In vivo Use of a Dual Acid Etch Biopsy for the Evaluation of Lead Profiles in Human Surface Enamel

Abstract. Two successive acid etch biopsies were performed on the permanent maxillary right central incisors of two age-groups of children resident in an urban area in Belgium. Lead was determined in the biopsy solutions and the concentrations were related toetch depths which were calculated from the calcium and phosphorus concentrations in the biopsy solutions. The mean lead concentration of the first enamel biopsy layer was five times higher than in the second biopsy layer. A strong relation was observed between the two biopsies. It was shown that calibration of the lead values with respect to etch depths and Ca/P ratios was desirable and that a robust regression analysis approach was needed instead of classic least-squares regression analysis. However, the second biopsy provided more reliable lead estimates. In this study no increase in lead concentration in surface enamel could be demonstrated with age. Therefore, it was concluded that for these children the presence of lead in surface enamel had to be attributed primarily to preeruptive uptake.info:eu-repo/semantics/publishe