Dentists Beam in on Cavities

Posted by Dr. Edward Magida | Filed under , , , ,

Captains log, stardate 2002: We're rounding Alpha Caninigus and heading towards a rendezvous with Starship Incisorus. The reason? We recently acquired a new instrument, one whose origin seems right out of science fiction.

Its name is the Diagnodent and when I use it I feel like the doctor on Star Trek. Remember how he could diagnose a problem by passing a wand-like instrument over a person? Diagnodent is a new technology that can help diagnose dental cavities in a similar way.

One time-honored way to detect dental decay in teeth has been to stick a sharp dental explorer into the nooks and crannies on the chewing surfaces of a person's teeth. If there was a 'stick", meaning the explorer got wedged inside one of the tiny grooves of the tooth, this was considered a cavity and the tooth needed a filling. In addition, the dentist took x-rays to help look for the classic signs of decay, which are dark shadows on the films. Between x-rays and poking around with the explorer, most cavities were found.

There are several problems that can make cavity detection difficult. Fluoridation, which has been shown to help prevent cavities by "hardening" the enamel of teeth, is not 100 percent perfect. It has, in some circumstances, made the detection of small, subsurface cavities difficult, because the 'hardened" enamel remains intact, but the subsurface decay develops through tiny fissures and microcracks. The decay hidden beneath the surface is inaccessible to probing with the dental explorer. To further make things difficult, x-ray diagnosis of early has been shown to be inaccurate if the decay has not developed to a certain depth.
This is not good since the best time to treat a cavity is when it is small so that it has not destroyed much tooth structure and has not come close to the nerve of the tooth. By the time some cavities can be detected, a significant amount of tooth structure is lost and sometimes the nerve has been affected.

Beam me up, Scotty... well almost. The Diagnodent uses a laser beam that measures changes in fluorescence levels within tooth structure to quantify decay progression. When the laser shine onto an area of decay, even if that area is not detected on an x-ray or with the tip of an explorer, it will register that decay is present. The dentist can remove the small cavity and place a very conservative filling in the tooth. Conservative is the name of the game, since you want to find and treat cavities as soon as they develop.