A Dental Infection Control Glossary

The Oxford English Dictionary was first published in 1884, but it took 27 years of terminology compilation before the first edition could even be released. Key to those efforts were the contributions of lexicographical researcher William Chester Minor, MD. A devout bibliophile, Dr Minor spent 2 decades of his life compiling and contributing thousands of definitions to the dictionary’s editors.

Also, Dr Minor did this all from a cell at a high-security psychiatric hospital.

Dr Minor, an American Civil War surgeon, had been found guilty of a murder by reason of insanity. Because he was considered low risk and came to the hospital with a certain air of authority and respect, he was allowed 2 cells: 1 in which he slept, and 1 he turned into a makeshift library. It was from this library that he was able to research and contribute to the fledgling Oxford English Dictionary.

The English language has changed a lot since Dr Minor’s contributions. In the 138 years since the first edition of the dictionary was published, there are some especially relevant terms to highlight, and for our purposes, we look at the infection prevention and control terms that 21st century dental professionals need to know.

Willful Violation.

While most practices can be very conscientious in their infection prevention efforts, regrettably, others may not be so responsible. Practice owners who thumb their nose at prevention efforts may find themselves having to understand OSHA’s “willful violation.”

“It's a violation where the employer knew that a hazardous condition existed but did not make a reasonable effort to eliminate it,” Jonathan Rudin, DDS, MS, MPH, explains. Dr Rudin is a safety and infection control consultant at San Diego Healthcare Compliance. “The fine for a willful or repeated violations is currently $145,027 per violation.”

Cross-contamination

A major consideration for infection prevention and control at the dental practice is avoiding cross-contamination.

“Cross-contamination spreads microbes between persons and/or environmental surfaces, Dr Rudin explains. When addressing cross-contamination concerns, Dr Rudin highlights a number of terms that are thematically related. He references the sixth edition of Infection Control and Management of Hazardous Materials for the Dental Team by Chris Miller.

Clinical Contact Surface

“A clinical contact surface is an area that may be contaminatedwith blood or other potentially infectious material by touching with (gloved) hands during patient care. Such a contaminated surface is a source of pathogens which can ultimately contact other items like hands (again), instruments, and devices,” Dr Rudin says. “Examples of clinical contact surfaces include light handles, light switches, drawer handles, tray table handles, buttons on the tray table, et cetera. Practitioners need to remember that these clinical contact surfaces are rendered contaminated during clinical care and are, therefore, sources of cross-contamination.”

Barriers

Barriers are replaceable plastic coverings that prevent the underlying surfaces from becoming contaminated. Dr Rudin advises that it is required to use barriers that have been made for that specific purpose.

“FDA-cleared barriers are surface covers that have been deemed safe and effective,” Dr Rudin says. “Often practices use the ‘MacGyver’ approach by purchasing plastic film sold as a food wrap. As inventive and potentially effective as these food wraps might be, they are not FDA-cleared for use in a professional healthcare setting.”

Intermediate level disinfectant

Disinfection destroys the pathogens that have the potential to transmit disease. Intermediate level disinfectants are appropriate to accomplish that job.

“After the procedure has been completed, an intermediate level disinfectant should be used to destroy microorganisms on the clinical contact surfaces,” Dr Rudin says. “Remember that such disinfectants do not destroy all microbial life–especially bacterial spores.Intermediate level disinfectants kill vegetative bacteria, most fungi, most viruses, and if so formulated, the tuberculosis-causing pathogen. Be sure to use an Environmental Protectino Agency- (EPA) registered disinfectant deemed safe and effective by the EPA with a tuberculocidal claim on the label.”

Spore testing

Sterilizers must be tested on a regular, periodic basis to ensure that they are, in fact, sterilizing the instruments.

“Spore testing is considered the gold standard for validating the effectiveness of the sterilizer, because it is a biological indicator,” Dr Rudin says. “When a spore test fails, the spores that were supposed to have been destroyed after running through a sterilization cycle remain viable. That's an indicator that the autoclave is not functioning properly.”

Airborne precautions

Infection control and prevention efforts used to fall under 3 headings:

• Standard precautions

• Contact precautions
• Isolation precautions

Standard precautions are a set of infection control practices used to prevent transmission of disease; contact precautions are a set of infection control practices used to mitigate disease transmission via direct or indirect contact with the patient; and isolation precautions didn’t usually apply to dental–they’re more relevant to the medical community where a patient needs to be isolated to receive care.

However, thanks to the SARS-CoV-2 pandemic, there is another form of precautions: Airborne Precautions. Airborne Precautions terms have likely become well known to dental professionals in the last three years, Jackie Dorst, RDH, BS observes. Dorst is an infection prevention consultant and speaker, and she wants to make sure everyone understands key terminology.

“We went through about a year and a half during the pandemic with the scientists and the engineers trying to determine whether this disease is spread by aerosols which are heavier droplets and would fall out of the air more quickly, or if it is an airborne disease with the smaller particle size that would stay suspended in the air,” she says. “And after 2 years, it was determined that yes, COVID-19 is an airborne disease. This is an area of infection prevention that dentistry has not focused on pre-pandemic, even though there are about 16 other diseases that could potentially be transmitted in the air in the dental office, such as influenza, measles, and the rhinovirus (that causes the common cold). We haven't paid a lot of attention to the air quality, and airborne infectious disease transmission is going to be ongoing into the future for both the healthcare community and for the engineering community to deal with it.”

Air Changes per Hour (ACH)

Key to the practice’s airborne precaution efforts is understanding the building’s atmosphere.

“You have to know how the air flow goes through a building,” Dorst says. “And that's where you get into the new term: ACH. That's an indication of how forceful your heating and air conditioning system is in pulling the air through that filter. So right now, if you were in a hospital in a surgery area where you wanted to prevent any risk of contaminating a surgical site with microorganisms in the air, you would want an ACH of at least 15. That's difficult for the heating and air conditioning system to manage in most buildings unless they it is designed as a hospital surgery room. So right now, what we're looking for is to have an ACH in our dental offices that gives us about 6 ACH. So, combining that 6 ACH with a MERV 13 filter gives us the best, optimal filtration of microorganisms in the air for our dental practices at this time.”

Filtration

Keeping the air in the dental practice pure and clean comes down to filtration, and there are a couple of ways to achieve that.

“We had to go to the engineers and ask, ‘How do you manage air that we all have to breathe every day?’” Dorst says. “And if contamination gets in that air, how are you going to remove it and protect the people in that space? There's a lot of research being done by different engineering institutions and educational institutions. Bottom line, the new terms that the dental team needs to add to their infection control glossary is looking at the air in a room. You need to know the cubic feet in your room, multiply the length of the room, the width, and the height to determine how many cubic feet there are in that space that needs to be cleaned. And then that way, you can determine how large your equipment need to be that is filtering that room. And what does your filtration need to be?”

High Efficiency Particulate Air Filter (HEPA)

There are 2 types of filtration most commonly seen in dental practices. The first is HEPA.

“It stands for high efficiency, particulate air filter,” Dorst says. “And a HEPA filter will Remove 99.97% of 0.3 micron-sized particles. That sounds like that's what we want, right? Let's get all of this stuff out of the air. But you have to have equipment so powerful to pull the air through that dense filter that the average heating and air conditioning system would burn up the mechanism. It's just too difficult to pull the air through that dense of a filter to give a HEPA filtration. So, what most commercial buildings like dental offices can manage is that MERV 13 filter.”

Free standing HEPA filtrations units can be used to supplement air filtration in the clinical space.

Minimum Efficiency Rating Value (MERV)

The other filtration method is MERV.

“That stands for minimum efficiency rating value,” Dorst explains. “MERV filters can go from a MERV value of one all the way up to a MERV value of 16. What is recommended by OSHA now for buildings to filter out the small Sars-CoV-2 airborne virus is a MERV 13 filter. A MERV 13 filter will filter out 50% of small particles, down to 0.3 microns.”

High Volume Evacuation (HVE)

Even better than waiting for contaminants to circulate throughout the practice and being filtered out, is to get them right at their origination point.

“There’s 1 more component that's currently recommended by CDC to enhance removing the aerosols that are created by dentist when they're using the ultrasonic scaler, air polisher, air-water syringe and handpiece,” Dorst says. “He or she has to rely on their HVE, and they need to know how strong the HVE is. I've worked in some operatories that had what I call ‘wimpy suction.’ You just didn't adequate suction with either the slow speed suction or the high-volume suction. You didn't get strong evacuation from it.”

It isn't just left to the team members’ subjective assessment as to whether suction devices are strong enough. They can be measured.

“You actually attach a flow meter to the HVE,” Dorst says. “It's a measuring device attached to the HVE. When you turn it on the HVE, it should register at least 300 liters per minute. If you find out that you're not getting that 300, maybe your HVE is only 200 or 150, that's probably the wimpy suction which does not remove the greater amount of generated aerosols.”

N95

Finally, if the pandemic has made anything famous, it’s the humble N95 respirator.

“We've all learned about N95 respirators,” Dorst says. “How to do a seal check when you put on your N95 respirator, such as suck the air in to see if the respirator slightly collapses. If it's collapsing slightly, you've got the proper seal around it. And then you blow air out to see if you can feel any air escaping around the edges. And OSHA requires a Fit Test for each person wearing an N95 respirator which is done with either a sweet or a bitter chemical that you can actually evaluate the correct fit and seal.”

Dr Minor was one of the most prolific contributors to the Oxford English Dictionary in the late 19th century. In the post-pandemic 21st century, there are terms even he couldn’t have anticipated.