Laser Cavity Detection

How does your dentist know when you have a cavity? Traditionally, this is accomplished in two ways: First, there is visual inspection. Here we look and poke at three of the five tooth surfaces: the biting surface, the cheek side and the tongue side. We look for discoloration and breaches in the integrity of the normally hard enamel and root surfaces. Next there is an examination of the interproximal, or in-between surfaces, via x-ray imaging. These two methods are probably 95% effective. Yet despite the combination of clinical and radiographic examinations enhancing our ability to discover most decay; believe it or not, the number one (dental) public health advancement of the twentieth century, fluoride, on occasion inhibits our ability to detect decay in the pits and fissures of the biting surfaces. With so much fluoride in toothpastes, mouth rinses, vitamin supplements, and public drinking water, we have produced generations with very hard enamel surfaces that are more resistant to breakdown than those of previous generations. This is generally very good, but occasionally presents a diagnostic challenge. Although seemingly hard, and resistant to physical probing, bacterial invasion of the biting surface pits and fissures can penetrate below the enamel layer, well into the dentin layer, before becoming obvious on clinical or radiographic examination. In the past the discovery of such problems would occur only after the underlying support of the enamel failed and this surface collapsed, there was enough decay to become obvious on an x-ray, or the tooth became sensitive or painful. Faced with this problem, dentists had to make a choice: either engage in wholesale cavity preparations on the biting surfaces to detect this problem before it got worse, or try to guess which teeth were at risk. One choice could lead to over-treatment, the other to under-treatment.

To deal with this issue our practice uses a third method of decay diagnosis: "laser-assisted" decay detection. The tool that we use is called "DIAGNOdent." DIAGNOdent is a small desktop device with pencil-sized wand that emits a laser beam. This laser does not cut or alter tissue, but rather the beam is directed into the tooth, penetrating through enamel and, to some degree decay/dentin. The sophisticated computer technology contained within the unit is programmed to analyze the degree of light penetration and dispersion, thus differentiating healthy from diseased tooth structure. This brilliant technology is not only highly accurate in disease detection, but is also helpful in quantifying the degree of breakdown. This is helpful in knowing prior to the start of treatment in order to know how much intervention will be needed.