Correlation between laser fluorescence readings and volume of tooth preparation in incipient occlusal caries in vitro.

OBJECTIVE This study evaluated the correlation between laser fluorescence readings and the extent of incipient occlusal caries as measured by the volume of tooth preparation in vitro. MATERIALS AND METHODS One hundred and three permanent molars and premolars containing incipient occlusal pit-and-fissure caries and sound occlusal surfaces (1/4 of the sample, control) were selected. DIAGNOdent (KaVo Dental Corporation, Lake Zurich, IL, USA) readings were obtained according to manufacturer instructions. Caries was removed with 1/4 round burs in high speed. The volume of tooth preparation was measured using a surrogate measure based on the amount of composite needed to fill the preparations. Sensitivity and specificity using different cutoff values were calculated for lesions/preparations extending into dentin. The results were analyzed statistically. RESULTS The Pearson correlation for preparation volume and DIAGNOdent reading measurements was low (r = 0.285). Sensitivity and specificity of DIAGNOdent for detection of dentinal lesions were 0.83 and 0.60, and 0.66 and 0.73 for the cutoff values of 20 and 30, respectively. CONCLUSIONS Within the limitations of this study, laser fluorescence measured with DIAGNOdent does not correlate well with extent of carious tooth structure in incipient occlusal caries. CLINICAL SIGNIFICANCE Clinicians should not rely only on DIAGNOdent readings to determine the extension of incipient occlusal caries.