There are a number of different modalities for detecting caries. The most popular devices detect caries through the use of fluorescence. Normal healthy tooth structure produces little or no fluorescence. Carious tooth structure will fluoresce proportionate to the degree of caries. These devices are highly sensitive to caries but have a low specificity. This low specificity means that these devices will measure the fluorescence of anything. Caries detection devices are another tool aiding in the diagnosing of caries along with conventional diagnostic tools and good professional judgement. They can be used to monitor the progression of caries and aid the decision of prevent, remineralize or restore.
The most popular device is the KaVo DIAGNOdent. The DIAGNOdent is a 655nm laser (the same as a red laser pointer) that detects fluorescence of decay in teeth. The DIAGNOdent will produce a value that can assist in the diagnosis of caries.
The DIAGNOdent emits an increasing audio tone and digital readout indicating the amount of caries present. The numbers can be recorded for real world “Watch” or to determine if remineralization is taking place. The DIAGNOdent is approved for use on smooth surfaces and pits and fissures only. It is not approved for interproximal use.
A similar device is the Midwest Caries LD. Instead of a laser it uses a light enmtting diode (LED) to measure the caries reflection signature. The major difference is, instead of a numerical readout, the CAries LD. has a red and green indicator light for caries. This makes monitoring any progression of caries of remineralization more difficult. The device also beeps – the faster the beep the more decay present. The caries I.D is approved for smooth surfaces, pits and fissures, and interproximal surfaces.