In vivo comparison between measurement from two fluorescence-based devices of occlusal and smooth surface caries in primary and permanent teeth

Fluorescence-based devices are adjunct tools for caries detection. Both DIAGNOdent 2095 (LF) and DIAGNOdent 2190 (LF pen) were developed for this application. The purpose of this in vivo study was to compare the relationship between the measurements obtained using the LF and LF pen devices in primary and permanent teeth. The same sample of occlusal and smooth surfaces caries were evaluated by one examiner using both LF and LF pen devices in children. For occlusal caries, measurements were made at 51 sites in primary teeth, and at 83 sites in permanent teeth. For smooth surface caries, measurements were made at 63 sites in primary teeth, and 163 sites in permanent teeth. The values obtained with the LF pen for occlusal caries in primary and permanent teeth (17.6 ± 2.14, 20.6 ± 1.40, respectively) were significantly higher than those obtained with the LF (9.7 ± 1.24, 11.3 ± 0.78). For caries on smooth surfaces, the values obtained with the LF pen for primary and permanent teeth (8.2 ± 1.22, 7.2 ± 0.45) were higher than those obtained with the LF (4.5 ± 0.57, 3.3 ± 0.23). For both occlusal and smooth surface caries, the values were significantly different between the two devices (P < 0.01). The Spearman's correlation coefficients comparing the LF and LF pen values for primary and permanent teeth were Rs = 0.87 and 0.86 for occlusal caries and 0.80 and 0.74 for smooth surface caries, respectively. Values from both devices showed high correlation coefficients, indicating similar principle of function. However, the actual values were significantly different, which indicated that the values obtained with the two devices did not agree. The LF pen should be used with caution in patients for whom the LF is already being used to manage caries.