By David A. Albert, D.D.S., M.P.H.
Columbia University College of Dental Medicine

You know all about tooth decay, don't you? It's very simple — you get a cavity and the dentist fixes it with a filling.

But today that's not the only way to deal with tooth decay. The dental office visit has profoundly changed. In some cases, your dentist now can fix a decaying tooth without a filling or drilling. It's important for you as a patient to know about these changes so you can obtain the best treatment possible.

The way a cavity forms has not changed over the years. It starts with bacteria called Streptococcus mutans. The bacteria need to be in the mouth for the decay process to begin. These bacteria eat carbohydrates (found in sweets, bread, crackers, pretzels, pasta and many other foods) and produce acid. The acid attacks the hard outer surface of the tooth, the enamel, and removes some of its crystal surface. If enough of the surface is removed and it breaks, then you have a cavity.

But one thing about the decay process has changed — how long it takes. On average, a cavity does not break through the tooth surface until years after the decay process begins. Just a few decades ago, it took only months for a cavity to form.

Dentists no longer approach tooth decay as a rapidly progressing disease. Because the pace is slower, your dentist often can use treatments to stop decay before a cavity develops.

What has slowed down tooth decay? The short answer is "fluoride." Before the 1960s, toothpaste did not have this tooth-strengthening mineral. Now almost all toothpastes contain fluoride. It also is added to most U.S. water supplies. Because of fluoride, teeth are stronger than they used to be and can fight off the loss of minerals in the early decay process. A tooth that repairs itself in this way is stronger and more resistant to future acid attacks.

Tooth decay often gives a warning before it causes an actual cavity. Your dentist may see a white spot on the enamel or a suspicious spot on your X-ray. Timely use of dental treatments, plus your body's natural tooth repair ability, may be able to halt the decay.

This is a less invasive approach to dentistry. The process requires your dentist to evaluate your teeth and mouth and your eating habits. That's how your dentist assesses your risk for cavities. Your treatment will depend upon your risk. Although this sounds simple, it is a new way of thinking for the dental profession.

To assess risk, the dentist will ask questions about your diet, how you take care of your teeth at home, and any history of cavities. You also may get tested for the level of cavity-causing bacteria in your mouth. In this way the dentist can determine if you have a low, moderate or high risk of cavities.

You probably are at low risk of cavities if you have low levels of cavity-causing bacteria in your mouth, don't eat many sweet or starchy snacks, or have not had a cavity in the last year. In this situation, if your dentist sees a suspicious spot on a tooth or on your X-ray, the proper treatment would not be "drilling and filling."

Instead, the dentist could paint fluoride varnish or calcium pastes on the problem tooth. These treatments often can stop or slow down the decay process. They also help the tooth to repair the area where the cavity was forming. This process is known as remineralization.

You may come back to the office more frequently during the next several months. Each time you visit, the dentist will see if the situation is improving and may treat the tooth again. In many cases, the tooth will be repaired without any break in the surface — no cavity. Your tooth will function and a filling may not be needed.

If you are at high risk for dental cavities, your treatment may include therapies such as mouth rinses that are designed to kill bacteria. Sometimes, if you are at high risk, the best treatment may also include placing a filling. In addition, you should visit the dentist more often than average. The dentist will check to make sure that you are not developing new cavities and will give you preventive treatments such as fluoride.

This is the modern approach to dental therapy — an assessment of your risk, followed by treatment based on that assessment. You should request it at your next dental visit.

David A. Albert, D.D.S., M.P.H., is an associate professor and associate director of community health at the Columbia University College of Dental Medicine. He also holds an appointment in the Joseph Mailman School of Public Health at Columbia University. He maintains a practice within the ambulatory care network of the Columbia DentCare program in the community of Washington Heights/Inwood in Northern Manhattan.