As the dental profession is only too well aware, cleaning and disinfection processes within the dental practice are of paramount concern, not only in relation to Care Quality Commission and HTM01-05 compliance, but also with regard to staff and patient well-being – which the compliance guidelines are there to ensure and protect.
Protein contamination in the dental surgery is an obvious area for serious concern, since residual soiling on surfaces can harbour pathogens. Blood has the potential to carry and transmit viruses such as HIV, HBV and HCV. The risk of transmission of communicable blood-borne viruses might be considered to come only from high risk areas such as accidental sharps injuries, but greater research and advances in the sphere of microbiology now provide evidence that many micro-organisms can survive on a variety of surfaces, making the danger of disease transmission from contaminated surgery surfaces or equipment a genuine threat to patients and staff. In addition, an increasingly mobile population including greatly increased economic migration, has resulted in a resurgence of diseases such as TB, which are associated with overcrowding and poor standards of general health.
To overcome the potential issue of surface decontamination and the prevention of transmission of pathogens, dental practices must have rigorous infection control policies which establish clear protocols for cleaning and disinfection and document the practice's adherence to the procedures laid down.
Decontamination is defined by the MHRA as a combination of processes which removes or destroys contamination so that infectious agents or other contaminants cannot reach a susceptible site in sufficient quantities to initiate infection or other harmful response. Within a dental surgery, both cleaning and disinfection are required but although the terms are often confused they are not the same thing. Cleaning involves the physical removal of soiling matter from surfaces while disinfection refers to the inactivation of pathogens. Cleaning must take place before disinfection to ensure that bacteria, proteins and other contaminants are removed from surfaces before disinfection takes place, unless an effective single stage process is in use.
Decontamination of a specific area is aided by the use of commercially available products and many of these agents are based on alcohol. In dentistry, alcohol has been widely adopted as a disinfectant for many years and its efficacy in this role is well documented.
The widespread use of alcohol as a disinfectant in dentistry has been largely driven by its low cost and quick drying properties, where its rapid drying is perceived as beneficial in achieving a short turn-round time between patients. However, rapid evaporation of alcohol based products also means that by the time the treatment of a surface has been completed, most of the alcohol has evaporated meaning that the areas wiped at the end of the process will be neither cleaned nor effectively disinfected (fig 1). Despite the acknowledgement of alcohol as an effective disinfectant, it is not effective as a cleaner, particularly where protein based soils are present as is likely to be the case in medical and dental environments. This fact is frequently overlooked, but is referenced in HTM 01-05 guidelines section 6.57 of HTM01-05: 'Care should be taken in the use of alcohol wipes, which – though effective against viruses on clean surfaces – may fix protein and biofilm. However, the careful use of water with suitable detergents, including those CE-marked for clinical use, is satisfactory provided the surface is dried after such cleaning. Note: Alcohol has been shown to bind blood and protein to stainless steel. The use of alcohol with dental instruments should therefore be avoided.'
We can conclude from this that alcohol based products are not suitable for single stage cleaning and disinfection in an environment where protein based soils are likely to be present and to ensure compliance with HTM01-05 should only form part of two-stage process.
1. Clean to remove physical soiling
2. Disinfect with alcohol to inactivate pathogens
This process however is less than desirable from an operational point of view due to the additional time required to carry out two procedures between each patient, as well as the additional cost of buying two products and the additional inventory required.
There are a number of key variables that in practice might influence the effectiveness of any cleaner/disinfectant and these include the type of surface material, the soiling that is present and of course the method and physical action used to clean, which varies with every individual. But one method of measuring effectiveness despite these variables is the efficacy of a product in terms of its contact time and in tests, the difference between alcohol and water based products are clear.
The graph (fig 2) illustrates the behaviour of water and alcohol based formulations. Each product type achieves its maximum effectiveness on immediate contact with the surface. However the rapid evaporation of alcohol based products quickly reduces their effectiveness so that after around one minute there are no effective cleaning or disinfection properties. In comparison, as the water based product starts to dry, it becomes more concentrated and its disinfection properties become increasingly effective, lasting more than twice as long.
Further limitations in the use of alcohol based products such as material incompatibility and flammability that makes storage a consideration in terms of health and safety, may lead us to question why alcohol has been such a popular choice for dental practices. Of course the low cost and quick drying properties referenced earlier have been key drivers in this market, but so too has the lack of a viable alternative.
In recent years a growing demand for water based products and the advent of HTM 01-05 has provided manufacturers with the necessary impetus to develop a solution that ticks all the boxes, without the need to compromise in any area. The ideal is a carefully formulated water based product that can both remove soiling and disinfect in a single process, is highly effective and compatible with a broad range of materials. Such a solution will greatly reduce the time taken in practice and deliver an effective answer that responds to the demands of the market and provides a means of ensuring complete compliance with current guidelines.