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Dentistry often involves procedures that employ 3-way syringes, high-speed handpieces and ultrasonic scalers, the use of which can generate aerosols, droplets and spatter containing patients' blood, plaque, saliva and tooth and dental materials. This increases the chances for cross-contamination.1,2
A variety of processes can be used to minimize splashing, spraying, spattering and droplet formation. Examples include:
The possibility of aerosol and spray contamination requires both environmental and practitioner protection. This would include clinical surface barriers (covers) and proper environmental disinfection. Personal protective equipment (PPE), such as gloves, masks, protective eyewear and gowns, reduces exposure of skin, mucous membranes and non-clinical attire.1,2
Adenosine triphosphate (ATP) is a primary source of energy and is present in all living, metabolically active cells, including bacteria, fungi and protozoa. The ATP bioluminescence assay is a simple, rapid, highly sensitive technique used to quantify ATP levels. It is based on a luciferin-luciferase reaction. A specialized swab is used to sample a standardized surface area, which is then analysed using a portable hand-held luminometer. The total amount of ATP, both microbial and non-microbial, is quantified and expressed as relative light units. Levels of ATP bioluminescence have been correlated with bacterial counts.3
The assay is probably the most widely used technique in the food and beverage industries for hygiene monitoring and cleaning validation (measurement of the removal of bioburden). The assay is also used to monitor disinfection/cleaning in healthcare facilities.3
A recent study investigated the amount of patient body fluids on a variety of PPE surfaces before and after certain dental procedures. Specifically, the spread of aerosols and spatter generated during ultrasonic scaling followed by mechanical prophylaxis was measured.4
Clinical procedures were performed by dental hygiene students during a 20-minute period. ATP values were determined before and after prophylaxis for standardized (25 cm2) surface areas of student masks, protective eyewear, dominant arm and chest of long-sleeved clinic gowns, as well as patient protective eyewear.
Contamination on every surface tested increased significantly after dental treatments. Highest levels of contamination were found on patient protective eyewear. After cleaning with cotton containing 70% alcohol, ATP scores on contaminated patient and student eyewear returned to pre-procedural levels.
Dental practitioners can become contaminated occupationally. If not correctly managed, contamination can spread throughout the workplace or could even be transported home. PPE provides a barrier against contamination of skin, mucous membranes and street clothes. All PPE must be removed before leaving the workplace.5
In the United States, employers are responsible for providing, maintaining and cleaning PPE. Re-usable PPE, such as gowns, jackets, scrubs and uniforms, cannot be taken home and laundered. They need to be laundered in-house or sent to a medical laundry service.1,5
Shoes can also become contaminated. It may be easiest to reserve a pair for clinical use only, that would never be taken home. Also, items such as purses, coats, sweaters, boots and packages brought from home can become contaminated if not properly stored or handled. These should be kept in non-clinical areas and never handled with contaminated hands.5