Pandemic inspires dental safety research and innovation at MUSC

March 04, 2021
Dr. Walter Renne holds lip retraction device he created.
Dr. Walter Renne holds a lip retraction device he created with a 3D printer at MUSC. Photo by Sarah Pack

Dentists, once labeled the workers who face the greatest coronavirus risk, have important new information about how to protect themselves and their patients, thanks to research and innovation at the Medical University of South Carolina.

Walter Renne, a dentist who serves as a professor in the James B. Edwards College of Dental Medicine, led a team in testing how well several devices work when it comes to preventing saliva from getting into the air during dental procedures. It was an underresearched area. Along the way, he invented a new device that goes on the market this spring.

“In the dental space, as we work on our patients, oftentimes we generate aerosols, whether you're running a handpiece, such as the dental drill, or if you're using special ultrasonic scalers for cleaning teeth, nearly everything that we do generates this plume of microscopic particles that are dispersed out into the air,” Renne said.

“In light of COVID-19 and other respiratory infections that spread via aerosol droplets, we were concerned about ways to mitigate that to keep those aerosols from escaping the patient's mouth during routine dental procedures.”

So Renne, who has extensive research experience and holds several patents for dental inventions, got to work. “We started early on with kind of a research project, just trying to see what items exist on the market already and how well are they doing at mitigating aerosols. We tested a bunch of different products,” he said. 

That study was exploratory and didn’t try to simulate real-life conditions. But it did give the MUSC researchers a foundation for a more scientifically sound study they hoped would finally give fellow dentists data to show what works and what doesn’t. 

Diagram of lip retraction device created by Dr. Walter Renne. 
Renee's device is designed to connect with a high volume evacuator to boost its performance. Image courtesy of Dr. Walter Renne

Meanwhile, Renne got creative. Using a 3D printer at MUSC’s dental school, he built something new: a special lip retraction device designed to hook up to the dental high-volume suction unit dentists use to suck saliva from patients’ mouths during procedures. 

“The nice thing about this device is that it's hands-free. So it hooks up to the patient without having the need for somebody to hold it,” Renne said.

He and several colleagues put it to the test, along with some other devices already on the market, in a study they later wrote about in the Journal of Esthetic and Restorative Dentistry. The research was funded by the South Carolina Clinical & Translational Research Institute, which is based at MUSC.

They found that when they used dry-field isolation methods – ways of keeping the area of the mouth a dentist is working on dry – along with high-volume evacuators to suction saliva, they were able to reduce dramatically the amount of spit in the air and on the dentist’s face shield.

Researcher and dentist John Comisi is an associate professor in the College of Dental Medicine.“We found that when you use many of these things in tandem with high-volume evacuators, you can mitigate things 100% – or pretty darn close.” 

Renne’s device stood out, Comisi said. “The patented device Wally created is extraordinarily effective. He had a unique way of looking at things.”

His device can also be made inexpensively, costing around $5, Comisi said. The CAO Group, which sells high-tech dental products and makes one of the devices included in the MUSC research that also did well, picked up Renne’s device for licensing.

Renne said he’s pleased to give dentists another option as they try to work safely during the pandemic and beyond. “It's not a magic bullet that's going to eliminate all aerosols, but it's definitely going to make the operating space safer.

And knowing that his team’s research finally gives the field better data on safety when it comes to not only his invention but several other devices already in dentists’ offices is rewarding. 

“We use the universal precautions of course, and we've been doing a good job at mitigating aerosols. It just hasn't been 100% in the past.”

About the Author

Helen Adams

Keywords: COVID-19, Research