The determination of urinary fluoride/creatinine ratio (Q) in monitoring fluoride intake.

Linear correlation (r = 0.6811, p less than 0.001) was found between the 24 hour urinary excreted fluoride quantity and fluoride/creatinine ratio (Q) of the morning urine sample of 21 school children living in a children's home in Hungary. The mean value of fluoride/creatinine ratio (Q) in groups of children from eight different parts of Hungary, also showed linear correlation (r = 0.9720, p less than 0.001) with the measured fluoride concentration of drinking water. The urinary fluoride/creatinine ratio (Q) seems sufficiently informative for controlling fluoride intake in the course of caries preventive field studies.