Detection of occlusal caries under sealants by use of a laser fluorescence system.

OBJECTIVE In recent years, various dental caries diagnosis systems, including digital radiography, light fluorescence, and lasers, have been developed. The aim of this study was to evaluate the new laser fluorescence system known as DIAGNOdent for its ability to detect occlusal caries under sealants. BACKGROUND DATA Fluorescence induced by laser light for early diagnosis of enamel caries was introduced by Bjelkhagen et al. in 1982, but these systems were difficult to use in the oral cavity. Recently, DIAGNOdent has been shown to have a higher diagnostic validity for the detection and quantification of caries lesions than the electronic caries monitor and to have a higher reproducibility for measurements, according to work by Lussi et al. in 1999. The laser diagnosis system is able to indicate the value of reflected fluorescence on a digital display. This value is associated with the carious progression. METHODS Thirty-two extracted permanent premolars and molars that had occlusal dental caries were used in this study. The reflected fluorescence was measured by use of DIAGNOdent at the occlusal surface of the tooth before and after chemical irrigation, acid etching, and application of a light-cured fluoride releasing sealant. The measurements were two or three points per experimental tooth. A total of 53 points on the experimental teeth was evaluated. RESULTS The mean reflected fluorescence value was significantly decreased by chemical irrigation; however, no difference was noted between the value before and the salve after acid etching. These teeth were divided into three groups: clear, red, and white as tooth color sealants of the tooth. The reflected fluorescence value before and after sealants was tested for statistical significance. The diagnosis of caries under sealants was up to 10 of reflected fluorescence value in the study. Clear and red sealants were used to reveal caries under sealants using visual inspection, and all sealants groups achieved 90% of reflected fluorescence value after sealants application. However, the white sealants did not reveal caries through visual inspection. The detection ability of caries under white sealants was 53.5% (n = 23/42). CONCLUSIONS This laser diagnosis system makes it easy to detect the existence of caries under a pit and fissure sealant during a routine check-up.