Why surface decontamination matters

Dental practices present a set of unique challenges when it comes to infection control. Without proper infection control measures, many things within a practice, including people, dental instruments, clinical and non-clinical surfaces, can be carriers for cross-contamination and contribute to the spread of pathogens and disease.

There are two types of dental environmental surfaces: housekeeping and clinical contact surfaces. Housekeeping surfaces do not come into contact with hands or devices during dental procedures (e.g. floors, sinks and walls)[i].

Clinical contact surfaces are any surfaces that can readily become contaminated with blood or other potentially infectious materials by gloved hand, aerosol, contaminated instruments or other items in the course of providing dental care[ii]. Examples of clinical contact surfaces include: light handles, chair control buttons, X-ray equipment, computer keyboards, handpiece hoses, headrests and reusable containers of dental materials.

Cleaning protocols

As stated in HTM 01-05 and SHTM 01-05, every dental practice should have a nominated lead member of staff responsible for infection control and decontamination. This role includes ensuring all clinical staff are following the infection control policy, are receiving the relevant training, and ensuring all policies and processes are up to date.

HTM 01-05: 6.54 also states that “the dental practice should have a local protocol clearly outlining surface- and room-cleaning schedules”, while SDCEP states practices “should have in place a schedule and instructions for the cleaning of non-clinical areas of the practice (e.g. the waiting room, patients’ toilets)” [iii].

Cleaning v. disinfection

Cleaning and disinfection are key components of a practice’s infection control policy. Cleaning is the removal of visible soil (e.g. organic and inorganic material) from objects and surfaces and is normally achieved manually or mechanically using water with detergents or enzymatic products.

Disinfection is the inactivation or destruction of microorganisms that cause disease, which include viruses, bacteria and yeasts, on inanimate objects and surfaces[iv].

The presence of biofilms, the substances used in the cleaning process, and the method and frequency of cleaning, all interfere with the extent to which microorganisms resist cleaning and disinfection procedures. The transmission of microorganisms from a contaminated surface to a clean one can occur if the cleaning method is not correct[v].

Products that accomplish both cleaning and disinfection in one application offer an efficient ‘one-stage’ approach and are effective in most clinical situations. However, the chemical composition of some disinfectants prevent them from being good cleaners and require pre-cleaning, followed by disinfection, hence a two-stage approach.

The problem of alcohol

Disinfectants containing ethyl alcohol and/or isopropyl alcohol have been widely used for disinfecting environmental surfaces in healthcare settings for many years, and are especially effective against viruses, including influenza viruses, Ebola viruses and several coronaviruses[vi].

However, while alcohol is a very good disinfectant, it is not effective as a cleaner, especially on proteinaceous soils. It evaporates rapidly in use, limiting the effective contact time, and is highly flammable.

Alcohol also acts to fix proteins to surfaces, a problem highlighted in HTM 01-05 Section 6.57 that states: “Alcohol has been shown to bind blood and protein to stainless steel. The use of alcohol with dental instruments should therefore be avoided.”

Where extensive soiling matter is present, its removal is important so disinfection can take place. If proteins are present and an alcohol solution is used as a disinfectant, proteinaceous material can be fixed to the surface, potentially trapping microorganisms and providing additional surface roughness to aid adhesion of further soiling[vii].

It is essential that all biological matter is removed from dental instruments in order for effective sterilisation to take place. If biological matter is not removed prior to sterilisation it will become ‘baked on’ to the instrument during autoclaving, rendering it non-sterile and therefore requiring the decontamination process to be repeated.

Material compatibility

When cleaning and disinfecting practice surfaces, material compatibility is an important consideration as there are many different materials to take into account. Different surfaces can impact on the performance of products due to variations in texture, porosity, and material properties, making it crucial to verify their efficacy on each surface type[viii]. Any damaged surfaces also make it more difficult to decontaminate successfully.

Alcohol is known to be incompatible with common surgery surfaces such as PMMA and upholstery, including the vinyl or synthetic leather used on dental chairs and stools, which is vulnerable to drying and cracking when exposed to alcohol-based sprays. Prolonged and repeated use of alcohol as a disinfectant can also cause discolouration, swelling, hardening and cracking of rubber and certain plastics[ix].

ABS plastic and polycarbonate commonly used in delivery systems and housing units of dental equipment may degrade or discolour with prolonged exposure to certain chemicals.

Hydrogen peroxide, a commonly-used oxygen-based cleaning agent can dull or bleach some finishes[x]. To avoid any potential damage, users should always follow manufacturer’s guidance for surface compatibility of any cleaning/disinfectant agent before application to the various surfaces across the dental practice.

The use of an alcohol-free product alone though does not automatically guarantee excellent material compatibility. Dental chairs are made from a number of sensitive materials and even some alcohol free chemistries can cause problems. Therefore, the balance of efficacy and careful selection of a compatible product is paramount, especially in dentistry, in which frequency and repeated use can compound material compatibility issues quickly.

Product selection

Domestic cleaning products should never be used in a dental surgery as they lack appropriate properties and can damage sensitive surfaces. Practices should always use products designed for clinical environments that conform to regulatory guidelines to keep patients and staff safe and equipment functioning correctly.

Efficacy is the single most important criteria for dental professionals when it comes to infection control products. As a leading dental infection control manufacturer, Dentisan has been at the forefront of providing clinically-proven decontamination products created specifically to comply with local and regulatory guidelines.

These include alcohol-free, pH neutral surface cleaners such as Biocleanse Ultra that cleans and disinfects in one step with proven efficacy against bacteria and yeasts. Biocleanse Ultra liquids are CE marked, HTM 01-05 compliant, and are compatible with a broad range of materials including PMMA and aluminium. These products help to streamline processes while ultimately making it easier for practices to run a fully compliant decontamination operation and mitigate any likelihood of contracting an infection in the dental surgery.