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BACKGROUND:Bacterial adhesion is closely related to the surface properties of cobalt-chromium al oys, and therefore, the surface modification technology has become the focus of research in this area. OBJECTIVE:To verify whether the cobalt-chromium al oy with zirconium nitride coating can improve the bacterial adhesion of metal denture materials. METHODS:Magnetron sputtering deposition method was used to plate zirconium nitride film on the surface of cobalt-chromium al oys (experimental group), and cobalt-chromium al oy specimens uncoated served as control group. Streptococcus mutans, Candida albicans, and Actinomyces viscosus were respectively inoculated on the two kinds of test specimen, and at end of culture, the colony counting was done. RESULTS AND CONCLUSION:In the bacterial adhesion test, the number of colonies of three kinds of bacteria in the experimental group was significantly lower than that in the control group (P<0.05). The number of bacterial adhesion in the control group was significantly higher than that in the experimental group. These findings indicate that the cobalt-chromium al oy covered with zirconium nitride coating can significantly reduce the adhesion amount of Streptococcus mutans, Candida albicans and Actinomyces viscosus, and thus improve bacterial adhesion properties of cobalt-chromium al oys.
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OBJECTIVE To investigate the effects and its underlying mechanis m of bisphenol-A (BPA)exposure on spine and synapse formation in detate gyrus (DG)area of hippoca mpus during criti-cal develop mental period.METHODS Sprague-Dawley(SD)rats were injected intraperitoneally with BPA (50,250 and 500 μg·kg -1·d -1 )fro m postnatal day 7 (PND7)to PND14.Dendritic spine morphol-ogy in DG area was exa mined using Golgi-Cox staining method and determined with I mage J software. Western blotting method was e mployed to test the Wnt related proteins.RESULTS The spine density and the average spine head size in BPA exposed groups significantly decreased in a dose-dependent manner when co mpared to control group(P<0.05).Meanwhile,Wnt related proteins were affected dur-ing BPA exposure.Specifically,the percentage of phosphorylated β-catenin increased following BPA ex-posure (P<0.05),whereas Wnt7a expression level was significantly decreased and Wnt5a expression level increased (P<0.05).CONCLUSION Wnt signaling pathway plays an i mportant role in BPA-in-duced i mpairments in spine and synapse formation.