Cologne/Bonn – The dentist suspects a case of caries, yet he cannot find any evidence of it with his mirror, probe or x-ray device. Not surprisingly, this is called hidden caries.
Conventional dental treatment is generally powerless against it. But now a semi-conductor laser can penetrate the upper layer of tooth and show up the affected area.
Dental practices already use many different types of laser, including this one to tackle caries, a widespread disease. The Institute of German Dentists (IDZ), based in Cologne, says 99.2 percent of German adults suffer from some form of caries, or have already lost one tooth or more as a result of decay.
But Professor Matthias Frentzen of the Bonn University Dental Hospital maintains that lasers are not always the correct way to treat caries. If caries is discovered in its early stages, a heat laser could be an effective way to treat it.
The laser heats the enamel on the outer layer of the tooth, thereby killing the bacteria in its cracks and fissures and sealing up breakage on the flat top of it. “Yet little attention has so far been paid to possible side effects, such as the laser’s effect on the nerve of the tooth,” warned Frentzen. He advises the continued use of conventional fillings.
Caries is largely caused by bacteria that are attracted to acids. They feed on the sugar and other carbohydrates in food remains, and this ferments on teeth within minutes. The resulting acids dissolve minerals in the tooth enamel and cause holes. The earliest tooth damage usually shows up on the furrows of the tooth’s flat surfaces. If this acid attack is not stopped, caries will soon also destroy the dentine, the yellowish tissue that makes up the bulk of the tooth, and dental pulp further below it. Eventually it can cause a tooth to fall out.
When caries reaches an advanced stage and is already attacking the dentine, dentists must find a way to reach the affected area. They usually do this with a drill. Only one per cent of German dentists have invested in a laser, which would offer a less painful alternative.
They are hesitant for two reasons. First, laser medicine is advancing so quickly that the hardware could quickly become outdated. Secondly, lasers are between five and 10 times slower than a conventional drill.
Lasers could, however, offer a painless alternative in the future, particularly for people with a fear of the dentist. Laser treatment gives patients only a slight sensation of pins and needles.
Chemical treatment is another relatively painless way of removing caries, although it does involve a small amount of drilling to reach the affected area. After that, a gel is applied which loosens the infected dentine. Further drilling is needed to prepare the hole for filling. This treatment is also generally rejected because it is time consuming.
Amalgam, an alloy of mercury and various metals, remains the most common filling material. It has a bad reputation because, ever since it was introduced 130 years ago, there have been questions over whether the body can tolerate it. Mercury, which is poisonous, can be released into the body, usually when a filling is replaced. But the German General Dental Council (BAZEK) claims amalgam is better than its reputation. Partly because of all the misgivings, it is the best researched dental material.
A laser cannot be used to replace amalgam because the heat it generates releases mercury. One alternative to amalgam is a plastic filling, which is especially effective for smaller fillings. But patients usually have to pay the extra cost of them.
The future of caries treatment could lie simply in prevention rather than expensive equipment. Many dental clinics already offer information about nutrition and dental care to ward off the bacteria.
The mineral fluoride also has a special place in caries prevention. The German Society for Dental and Oral Medicine (DGZMK), based in Duesseldorf, recommends using fluoride toothpaste and salt with added fluoride to protect the teeth.
