Plasma Torch Disinfects Teeth

June 23, 2009 -- The world's smallest plasma torch, a device typically used to rip trash apart at extremely high temperatures, is set to make root canals faster, less painful and reduce the chance of infection.

"Our goal is to guarantee that you won't have to see a doctor for a follow-up visit," said Chunqi Jiang, a professor at University of Southern California who helped adapt plasma torches for dentistry and co-author a recent paper in the June issue of Plasma Processes and Polymers.

"One problem is that between 8 and 10 percent of patients have an infection post-operation. This is intended to eliminate the chance of an infection."

Plasma, or ionized gas, is one of the four basic states of matter, the other three being solid, liquid and gas. Contrary to what we experience on Earth, plasma is by far the most common state of matter in the universe; our sun and other stars are mostly plasma.

Stars create plasma by super-heating atoms and stripping off their electrons. On Earth humans use super-heated plasma to gassify trash, turning last night's leftovers into syn gas.

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The trick to creating plasma at room temperature is by pulsing it. A continuous stream of plasma very quickly heats up the surrounding air. Pulsing the plasma allows the tiny electrons in the plasma to heat up and move around, while keeping the much larger and heavier atom nucleus from heating up.

"If you have a piece of paper with bacteria on it and you apply cold plasma to it, the paper won't burn but the bacteria will die," said Mounir Laroussi, a professor at Old Dominion University who has studied the effect of cold plasmas for years. "Cold plasma can kill bacteria on a variety of surfaces such as teeth or skin."

When plasma is used in the mouth, the free electrons create single atoms of pure oxygen, ozone and other reactive combination of oxygen, all of which search for, and find, other atoms to bind with in the organic biofilms inside decayed teeth.

Biofilms are basically walled colonies of bacteria. In freshwater streams bioflims can be the slippery, brownish gunk on rocks. In the human body bioflims can trigger the onset of an infection and then protect the harmful bacteria from even the most powerful antibiotics.

Atom by atom, the oxygen punches holes in the cell walls and membranes of the bacteria, letting their cytoplasm ooze out and killing the bacteria.