful addition to an office’s sterilization equipment.
The CDC has a wealth of helpful information you should familiarize yourself with. Be critical about what instruments you sterilize and what you disinfect. Keep in mind how an instrument is used to determine how it needs to be treated after use. If it can withstand the heat of sterilization, sterilize it!