As we enter the winter months and flu season, dental hygienists should be reminded of ways to protect themselves from infections they may be exposed to while working in the highly-contaminated environment called the human mouth.
Most dental procedures create contaminated aerosols and splatter. For example, the use of hand scalers, prophy angles and air-water syringes produce splatter in the form of relatively large droplets, which contain potentially pathogenic organisms that are usually controlled by gloves, masks and eye protection.
Ultrasonic scalers and air polishers are the greatest producers of small particle aerosol contamination, putting hygienists at the forefront of risk for the airborne transmission of infections, according to an article written by Stephen K. Harrel, DDS, for Dimensions of Dental Hygiene.
The risk of infection occurs when these instruments are used on a patient and the visible aerosol mixes with the invisible microorganisms that arise from the patient, Dr. Harrel continued.
To be safe, it is best to avoid performing aerosol-generating dental procedures on patients who are ill or have the flu. Additionally, hygienists should follow universal precautions for aerosols on the assumption that all patients carry an infectious disease that can be spread by an aerosol route, Dr. Harrel wrote.
In discussing preventative measures, Dr. Harrel wrote that hygienists who wear gloves, well-fitting masks and eye protection will greatly lower the risk of infection.
However, a true aerosol can stay airborne for up to 30 minutes. When the larger droplets evaporate, the contamination they carry can become re-airborne as a dust particle, he added. Since the risk of contamination continues long after the dental procedure may be over, Dr. Harrel suggested that other precautions be followed, including:
1. The use of a pre-procedural rinse – such a chlorhexidine – to lower the number of aerobic bacteria in the air. However, this will not affect blood coming from an operative site or viruses coming from the respiratory tract, so this rinse should not be relied on to prevent airborne contamination.
2. The use of a high volume evacuator (HVE), which has been shown to universally reduce airborne contamination. This is a mandatory infection control precaution when using an ultrasonic scaler, according to Dr. Harrel, who also noted that a saliva ejector does not qualify as a HVE because of its small diameter.
3. Placing a barrier around the air polishing tip, combined with a vacuum, which has been shown to reduce the airborne contamination from air polishing by 97%. In fact, this is the only proven method to control the aerosols from air polishing, which are more difficult to contain because of the compressed air used during air polishing. The barrier blocks the high-speed particles from ricocheting off the teeth into the air and the vacuum removes the water and abrasive particles from the operating site.
The bottom line, according to Dr. Harrel, is that aerosols can be controlled with the appropriate precautions. Each of the suggestions above adds a layer of protection for dental hygienists and others in the dental office. For adequate protection, however, all three steps must be followed.
For more information or to read Dr. Harrel’s article, please visit http://www.dimensionsofdentalhygiene.com/ddhright.aspx?id=123.