Cold-Plasma Jets for Root Canals

”We are specifically targeting biofilm because those are the most resistant causes of infection,” says Jiang, whose device destroyed biofilms 99.99 percent of the time in experiments conducted in petri dishes. Jiang says that a dental company has shown interest in her cold-plasma jet.

At Huazhong University, in China, Xinpei Lu is working on a prototype device that actually generates the plasma plume inside the root canal. He is working with a Chinese company to bring the technology to market.

”When a patient needs to have root canal treatment, he or she needs to visit the dentist office at least two times,” Lu says. ”With our device, a patient only needs to visit the dentist’s office one time. Besides, there is no painful sensation. The patient only feels gas blowing.”

Although both devices show promise, Lu and Jiang say that more work lies ahead. Jiang says that the U.S. Food and Drug Administration will need to test the safety of the gases generated by her plasma jet. Lu, whose device was tested against one of the main types of bacteria that necessitate repeat root canals, wants to run experiments with other bacteria.

”It’s not a magic bullet that kills everything,” says Mounir Laroussi, one of the pioneers of the study of cold plasma in the United States and director of the Laser and Plasma Engineering Institute, at Old Dominion University, in Norfolk, Va.

Experiments conducted at Laroussi’s laboratory have found that cold plasma cannot kill bacteria that has developed endospores—a tough layer of protection that forms inside the cells of some types of bacteria. Yet Laroussi says his own device, called a plasma pencil, has shown good results against various types of oral bacteria in lab tests conducted at ODU’s dental school.

Lu and Jiang say that if clinical trials are successful, their devices could hit dentists’ offices by 2012.