Influence of professional cleaning and drying of occlusal surfaces on laser fluorescence in vivo

Three dentists recorded laser fluorescence (LF) values on 117 teeth in 70 patients, in the sequence: (1) moist, uncleaned; (2) dried, uncleaned; (3) moist, cleaned; (4) dried, cleaned. LF values varied significantly with surface status (p < 0.01). The optimal cutoffs were up to 5 units lower on uncleaned, moist surfaces compared to the other states. Drying uncleaned surfaces significantly increased LF readings for dentinal caries (p < 0.01). It was concluded that occlusal surfaces should be clean and dry, for precise longitudinal monitoring of caries with LF as well as for detailed visual inspection, which should precede LF measurements.