The surface structure and antibacterial property of Ag-containing coating on casting cobalt chromium alloy / 实用口腔医学杂志

Objective:To study the surface structure and antibacterial property of Ag-containing coating(AgCC)on casting cobalt chromium alloy(Co-Cr).Methods:Plasma spraying technique was adopted to prepare AgCC on Co-Cr.Scanning electron microsco-py,energy dispersive analysis and X-ray diffraction analysis were used to evaluate the surface properties.The antibacterial effects of AgCC against staphylococcus aureus and candida albicans were examined by film attachment method.Fluorescence microscope was a-dopted to evaluate the bacteria adhesion property.Results:AgCC surface was uniform and compact,combined perfectly with sub-strate material.The content of the surface was mainly Ag,Cr and a small amount of Ag2 O and Cr2 O3 .The results of antibacterial as-say showed that on AgCC the number of bacterial colony was fewer(P<0.05)and bacterial adhesion was less than those on Co-Cr(P<0.05).Conclusion:AgCC surface was stable and has antibacterial property.

The experiment study of several resin-removal methods on enamel surface / 重庆医学

Objective To observe the effect of several residual adhesive methods on the enamel surface ,and conduct lab evalua-tion .Methods Sixty premolars extracted because of orthodontic treatment .And all the teeth were randomly divided into 3 groups . Group 1:tungsten carbide burs + silicon particles ;Group 2 :ultrasonic scaling + silicon particles ;Group 3:silicon particles ,each with 20 premolars .After underwent several methods ,the surface roughness differences ,operation time were determined and ob-served with the scanning electron microscope .And the result was statistically analyzed .Results There were significant differences in the surface roughness and operation time among the three groups (P<0 .05) ,The scanning electron microscope after polishing showed that the teeth surface had different degrees of injury ,the silica particles group had less superficial scratch .Conclusion The tungsten carbide burs and ultrasonic instrument for debonding before the silica particles had less superficial scratch .

Effect of alendronate on expressions of osteoprotegerin and receptor activator of nuclear factor κB ligand in mouse osteoblasts / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the effect of alendronate on the expressions of osteoprotegerin (OPG) and receptor activator of nuclear factor-κB ligand (RANKL) in mouse osteoblasts.</p><p><b>METHODS</b>Mouse calvarial osteoblasts cultured in vitro were identified by alkaline phosphatase (ALP) staining and immunofluorescence assay of OPG and RANKL expressions. The second passage of the osteoblasts were treated with different concentrations of alendronate (10(-4) to 10(-7) mol/L) for 48 h, and the changes in OPG and RANKL mRNA and protein expressions were examined using real-time PCR and Western blotting, respectively.</p><p><b>RESULTS</b>The isolated osteoblasts were positive for ALP and expressed OPG and RANKL. Real-time PCR and Western blotting showed that at the concentration of 1×10(-4) mol/L, alendronate caused an obvious down-regulation of OPG and RANKL expressions in the cells, whereas at lower concentrations, alendronate increased the expressions of both genes with the highest expressions occurring after treatment with 1×10(-5) mol/L.</p><p><b>CONCLUSION</b>High concentrations of alendronate (>1×10(-4) mol/L) decrease the expressions of OPG and RANKL, whereas low concentrations (1×10(-5) to 1×10(-7) mol/L) increase their expressions in mouse osteoblasts cultured in vitro.</p>