The importance of decontamination: sterilization preliminaries

In order to protect patients and medical staff in dental practices from contamination, it is necessary to put in place decontamination procedures to make the environment and equipment sterile. Pursuant to Italian Legislative Decree 81/2008 for the protection of the workforce, employers are responsible for introducing appropriate sterilization and decontamination systems.

In particular, because they come into contact with mucous membranes and blood, straight after use any instruments and medical items that are likely to be reused must be treated in order to eliminate all potentially pathogenic microbes and bacteria that might otherwise be transferred to third parties.

Established procedures must be followed during the decontamination process. The following must be done in order:

• The instruments must be placed in special containers.
• They must be decontaminated with chemical or physical agents. In the former case, this means immersing them in a disinfectant solution (usually a 3.4% polyphenol solution) for at least 20 minutes. In the latter case, steam is used. The disinfectants must guarantee protection from HBV, HCV, HIV, TB and fungi.
• After the decontamination procedures, the staff must clean and dry the instruments in complete safety. They may be washed manually with brushes or mechanical means.
• The step after drying is sterilization. First of all, the instruments are placed in sterile pouches with two layers, the first of which is made of transparent plastic film and the second of which is made of paper with open cells. The steam is able to penetrate thanks to the open cells. After the instruments have been bagged, they must be placed inside an autoclave for sterilization and vacuum creation. The heat produced results in thermal shock that closes the open cells and therefore prevents air from getting in after the sterilization stage. This stage must ensure that the instruments cannot be contaminated by external agents in any way until they are subsequently reopened for use.
• Marking: after they have been sterilized, the sealed pouches must be marked to ensure that the decontamination procedures are traceable. The sterilization lot and the date must be stated.

Decontamination and sterilization procedures are an effective way of ensuring that diseases are not spread in a dental practice, but the procedures themselves also need to be checked: it is necessary to carry out tests to assess whether the autoclave is operating effectively. For example, Bowie & Dick tests are performed for porous accessories such as gauzes and gowns, and Helix tests are carried out for hollow items such as wands and turbines. It is an inexpensive, simple way of assessing the efficiency of decontamination procedures and establishing whether the equipment requires any maintenance.

The regulations state that tests must be performed:

• If an autoclave is not used for long periods.
• After maintenance procedures.
• On a regular, ongoing basis, depending on the use of the autoclave.

The results of the tests must be recorded and saved by the professional figure responsible and they can be used as proof that decontamination procedures have been carried out correctly in any court proceedings.