Background This study investigated the effect of post bleaching treatments to the change of enamel elastic modulus and microhardness after dental bleaching in- vitro. Material and Methods Fifty bovine incisor slab were randomly assigned into five groups (n=10). The samples were bleached for three times; 20 minutes each time, by 40% hydrogen peroxide. Next it was applied fractional CO2 laser f...

The force needed to fracture individual human thoracic and lumbar vertebral bodies is compared with the mass and density of apatite. 31P NMR spectrometry was used to quantify the apatite, because it permits the mineral content of bone to be determined noninvasively with minimal nonspecific interference from the organic matrix or from variations in composition of the marrow. Experiments were per...

The bone-bonding ability of a material is often evaluated by examining the ability of apatite to form on its surface in a simulated body fluid (SBF) with ion concentrations nearly equal to those of human blood plasma. However, the validity of this method for evaluating bone-bonding ability has not been assessed systematically. Here, the history of SBF, correlation of the ability of apatite to f...

-Oxygen isotope composition of three types of unique nodules which consist of amorphous silica-apatite, cristobalite-apatite and tridymite-apatite associations interspersed amidst basaltic pyroclastics from the Hat Peres volcano, Golan Heights, Israel is reported. Unusual isotopic temperature (75~ estimated from oxygen isotope fractionation between cristobalite (6'80 = +25.5%0-apatite (6'80 = +...

Bioactive PLLA/surface-grafted silica (g-SiO₂) nanocomposite scaffolds were fabricated by solid-liquid phase separation method. And solid PLLA/g-SiO₂ nanocomposite films were prepared by solution casting method. A series of parallel tube-like morphology and internal ladder-like structure of PLLA/g-SiO₂ nanocomposite scaffolds were observed by SEM. The formation of bone-like apatite in the simul...

The aims of this study were to evaluate the effects of CPP method on the crystallinity of apatite powder and on the acid resistance of bovine enamel. Crystallinity degrees of apatite powder before and after CPP treatment were measured by powder X-ray diffraction analysis. Polished bovine enamel specimens treated with CPP method or NaF were immersed in a lactic acid solution for up to five days....

Introduction: The magmatic volatiles water, fluorine, and chlorine play critical roles in the physicochemical processes that control thermal stabilities of minerals and melts, magma eruptive processes, and transport of economically important metals. While these volatiles are significant constituents in many terrestrial and martian magmas, lunar magmas are generally depleted in these three volat...

Liu et al. [1] explained the possible cariostatic mechanisms of the combined fluoride-laser treatment. They suggested that a laser-induced purification of the human enamel hydroxy apatite structure takes place and plays the major role in this cariostatic process. They also mentioned that the low-energy laser treatment has a photo thermal effect that may cause a reduction in enamel permeability....

Many advances have been made in radiocarbon dating of bone organics, but research on 14C dating of bone inorganic carbon has lagged significantly behind. Using mammoth bone, enamel, and tusk from the Dent and Murray Springs Clovis sites, experiments with the Haas and Banewicz technique of bone apatite dating by step heating demonstrate that accurate radiocarbon ages can be produced from bone ap...

Microorganisms are ubiquitous in the shallow subsurface often attached to sediment surfaces where they alter the geochemical microenvironment and mediate weathering reactions. Microbial attachment on sediment grains, however, is heterogeneous and the variability of microbial occurrence cannot be easily explained. This study examined how phosphate mineral and iron oxide inclusions in feldspars i...