Papers by Author: Xing Yi Li

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Authors: Xiang Cai Meng, Xing Yi Li, Tao Wang
Abstract: The paper deals with a kind of new method of the electro-deposition on titanium by a cathode revolves. The depositing characteristic and mechanic were studied by scanning electron microscopy and X-ray diffraction. The experimental results show that the more fine uniformity and compact calcium phosphate bioactive coatings could be produced, compared with the conventional methods. The gradient Coating, which is fine inside and porous outside, could be obtained by controlling revolving velocity. The coating would transform to the hydroxyapatite after heat-treatment. After soaking in a simulated body fluid (SBF), nano-depositions were formed on the surface of the coating, then those particles would grow up needle-like, net-like, and an apatite-like layer could be observed finally. The gradient porosity coatings produced by cathode revolving electrochemical deposition would have high anti-dissolution and bioactive.
1525
Authors: Kui Long Lu, Xiang Cai Meng, Jiu Xing Zhang, Xing Yi Li, Mei Ling Zhou
Abstract: The objective of this study was to investigate the inhibitory effect of the synthetic nanohydroxyapatite (HA) on dental caries. The nano-HA was synthesized by using the depositing reaction of Ca (H2PO4)2. The artificial dental caries was made by using sour solution and inoculating Streptococcus mutans (S.mutans) to the Sprague-Dawley (SD) rat’s mouth respectively. After mineralization of solution of nano-HA for 10 days, the hardness of enamel was measured. The inhibitory effect of the synthetic nano-HA on dental caries was detected by gargling way to rinse the rat tooth with the solution of nano-HA in the animal test. Transmission electron microscopy (TEM) revealed that the dried HA particles were needle-like with ф5-20nm×60nm and the sintered HA particles were spherical with less than 100nm. The remineralized test indicated that the solution of nano-HA with different shapes enhanced the hardness of artificial caries and improved the remineralization of artificial caries. The animal test showed that the dried nano-HA had the inhibitory effect on dental caries. The good absorptive effect of the nano-HA on both the saliva protein and the glucans leads to the development of interventions that could reduce or modify bacterial colonization of tooth surfaces.
1538
Authors: Kui Long Lv, Jiu Xing Zhang, Xiang Cai Meng, Xing Yi Li
Abstract: The aim of this study is to describe the remineralization effect of the nano-HA toothpaste on artificial caries. The artificial dental caries is made using sour solution. The demineralized teeth specimen is put into five kinds of toothpaste solution respectively for 5 days and 10 days, which are: solution of containing needle like nano-HA, solution of containing spherical nano-HA, solution of general HA, fluorine sodium solution and physiological saline. The hardness of specimen is measured and the surface morphology is characterized by SEM. The remineralized test indicates that the nano-HA toothpaste can enhance the hardness of artificial caries and improve the remineralization of artificial caries. The SEM analysis shows that the cavities and defects of enamel surface are decreased and many mineral salts are sedimentated, which indicate that the nano-HA could promote remineralization for the demineralized enamel.
267
Authors: Kui Long Lv, Hai Wen Yuan, Xiang Cai Meng, Xing Yi Li
Abstract: The aim of this study is to describe the remineralization effect of the nano-HA on artificial caries. The artificial dental caries are made by using sour solution, and constructing an artificial mouth' plaque culture system in vitro respectively. The scanning electron microscope (SEM) and the optical microscope are used to observe the surface of enamel specimens. The effect of remineralization is assessed with the polarized light microscopy (PLM) and the confocal laser scanning microscope (CLSM) by measuring three lesion parameters (area, total and average fluorescence). The SEM analysis shows that the cavities and defects of enamel surface are decreased and many mineral salts are sedimentated, which indicate that the nano-HA could promote remineralization for the demineralized enamel. The inhibitory effect of the spherical nano-HA on dental caries is detected in the artificial mouth test. The CLSM shows that demineralization of enamel is reduced by adding the spherical nano-HA in artificial mouth. The results show that the spherical nano HA have a remineralization effect on the artificial dental caries dramatically, and can prevent and decrease caries.
576
Authors: Xiang Cai Meng, Xing Yi Li, Kui Long Lu
Abstract: The hydroxyapatite (HA) particle with different morphologies were prepared by adding a certain additive into Ca(H2PO4)2·H2O and controlling the bathing and sintering temperature, and the pure needle-like HA sol were obtained when the bathing temperature was 70°C. The experimental results show that the degree of crystallization of HA increase and the particles tend to accumulate with increasing of the drying and sintering temperatures. The particles of HA were spheroid, which diameters were of less than 100nm when they were sintered at the temperature of 700°C. The effect of nano-hydroxyapatite on remineralization of early enamel caries were studied too. The hardness of dismineralized enamel was increased when dismineralized enamel was remineralized by nano-hydroxyapatite. The SEM analysis shows that the interspace of enamel surface were decreased and the many mineral salts were sedimentated, which indicated that the nano-hydroxyapatie could promote remineralization for the dismineralized enamel.
2423
Authors: Xing Yi Li, Guo Quan Liu, Shi Dan Yuan, Ling Zhang, Xiang Cai Meng
Abstract: The Nano-HA powder was prepared by chemical precipitation. Magnesium powders were used to make porous ultramicron HA ceramic, and the biological properties of which were investigated by hemolysis rate and cytotoxicity tests. The experimental results shows that the hemolysis rate of the nano-HA powder and porous ultramicron HA ceramic were all less than 5% and none of them showed cytotoxicity. The results indicated that nano-HA and porous ultramicron HA ceramic were provided with good biocompatibility.
1215
Authors: Xing Yi Li, Xiang Cai Meng, Guo Quan Liu, Shi Dan Yuan
Abstract: The Nano-HA powder were synthesized by chemical precipitation with Ca(H2PO4)2•H2O and Ca (OH)2 and porous HA was prepared by sintering with magnesium as pore-creator. Nano-HA powder and porous HA were characterized by wide angle X-ray diffraction, transmission electron microscopy(TEM), scanning electron microscopy (SEM), SEM in combination with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray photoelectron spectroscopy. The experimental results show that HA powder synthesized by chemical precipitation is nanometer powder. Magnesium was ideal pore-creator for preparation of porous materials. The grain size of porous HA was sub-micron and MgO which existed in the grain boundary of HA as a second phase particles that played the roles of inhibiting the HA grain growth.
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