Tooth Decay Detected by Laser and Light Systems

[Buster's Uncle]

Tooth Decay Detected by Laser and Light Systems
Devices Find Signs of Decay Earlier Than X-Rays, but There’s a Risk of False Positives
The Wall Street Journal
By Laura Johannes  Jan. 5, 2015 1:38 p.m. ET



With the Canary System, light and heat are reflected off of a tooth to detect changes in the tooth’s structure.  Quantum Dental Technologies Inc. 



The Claim: Laser and light machines can detect tooth decay earlier than X-rays, which dentists say generally don’t show the presence of cavities until there is a fairly large hole in the tooth.

The Verdict: A growing body of research shows the light-based devices are highly sensitive. A recent study found one device caught 93% of early caries, the dental term for tooth decay, compared with 27% for X-rays. But some scientists warn the machines could result in overtreatment—as early decay may not need a filling.

The $14,000 Canary System, named after the birds used by coal miners for early detection of dangerous gases in mines, hit the U.S. market in 2013 from Toronto’s Quantum Dental Technologies Inc. It is one of the newer models in a class of so-called cavity-detection systems designed to give early warning of decay. The Canary gives out readings on a scale of up to 100, with a reading over 20 indicating signs of tooth decay; over 70 indicates advanced decay. So far, insurance coverage is scant, so many dentists are offering the scans free of charge as part of a regular office visit or cleaning.

In her Salem, Mass., office, dentist Pamela M. Maragliano-Muniz demonstrated her Canary System for me. She put safety glasses on a staff member and shined a red light on each tooth for a few seconds. The first scan, which is displayed on her computer monitor, came up with a reading of 12, suggesting a healthy tooth. But another tooth showed a 93, suggesting an advanced problem.



The $14,000 Canary System from Quantum Dental Technologies Inc.  Quantum Dental Technologies Inc.


Earlier light systems measured the fluorescence caused by bacteria that cause tooth decay. The Canary uses heat and light reflected from the tooth to warn of changes in the structure of the tooth. Some devices offer other advanced new features. The Spectra Caries Detection Aid from Air Techniques Inc. in Melville, N.Y., can automatically integrate the results into patient records, the company says.

The Canary, unlike earlier cavity detectors on the market, can also catch decay between teeth, says Stephen Abrams, president and founder of Quantum.

A study of the Canary used between teeth—presented in July at the European Organization for Caries Research meeting in Greifswald, Germany—tested 50 extracted teeth in the lab using both X-rays and the Canary. The researchers then examined slivers of the teeth under a microscope to look for decay. The Canary caught 93% of the decayed teeth but also incorrectly gave a positive result in seven healthy teeth. X-rays detected 27% of the decay and gave a false positive result in five teeth.

Since it is easier to maneuver the Canary in a lab setting, the results are likely better than would be seen in a human study, says co-author Bennett T. Amaechi, a professor at the University of Texas Health Science Center at San Antonio’s School of Dentistry.

The devices do a good job of detecting decay in extracted teeth tested in a lab, scientists say. But there aren’t enough studies on their use in humans—particularly on how to use the results to whether to drill or not, they say.

“The jury is out, and not on the question of does [the technology] work, because it does,” says Matthew Messina, a Cleveland dentist and spokesman for the American Dental Association. “The question rests at what point do we intervene?”

The existence of false positives shows it’s important to use a variety of examination methods, including X-rays and visual exam, before drilling, says Dr. Amaechi.

When a machine finds early decay, before agreeing to go under the drill, patients should ask the dentist if the tooth decay can be reversed, says Clifton M. Carey, a professor at University of Colorado School of Dental Medicine at Anschutz Medical Campus in Aurora, Colo. Methods to reverse decay include better toothbrushing, improved diet and a potpourri of toothpastes and gels that add fluoride and minerals to the teeth, dentists say.

Dr. Carey, who has no financial ties to any of the device companies, found in a 2013 study that the Canary can give early warnings of new decay under a composite, or white-colored, filling.


http://www.wsj.com/articles/tooth-decay-detected-by-laser-and-light-systems-1420483113?ru=yahoo?mod=yahoo_itp