​Infection prevention and control is vital to the safe and effective treatment of dental patients.

Infection prevention and control is vital to the safe and effective treatment of dental patients.

It is also key to providing a safe working environment for all staff. Adopting measures that reduce the likelihood of transmission of healthcare-associated infections must be part of practice policy. This should include recommendations for the cleaning of surfaces in the dental treatment room.

HTM 01-05 6.61 states that: ‘The patient treatment area should be cleaned after every session using disposable cloths or clean microfibre materials – even if the area appears uncontaminated.’ Surfaces should be wiped down between patients with an effective disinfectant. Disposable, single use wipes impregnated with disinfectant are usually the preferred choice, as extensive microbial contamination has been found on reusable cleaning cloths. This means that wiping hard surfaces with a non-disposable cloth can contaminate hands, equipment and other surfaces. [Rutala, 2008]

HTM 01-05 recommendations

6.46 All work surfaces where clinical care or decontamination is carried out should be impervious and easily cleanable.

6.54 The dental practice should have a local protocol clearly outlining surface- and room-cleaning schedules

6.61 The patient treatment area should be cleaned after every session using disposable cloths or clean microfibre materials – even if the area appears uncontaminated.

Whilst the HTM 01-05 recommendations apply to England; Scotland, Northern Ireland and Wales follow similar principles in many of these areas.

Wipes pre-saturated with the disinfectant of choice are convenient to use, disposable and require less storage space than other methods. They also have the additional advantage of containing the optimum amount of disinfectant to ensure efficacy.

Cleaning and disinfection are not the same

It is the responsibility of everyone working in the practice to ensure that surfaces are cleaned and disinfected. Cleaning refers to the removal of soil and organic contamination from a surface and removes large numbers of microorganisms. Cleaning is designed to remove organisms rather than kill them and should always precede disinfection. Cleaning helps to ensure the efficacy of disinfection. Following the cleaning stage, the disinfectant phase eliminates many or all pathogenic microorganisms, except bacterial spores from the surface – depending on the type of disinfectant used.

Disinfection is the process of using a chemical, with proven anti-bacterial, anti-virucidal and anti-fungal characteristics to kill or to inactivate microorganisms to a level that should not be harmful to patient or staff health.

Surface cleaning – a two-stage process

When cleaning contaminated surfaces, it is recommended that a double wipe procedure is used. The first wipe cleans the surface and physically removes contaminants including dust, soil, large numbers of micro-organisms and the organic matter that protects them. The second wipe disinfects the surface; reducing the number of microorganisms to a safe (or relatively) safe level.

The initial cleaning stage is essential to remove any visible soil from the surface, as it may compromise the disinfectant process. Organic matter such as serum, blood or pus can interfere with the antimicrobial activity of disinfectants, meaning that the disinfectant is less effective. Organic material can also protect microorganisms from attack by acting as a physical barrier [Rutala, 2008].

Successful surface cleaning can only be achieved by closely following the manufacturer’s specifications for use. The following instructions refer to the correct use of mikrozid wipes – ‘Gloves should always be worn before using a ready-to-use pre-soaked wipe. The wipe is removed from the container by tearing off at a downward angle. The surface should be wiped thoroughly, ensuring that the surface is completely moistened. The surface should be allowed to dry, before a second wiping procedure is used to ensure that the surface is effectively decontaminated.’

Each wipe should only be used once and on one surface. It may be necessary to use several wipes for large surface areas. Wiping in figure of eight loops is recommended to ensure that the complete surface area is covered.

Wipes and gloves should be correctly disposed of after use.

Selecting disinfectants

Spectrum of activity

Ideally the chosen disinfectant should have a high inactivating capacity for a broad range of viruses, including HIV and Hepatitis, as well as being effective against bacteria, including tuberculosis. It should be safe to use and suitable for frequent application. [Sandle, 2014] There are two main types of disinfection available for wiping hard, non-porous surfaces: those that are alcohol based and those that are non-alcohol based. The non-alcohol ones are usually based on quaternary ammonium compounds (sometimes known as ‘quats’) and the ammonium salts disrupt the cell membranes of the bacteria. Alcohol-free formulations are generally regarded as ineffective against TB bacteria and non-enveloped viruses such as polio.

Whereas alcohol based disinfectants are rapidly bactericidal, they are also tuberculocidal, fungicidal and virucidal. [Rutala, 2008] Alcohol based surface disinfectants possess some of the widest disinfectant kill ranges available. They are virucidal against ‘enveloped’ viruses, such as HIV and hepatitis B and against the ‘non-enveloped’ viruses, such as Poliovirus, Rhinoviruses and Hepatitis A. [Sandle, 2014]

Safety

Disinfectants should be safe for staff to use (using recommended PPE), be compatible with the surfaces on which they are used and can be easily disposed of without harming the environment.

Speed of action

They should also have a short ‘contact time’. This is the time in which the disinfectant needs to remain in contact with the surface to kill or inactivate microorganisms. [Sandle, 2012] Both quats and alcohols have fairly rapid contact times, requiring less than a one minute contact time.

Removal of surface protein

Surfaces may contain protein residues, such as blood and pus and it is important that disinfection effectively removes any protein present. Alcohol based disinfectants can, in occasional situations bind proteins to stainless steel. However, this effect has only been demonstrated after a prolonged contact time of over 10 minutes – a period of time, which is far in excess of the wiping process required to disinfect practice surfaces. [Prior, 2004] In addition, very few practices have surfaces made of stainless steel.

When a double-wiping procedure is adopted, alcohols are as effective as quats on surfaces containing protein residues. The first wipe removes the protein and the second brings the alcohol disinfectant into contact with any remaining microorganisms. [Lawrence, 1992]

Conclusion

Prevention of cross infection is integral to good dental practice. This includes disinfecting surfaces, especially between patients to eliminate pathogenic microorganisms, like TB or MRSA bacteria.

There are many types of disinfectants to choose from and this article has examined some of the considerations when selecting the most appropriate dental practice surface disinfectant.

References

HTM 01-05, ‘Decontamination in primary care dental practice’ the Department of Health (England), 2013

Lawrence, C. (1992) Testing alcohol wipes, Nurs Times, 88(34):63-4, 66

Prior, F., Fernie, K., Renfrew, A. and Heneaghan, G. (2004) Alcoholic fixation of blood to surgical instruments, J Hosp Infect., 58(1):78-80

Rutala, W.A. and Weber, D.J. (2008) HICPAC. Guideline for Disinfection and Sterilization in Healthcare Facilities, Centers for Disease Control, Atlanta, USA

Sandle, T. Cleaning and Disinfection. In Sandle, T. (2012). The CDC Handbook: A Guide to Cleaning and Disinfecting Cleanrooms, Grosvenor House Publishing: Surrey, UK, pp1-31

Sandle T, 2014, Are alcohol wipes effective in the presence of protein?; The Dentist

Clare Clark, BSc (Hons) Microbiology, ACIST, MRB is technical support manager with schülke UK.

Author: