Title: Application of fluoride electrode to analysis of environmental and biological samples (F Series No. 14)
Abstract: In order to compare the effectiveness of several topical fluoride application procedures, the enamel biopsy was applied to determine the removed fluoride and calcium by acid etching. The biopsy was carried out with the following technique; in the middle area of the labial surface of deciduous or permanent incisors, the acid etching was made with a filter paper disc (∅ 5mm) containing perhydrochloric acid (2M). The disc was removed and shaken in distilled water and the fluoride was determined by a fluoride electrode using a microsample dish.The difference between the mean fluoride contents of deciduous and permanent teeth was not significant ranging from 363 to 540 ppm. There was no increase of fluoride levels of surface enamel with the increase of age.The effect of topical fluoride application was compared on extracted teeth between the pretreatment by either neutral or acidified sodium fluoride or stannous fluoride. The largest retention of fluoride in surface enamel was found after the treatment with phosphate-fluoride solution at pH 3 and the removed calcium by acid was also lowest by this procedure.