image: Communications Plus Digital

Nervous about getting your teeth cleaned or a cavity filled? Cringe at the buzz of a dentist’s drill? Relief may soon be on the way.

While laser dentistry has been around for a few years, it has not yet become widespread for economic and technological reasons. But thanks to researchers at NASA—studying, of all things, ways to make air travel safer—your next trip to the dentist may be virtually painless.

From wind shear detection to dental surgery

Surgical lasers are far more precise than a hand-held drill or scalpel, so they would undoubtedly improve dental procedures by allowing dentists to conserve as much of the original, healthy teeth and gums as possible, and also by eliminating pain by up to 95 percent. But while conventional laser surgery has been successfully employed for over two decades, dentistry has been slower to adopt lasers for surgery.

Lasers perform surgery by heating the water in the body’s cells to boiling within microseconds. The boiling water explodes the cells; many cells bursting simultaneously ablates tissue layers just like a surgeon’s scalpel slices away body tissue. The problem for dentistry is that different wavelengths are used on different body tissues. "A two Micron line [is] used for soft tissues [such as gums], and the three Micron wavelength interacts with hard tissue [like teeth and bone] very well," says Keith Murray, a physicist and aerospace technology researcher at NASA’s Langley Research Center. Since dentists treat both soft and hard tissues, they need two different wavelengths, which means two laser units, which means more of an investment of money and technical training. Today, two single-frequency dental lasers cost about $63,000, and only five percent of the nation’s 140,000 dentists use them.

A solution to this problem was discovered when Murray and his team at Langley were searching for more effective ways to detect wind shear. (This atmospheric condition is extremely hazardous, as it can slam airliners into the ground.) The Langley researchers were using lasers to detect naturally-occuring aerosols that are used to measure air movements. "Out of that research, we sort of stumbled across an effect that we could generate these two different widely separated wavelengths," says Murray. "It became evident that you could use that for other applications," like dentistry.

Two lasers in one

Normally a laser cavity, the heart of any laser, can only generate one wavelength. The wavelength, or frequency, gives each laser its unique ability to slice, bore holes, or detect air currents. Murray and Norman Barnes of Langley, and Ralph Hutcheson of Scientific Materials Corporation in Bozeman, Montana, devised a new technique that generates two laser wavelengths from one device, thus eliminating the need for more hardware. NASA estimates that the dual wavelength unit will set your dentist back only about $35,000.

Another advantage of NASA’s new technology is that non-physicists can operate the dual-frequency feature of the laser by simply pushing a button instead of manipulating the internal laser components or operating hardware (the two cavities), difficult operations even for skilled laser technicians. "No dentist wants to be a laser scientist," Murray says. "It’s in their best interest to be able to use something that’s easy."

When will it come to my dentist office?

Several companies, including Premier Laser Systems, Biolase and Continuum Biomedical, manufacture single-laser dental units. Lantis Laser, a new dental technology firm in New Jersey, learned of the new technology and formed an agreement with NASA to develop the new lasers for commercial use in dental surgery. NASA and Lantis expect to win Food and Drug Administration (FDA) approval of the new dental surgery lasers in mid-2001, and hope to begin commercial sales by the end of that year.

This could mean the end of huge needles and the slobbering from the anaesthetized side of your mouth after dental work. Laser dentistry will also eliminate (or at least replace) that ominous sound that grates in your skull when the dentist operates a drill, another cause of anguish in dental patients. Murray hopes this means that more people will visit dentists more often: "It would do humanity a lot of good."

He also says dentists look forward to using the new equipment. "I spoke with a dentist who told me, ’If you can come up with an instrument that would allow me to work on a three year old without him going home with this absolute look of terror on his face, I would be more than happy to use it.’"

Elsewhere on the web:

American Dental Association

"NASA Success Story--Multiwavelength Laser--More People Will Experience Painless Laser Dentistry Because of NASA Technology"

American Society for Laser Medicine and Surgery

"FDA OKs lasers for children, hard tissues" from ADA News

NASA Langley Aviation Safety Center Home Page