Suction Significantly Reduces Aerosol Risks in Open Clinic Settings

Dentistry Today
Photo courtesy of The Journal of Dentistry


Photo courtesy of The Journal of Dentistry

Suction substantially decreases contamination in open clinic settings, according to Newcastle University, which has been studying how to mitigate the risks of dental aerosols. According to the university, its findings have been used by the Dental Schools’ Council, the Association of Dental Hospitals, and the Scottish Dental Clinical Effectiveness Programme to guide COVID-19 dental policies.

Aerosol-generating procedures (AGPs) such as fillings and root canal treatment can spray aerosol and saliva particles from dental instruments large distances, but contamination varies widely depending on the processes used, the researchers said.

In open clinic settings, dental suction substantially decreased contamination at sites far away from the patient, such as bays 5 meters away. Often, these distant sites had no contamination present, or if contamination was detected, it was at very low levels, diluted by 60,000 to 70,000 times. Also, after 10 minutes, very little additional contaminated aerosols settled onto surfaces, making it a suitable time to clean an operatory after an AGP.

“Our research has improved our understanding of dental aerosol-generating procedures and identified how cross-contamination could be a risk for spreading COVID-19,” said Dr. Richard Holiday, NIHR Clinical Lecturer in Restorative Dentistry.

“When the pandemic began, dental services were significantly reduced, and there was an urgent need by the profession to focus on how dental clinics could work in a safe environment for patients and staff,” Holiday said.

“We now have a much greater understanding of where the splatter of aerosols go and how far they travel during different procedures and settings, allowing clinical teams to make informed decisions to protect people,” he continued.

“I am pleased that our research here at Newcastle has been used nationally by leading dental bodies to inform their policies on how the profession should carry out procedures during the pandemic,” Holiday said.

Researchers from the School of Dental Sciences including clinicians, dental nurses, microbiologists, and scientists carried out the study. They used fluorescein tracer dye while carrying out AGPs on a dental mannequin to analyze how far and where aerosol particles and saliva traveled from the patient’s mouth.

The researchers performed a range of procedures and analyzed the effects of suction and ventilation. They also looked at contamination up close and in an open-plan clinic. 

“For the safe reopening of dental services, it was essential to understand the behavior of the aerosols that come out of a patient’s mouth during dental work,” said Kimberley Pickering, a research dental nurse involved in the study.

“We now better understand where the aerosols go and how far they travel during different procedures and settings,” Pickering said. “We also understand how dental aerosols settle over time, which has helped inform cross-infection control purposes.”

Further research will continue to focus on where aerosol and droplets from dental instruments travel and how far they go. Experts will also look at how long aerosols hang around in the air and examine a number of common dental procedures and methods of controlling aerosols.

The research also will investigate if viruses can be carried in dental aerosols and if they remain infective at a distance from the procedure, which will help experts understand how to reduce the risk of viruses like SARS-CoV-2 being spread by aerosols during dental treatment.

The study led the researchers to develop a new clinic configuration to allow the safe return of dental students and their patients. The School of Dental Sciences is one of the first institutions in the United Kingdom to recommence teaching AGPs to students in person.

“Being a dental student during the pandemic has been a big challenge, but dental students feel lucky to come into university every day and get in-person teaching as it’s a privilege to treat our patients,” said fourth-year dental student Paddy Crenshaw.

“The dental school has been very supportive since the pandemic began. It is clear that senior clinicians and academics have worked hard behind the scenes to allow us to return to clinical teaching,” Crenshaw said.

“The common goal of delivering first-class treatment for our patients has enhanced the dental school’s sense of community, and this has really helped me through this term,” he said.

“I am proud of the way Newcastle Dental School and all of its staff and students have come together in the face of adversity through the COVID-19 pandemic. To know we are one of the first schools in the country offering a full range of student-led treatments for our patients makes me feel lucky to be studying here,” Crenshaw said.

“Due to the extensive research undertaken by the school, I have never felt unsafe, whether extracting a tooth or doing a simple examination, I know the school’s protocols are allowing me to work safely,” he said.

The study, “Evaluating Contaminated Dental Aerosol and Splatter in an Open Plan Clinic Environment: Implications for the COVID-19 Pandemic,” was published by The Journal of Dentistry.

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