New preventive tack may relegate drills, pliers to the trash can


Within a decade, the day may come when people will be spared the pain of having bad teeth extracted or cavities drilled. In fact, bad teeth may become a thing of the past.

This rosy prediction is being made by a group of dentists seeking to change the focus of dentistry from cure to prevention.

Masato Kageyama, a dentist in Nakano Ward, Tokyo, has been practicing a treatment called 3DS for the last two years. Short for “dental drug delivery system,” 3DS consists of several steps, the first of which is to analyze a patient’s susceptibility to tooth decay by measuring the level of streptococcus mutans, the principal culprit among bacteria that cause cavities.

The examination of oral bacteria became viable only in the last decade or so, said Kageyama, adding, “it’s something like the blood pressure test physicians give” in that it is a basic and essential exam that should be conducted regularly.

Second, the patient’s plaque is thoroughly removed with tools featuring bristles and rubber, a process that takes up to 90 minutes.

Then the patient wears custom-made retainers — teeth molds made of resin with germ-killing paste inside. At home, the patient puts fluorine gel on the molds and wears them twice a day for about a week, five minutes at a time. A saliva test after this period may show that the amount of s. mutans has decreased to near zero, Kageyama said. If not, the process is repeated. The effect of the 3DS treatment can last about six months.

At Kageyama’s office, only about 10 people have tried this treatment, which is not covered by health insurance and costs somewhere between 75,000 yen and 80,000 yen. But those who have tried are happy with their squeaky clean teeth, Kageyama said.

He stressed that many people do not have to go through all this. Depending on the results of the initial screening, some will be advised to keep their s. mutans level down by improving eating habits, others by removing plaque.

The treatment is effective for pregnant women and mothers raising small children, because children most often receive s. mutans from mothers who share the same spoon when feeding, said Hidenobu Senpuku, a research dentist at the National Institute of Infectious Disease.

Elderly and bed-ridden people who find it physically taxing to take care of their teeth would also benefit from the treatment, Senpuku added.

He has also discovered that hydroxyapatite, a substance commonly contained in toothpaste, is highly effective in absorbing s. mutans.

Doctors practicing 3DS have thus far used pastes containing corsodyl, an s. mutans-killing substance, at their offices. But a safer product has been called for because corsodyl could cause allergic reactions. Home-care products featuring fluorine have been less effective.

Hence hydroxyapatite. Senpuku said he hopes to develop a commercially marketable hydroxyapatite paste in a few years.

But if more people opt for 3DS and fewer people suffer from bad teeth, won’t dentists become obsolete? Senpuku and Kageyama don’t think so.

“The more teeth dentists drill and pull out, the less business they will have, because they will have fewer teeth left to treat,” Senpuku said.

Kageyama agreed: “In the next generation, dentistry will have more to do with checking oral conditions regularly and preventing decay. Patients will find a visit to a dentist’s office less stressful, too.”