X-Ray Fluorescence with Synchrotron Radiation to Analysis in teeth

Introduction:Studies have shown that teeth are valuable biomarkers of trace elements. However, some biological differences in dental tissues result in differences in the distribution of elements in various anatomical locations, and those differences have been overlooked in many studies. Objective: this study aimed at determining variations in the spatial distribution of Ca, K, Zn, Pb, Mn, Cu, and Sr in four anatomical locations: superficial enamel (SE, 0-10 um) and subsuperficial enamel (SSE, 10-30 um), primary dentine (PD), and secondary dentine (SD) of primary incisors by micro Synchrotron Radiation X-Ray Fluorescence (µ-SRXRF), a semiquantitative technique with spacial resolution. Methods: Two of the 5 teeth selected for this study had low superficial enamel concentrations of lead (< 250 ug/g), while 3 were included for their very high superficial enamel lead concentrations (> 2,000 ug/g). On each tooth section five spot measurements (20 µm beam diameter) were made in the four anatomical locations (SE, SSE, PD, and SD). The data are shown as absolut values and as the ratio of the different elements by Ca. Results: K showed a distribution that closely followed that of Ca. Zn was the third most abundant element found, with the highest levels of Zn found in SE and SD, and low levels found in PD in all 5 teeth. Increasing levels of Sr were found from the enamel to dentine, with the highest levels found in SD, a unique distribution found among the elements tested. Pb, Mn, and Cu showed a similar trend. Higher amounts of Pb were found in the SE. Conclusion: In conclusion, this study confirms the heterogeneous distribution of different elements in teeth, clearly highlighting the importance of the first 10 um of SE for the determination of some elements, such as Zn, Pb, Mn, and Cu.