Practice safety

02 October 2012
Volume 28 · Issue 9

Belinda Mayoh and James Holder review the regulation concerning decontamination of materials.

On page 42 of the Department of Health's HTM01-05 it clearly states that all impressions, prostheses and orthodontic appliances must be: "Decontaminated in a multi-step process to be conducted in accord with the device or material manufacturer's instructions. Immediately after removal from the mouth, any device should be rinsed under clean running water. This process should continue until the device is visibly clean. All devices should then receive disinfection according to the manufacturer's instructions. This will involve the use of specific cleaning materials noted in the CE-marking instructions. After disinfection, the device should again be thoroughly washed. This process should occur before and after any device is placed in a patient's mouth. If the device is to be returned to a supplier/laboratory or in some other fashion sent out of the practice, a label to indicate that a decontamination process has been used should be affixed to the package."

In reality this means that every time you take a dental impression it must be thoroughly rinsed, disinfected and rinsed again before it is sent to the laboratory. Likewise when you receive the crown, bridge, denture or whatever other type of appliance the laboratory has manufactured for you it must be similarly disinfected and rinsed before it is placed in the patient's mouth. If the appliance is then returned to the laboratory, for whatever reason, the same cycle must be repeated both before sending it back and before reinserting it into the patient's mouth at the next appointment. This protocol must be repeated until the patient leaves the practice with the final restoration or appliance. In between times, the laboratory will similarly be rinsing and disinfecting the impression or device upon receipt within the laboratory and before sending it back to the practice. That is a lot of rinsing and disinfecting.

Unfortunately a lot of the impression materials currently in use, especially alginate and polyether impression materials, are very moisture sensitive and so can become swollen and distorted if they remain in contact with water for too long. Similarly, some of the disinfectants currently in use are supplied in either a powder presentation, which needs to be thoroughly dissolved if it is to have the manufacturer's recommended concentration for effective disinfection - something that may not always happen in reality, or alcohol sprays where there is an obvious health risk associated with a vaporised spray, maybe even incorporating bacteria and so on. Consequently a burst of pressure from a spray can expel potentially harmful bacteria into the practice/laboratory environment, which can then possibly settle upon the surrounding surfaces and later come into contact with patients and staff, causing a serious risk of cross-contamination and infection.

The water that the impression is rinsed in must also be considered. If it is hard water, containing various calcium and magnesium impurities, these can be deposited on the surface of the impression acting as a barrier between the impression surface to be disinfected and the disinfecting agent itself. It is also well documented that these impurities reduce the efficacy of some disinfecting chemicals by forming chemical bonds and essentially deactivating them.

Therefore the ideal impression material disinfectant should have the following properties:

  • Meet all the requirements of HMT 01-05 with regards to the disinfection of impression materials, prostheses and orthodontic appliances.
  • Be safe to use (containing no allergenic or components hazardous to health).
  • Have a short working time (to avoid excessive water contact).
  • Be easy to use.
  • Be liquid rather than powder presentation – easy to mix in the correct proportions
  • Be effective in hard water.
  • And be cost effective.

PracticeSafe Soak has been specifically designed to meet all the requirements of HMT 01-05 and all the other relevant regulations and standards regarding the disinfection of impression materials, prostheses and orthodontic appliances within both the dental practice and laboratory environment.

In its recommended three per cent working concentration, when used in an ultrasonic bath, only three minutes immersion is required for disinfection. This means that the risk of alginate and polyether impressions becoming distorted due to water absorption is minimised. It also saves time for dentists and dental technicians.

Kemdent recommends that personnel responsible for disinfecting impressions using PracticeSafe Soak wear gloves to protect themselves from potentially harmful oral fluids and pathogens.

References available on request.