| FAQ - Instruments & Equipment - 2014
I would like to find out what the protocol is for disinfecting disposable impression trays if they have been tried in & not used for the impression because they weren’t the right size.
A relevant section of the 2003 CDC guidelines for infection control in dentistry that should be noted states as follows:
Patient-care items (dental instruments, devices, and equipment) are categorized as critical, semicritical, or noncritical, depending on the potential risk for infection associated with their intended use (Table 4) (242). Critical items used to penetrate soft tissue or bone have the greatest risk of transmitting infection and should be sterilized by heat. Semicritical items touch mucous membranes or nonintact skin and have a lower risk of transmission; because the majority of semicritical items in dentistry are heat-tolerant, they also should be sterilized by using heat. If a semicritical item is heat-sensitive, it should, at a minimum, be processed with high-level disinfection (2). 1
The disposable or single use impression tray is considered a semi-critical item. Semi-critical items require sterilization between patients. If the impression tray has been used in the mouth and it is the wrong size, it has still been used intraorally and it is contaminated. Disinfection is not equivalent to sterilization:
Disinfection: Destruction of pathogenic and other kinds of microorganisms by physical or chemical means. Disinfection is less lethal than sterilization, because it destroys the majority of recognized pathogenic microorganisms, but not necessarily all microbial forms (e.g., bacterial spores). Disinfection does not ensure the degree of safety associated with sterilization processes. 1
If the manufacturer of the impression tray does not specify that the item can be sterilized (i.e., it is autoclavable), then the item is not suitable for reuse between patients.
Disposable items such as disposable impression trays are manufactured for a single use or for the use on one patient only, and should not be reprocessed because they are not designed or intended for reuse.
It is also very relevant and important to note that the 2003 CDC guidelines for infection control in dentistry states:
A single-use device, also called a disposable device, is designed to be used on one patient and then discarded, not reprocessed for use on another patient (e.g., cleaned, disinfected, or sterilized) (383). Single-use devices in dentistry are usually not heat-tolerant and cannot be reliably cleaned. 1
Infection Control and Management of Hazardous Materials for the Dental Team states:
Single-Use (Disposable) Devices
One should use single-use devices for one patient only and should dispose of them appropriately. 2
Practical Infection Control In Dentistry also states:
A disposable, or single-use, device is designed to be used on one patient and then discarded. Disposable items are not intended to be cleaned and sterilized for reuse on another patient, because they are usually not heat-tolerant and cannot be reliably cleaned. The labeling on the single-use item may or may not identify the device as single-use or disposable, and does not include instructions for reprocessing. In other words, if an item in not labeled single-use or disposable and does not include instructions for reprocessing, it should be used once and disposed of appropriately. 3
In summary, regarding impression trays that are used intraorally (even those that were just tried for size), after single patient use if they are designated as disposable or single-use they should be disposed of appropriately and not reprocessed. The manufacturer's approved written instructions for use (IFU) should always be followed.
1) Kohn WG, Collins AS, Cleveland JL, Harte JA, Eklund KJ, Malvitz DM, Centers for Disease Control and Prevention (CDC). Guidelines for infection control in dental health-care settings—2003. MMWR Recomm Rep 2003;52(RR-17):1-61. http://www.cdc.gov/mmwr/preview/mmwrhtml/rr5217a1.htm Accessed on February 19, 2014.
2) Miller CH. Infection Control and Management of Hazardous Materials for the Dental Team, 5th edition. Elsevier/Mosby Publishers. Page 86.
3) Molinari JA and Harte JA. Practical Infection Control In Dentistry – Third Edition. Wolters Kluwer / Lippincott / Williams & Wilkins. Page 233.