The most imporant barrier

Sept. 1, 2003
For the dental healthcare professional, there is no more personal or vital barrier of protection than the face mask. As significant as the face mask is, however, few know much about them or the fact that not all face masks are equal.

When it comes to protection in the operatory, your face mask choice is critical

By Andrew G. Whitehead

For the dental healthcare professional, there is no more personal or vital barrier of protection than the face mask. As significant as the face mask is, however, few know much about them or the fact that not all face masks are equal.

In their article, Surgical Face Masks: Their Role in Controlling Cross-Contamination in Dentistry, Richard I. Karpay, DDS and Peggy Gragg, DDS, MPH, wrote, "Both oral and nasal mucous membranes can serve as a portal of entry for bloodborne or other potentially infectious material. Face masks are used as filters which protect the oral and nasal mucous membranes of dental healthcare workers from exposure to splash and spatter of patient blood U as mandated by OSHA. The protection provided by a surgical face mask depends upon the amount of aerosol that penetrates through the filter material U Masks should cover mouth and nose for protection from splash and spatter; should provide a snug fit at the periphery; should be changed frequently during a procedure if subject to heavy fluid exposure; and should be changed for each patient. For suspected or confirmed TB/high-risk patients or for protection from true aerosols, a NIOSH-approved (National Insti-tute for Occupational Safety and Health) N95 particulate respirator should be used."

The interest in and demand for surgical masks manufactured in the United States has risen dramatically in the months since SARS (Severe Acute Respiratory Syndrome) has been identified. SARS has infected thousands and killed more than 800 people throughout the world, driving home the importance of infection control and the part that quality face masks play in protecting the population.

What makes a quality face mask and how do you choose? The mask should fit the procedure as well as it fits your face. There are some basic terms you should know before making an educated decision on which face mask is right for you as well as the procedure.

Bacterial Filtration Efficiency (BFE), measures the filtration efficiency of masks using live bacteria (viable particles) that vary in size from 1 to 5 microns. Particle Filtration Efficiency, or PFE, measures the filtration efficiency of a mask using nonliving, or nonviable particles that are fixed in size from 0.1 micron to 1 micron. The higher the PFE, the more protection the wearer has. A face mask relies on microfiber filter media to capture the submicroscopic particle generated by high-speed handpieces, ultrasonic scalers, and lasers. As a point of reference, HIV and TB pathogens are approximately 0.1 micron and 1.0 micron, respectively.

Both the BFE and the PFE of a mask is important. For example, a mask with a BFE rating of 99 percent at 3.0 microns provides less protection than a mask with a PFE of 98 percent at 1.0 micron. Do not be misled by a high BFE/PFE rating without knowing the particle size upon which it is based. Always know the BFE and/or PFE and the associated particle size of the mask you chose. Choosing a mask with a micron particle size of 1.0 or 0.1 should be based on individual preference and the circumstances in which it will be utilized. It is essential to always have several different types of masks available.

Delta P measures the breathability of the mask by differential air pressure on both sides of the mask. The lower the number, the better the breathability; the higher the number, the higher the level of filtration efficiency. This is significant for those with breathing problems such as asthma or emphysema.

In the operatory, fluid-resistance is very important. Fluid-resistant masks resist body fluids and do not permit blood or other potentially infectious materials to reach the skin, nose, mouth, or other mucous membranes under normal conditions. Face masks are available with a fluid-resistant outer layer and tissue layer, as well as with a fluid-resistant outer and inner layer. Always choose the correct mask based on the procedure to maximize protection.

OSHA regulations state, "Masks or masks in combination with goggles, face shields, or glasses with solid side shields ... shall be worn whenever splashes, spray, spatter, or droplets of blood or other potentially infectious materials may be generated, and eye, nose, or mouth contamination can be reasonably anticipated." (Excerpt from Federal Register, Vol. 56, No. 235, Pg. 641277. Dec. 6, 1991. Resistance to Body Fluid Penetra-tion.) Masks should be changed after 20 minutes of heavy exposure to fluid, one hour of normal use, or with each patient. Mask filter media becomes less effective the wetter it becomes.

Discomfort or irritation should not occur when wearing a face mask. If irritation develops, inspect the inside of the mask. If it is colored or has printing, that could be the cause of the irritation. Colors and inks are made from chemicals and dyes which are common irritants. For sensitive skin, the mask of choice would have a white outer layer and a white, non-imprinted interior.

A face mask can only protect if it fits properly. For example, a NIOSH-approved N95 particulate respirator, or high-risk mask, meets the stringent guidelines set by NIOSH for TB exposure control provided that it is properly fit-tested. It is important to note that only NIOSH-approved respirators, imprinted with the word NIOSH on each mask and with the NIOSH symbol also on the box, may be sold as type N95.

Now, you can make a more informed decision about which masks to use. Making the right one will help protect you, your team, your patients, and your practice.

Andrew G. Whitehead is a vice president for Crosstex International, manufacturer of infection-control and disposable products distributed in 60 countries. He has more than 30 years of experience in the dental industry. He is a founding member and serves on the executive board of the Organization for Safety and Asepsis Procedures (OSAP), dentistry's resource for infection control and safety. He may be reached at (631) 582-6777 or by e-mail at [email protected].