Zircon (ZrSiO4) is a small mineral highly resistant to chemical changes; this robustness has led it to be used for estimating earth conditions eons ago. It has been used to date geologic events, measuring its radiogenic Pb, U and Th isotopes. The oldest dated mineral on Earth is a zircon from Australia, and its oxygen isotope value suggests Earth’s crust was cool and wet as long ago as 4.3 bill...

BACKGROUND There are a number of studies citing the primary reason for replacing auto cure glass ionomer cements was due to recurrent caries. The purpose of this study was to use an in vitro model to measure caries at the dentine restoration interface of bonded composite resin and auto cure glass ionomer cement restorations and to measure the amount of surface degradation occurring in the resto...

BACKGROUND There have been numerous attempts to demonstrate the phenomenon of ion exchange between auto cure glass ionomer cements (GICs) and dentine. The purpose of this study was to employ an electron probe microanalysis (EPMA) technique to examine the interchange of elements between non-demineralized dentine and two types of restorative material, auto cure GICs and a resin composite. METHO...

Abstract Gallium (Ga) and germanium (Ge) are technologically important critical elements. Lead blast furnace slags from Tsumeb, Namibia, comprise over two million metric tons of material that contains high levels Ga (135–156 ppm) Ge (128–441 in addition to significant Zn concentrations (up 11 wt.%) represent a potential resource for these A combination mineralogical chemical methods (PXRD, FEG-...