Fluorine content in dental tissues has been measured by using nuclear reactions with high energy proton beams and detecting alpha particles and/or gamma rays emitted from fluorine nuclei. The sensitivity of the nuclear analysis reaches 0.1 mg/g and the depth distribution of fluorine atoms can be determined up to 5 mum. The depth resolution is about 0.3 mum with alpha particles and 0.1 mum with gamma rays. Distributions of fluorine both in surface enamel and in cross section of teeth were measured by using a proton probe 500 mum in diameter. A systematic increase in the fluorine concentration has been observed in the healthy incisors dental enamel (1-3 mg/g) with respect to the molar ones (0.5-1 mg/g). A comparison between the fluorine content in healthy teeth and in pathological ones was made.