Early Identification of Carious Lesions, Comparing DIAGNOdent and Caries ID

Objectives: DIAGNOdent (KaVo Dental Corp.) and Midwest Caries ID (DENTSPLY Midwest) are marketed for use in identification of occlusal incipient lesions. This study assessed the ability of these two systems to identify in vitro bacterially produced early lesions in enamel as verified with hardness testing and optical microscopy.

Methods: The root apices were sealed on extracted molars and the tooth surfaces painted with nail polish leaving a 3x3mm occlusal window. Initial readings were taken using DIAGNOdent classic system and Midwest Caries ID. Molars were then placed in test tubes containing 3% Sucrose BHI media inoculated with S. mutans. At 2, 4, 6 and 7 weeks, ten teeth were removed, sectioned by a diamond saw and ground to 200mm thickness using a drum sander (1200 & 4000 grit SiC paper). Knoop microhardness and polarized light measurements were taken past the deepest point of the induced lesions.

Results: Visible identification of demineralization was notable at two weeks. DIAGNOdent identified lesions at two weeks with 9% and 19% of enamel affected per microhardness and polarized light, respectively (Figure 1). Caries ID definitively identified lesions at six weeks with lesions extending 12% and 23% of enamel depth per microhardness and polarized light, respectively. There was excellent correlation (R²=0.95) between microhardness and polarized light measurements. DIAGNOdent showed a slightly better correlation than Caries ID in changes of measured values over time and lesion depth by KHN (R²=0.94 and 0.80, respectively; Figure 2), and similar correlation with polarized light (R² =0.80).

Conclusions: DIAGNOdent and Midwest Caries ID were able to identify incipient lesions by detecting their progression with increasing values over time. The two systems were unable to be compared due to differing data collection styles; however both devices accurately recognized lesions confined within the first one third of the enamel depth.