Some people have called it dentistry's dirty little secret, one that the American Dental Association has known about for years.
CBS News This Morning Co-Anchor Julie Chen reports the bacteria that grows on dental water lines could make you sick.
You know the routine: First come the rubber gloves, mask, goggles, sterile instruments and then open wide for a spray of dirty water.
Dirty water refers to the bacteria growing on biofilm, that slimy stuff in most pipes and tubing.
In dentists' offices, the drill sprays and other special instruments only need a small amount of water at a time, so the rest sit long enough in the small tubing to let bacteria breed. With every blast of water, you could get a mouthful.
"Dental patients should be very concerned, because the water doesn't meet the basic standards that we are used to in our country," says Margaret Johnston, a dentist fighting for education and legislation on dental water.
She points out in her published research that most dental water has more bacteria than pond water.
"What we found is the water in the majority of dental offices is substantially contaminated and [of] a very poor quality - not drinking water at all," she says.
And Johnston's conclusions aren't anything new. For almost 30 years dentistry journals and magazines have been filled with research warning about the high bacteria levels in dental water.
But it wasn't until a California dentist died in 1993 of the same strain found in his dental lines that the dental industry began to rally around the issue.
"Many patients don't realize that they have been injured in the dentist office. They just chalk it up to just a freak of nature rather than originating in the dentist office," Edwin Zinman says.
Zinman, a San Francisco attorney and dentist, believes that the reason why there aren't more reports of people getting sick is because doctors don't make the connection.
He has settled two cases in which bacteria in the dental lines were found to be the same bacteria making the patients sick.
"There is no doubt that the infection came from [the] contaminated dental water unit into the patient's mouth, into their bloodstream," he says. "Seriously injuring the patient."
Bee Forman was one of Zinman's clients. In 1987 she went for a routine dental cleaning, and two weeks later she had a seizure. Her husband Bill Forman rushed her to the hospital where they found a brain abscess.
Bee Forman lost basic motor skills and some of her memory. When her doctor tested the water in her dentist office and compared it with the bacteria in her brain abscess, he got a match.
"When they examined the poison in my brain, I think they knew," says Bee Forman.
She received a settlement from her dentist but the condition of her settlement doesn't allow her to reveal who her dentist was.
"It happened to us. I'm sur it is happening to other people," adds her husband.
"There has been no indication from the Centers for Disease Control and Prevention that dental unit water is causing any kind of public health threat," says Dr. Chris Miller.
A spokesman for the American Dental Association, Miller agrees that dental water bacteria are high, but he says that the ADA is taking steps to fix the problem.
It has issued voluntary water standards and is trying to get dentists to focus on the issue.
"The American Dental Association provides educational materials in this area," he says. "The dentist[s] look at this information and they decide what would be best for their own practices."
But he is quick to point out that most people don't have to worry about the problem. "Healthy people are not as susceptible to organisms in the environment as those who may be immunocompromised, because they have a certain systemic disease or weakened body."
But critics say that for high-risk patients such as seniors, asthma sufferers, people with weak immune systems, the American Dental Association isn't doing enough to combat the problem.
For more information visit the American Dental Association Web site or The Coalition for Safe Dental WaterWeb site.
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