Expression of cathepsin K and IL-6 mRNA in root-resorbing tissue during tooth movement in rats / 中华口腔医学杂志

<p><b>OBJECTIVE</b>To investigate the expression and the localization of Cathepsin K and IL-6 mRNA in root-resorbing tissue and to elucidate the molecular changes and mechanism of root resorption induced by tooth movement.</p><p><b>METHODS</b>Rats were subject to experimental tooth movement to induce root resorption. In situ hybridization was performed to identify the cells in root-resorbing tissue that produced Cathepsin K or IL-6 the difference of CK mRNA or IL-6 mRNA expression between root resorption group and control group was calculated by t-test.</p><p><b>RESULTS</b>Cathepsin K mRNA was highly and selectively expressed in multinuclear odontoclast and IL-6 mRNA expressed in fibroblast, osteoblast, osteocyte and cementoblast. The expression of Cathepsin K mRNA and IL-6 mRNA in root-resorbing tissue increased evidently compared with the normal periodontium.</p><p><b>CONCLUSIONS</b>Odontoclast in the root-resorbing tissue expresses Cathepsin K mRNA that participates in proteolysis during root resorption. IL-6 plays a very important role in the root resorption as a multifunctional cytokine.</p>

In vitro cytotoxicity evaluation of comfort denture adhesive / 华西口腔医学杂志

<p><b>OBJECTIVE</b>The purpose of this study was to evaluate the in vitro cytotoxicity of novel Comfort denture adhesive (Comfort-DA), which was developed by the authors, to human oral fibroblasts (HOFs).</p><p><b>METHODS</b>A sample of Comfort-DA was prepared and extracted in culturing medium to prepare the eluate. Then the eluate was diluted by culturing medium to 50% and 75% concentration for the assessment of cytotoxicity by tetrazolium bromide (MTT) colorimetric assay. Wells containing fresh medium alone were served as control. Cell viability was recorded by optical density after culturing in an atmosphere of 5% CO2 and 95% air at 37 degrees C for 2, 3 and 4 days, respectively. The viability of HOF cells was evaluated by MTT assay to investigate cell proliferation. Optical density (OD) was measured by a spectrophotometer at 490 nm. Then evaluating the cytotoxicity grade in test groups according to the means of cell proliferation. ANOVA was used to test the statistical significance.</p><p><b>RESULTS</b>The statistical analysis of the results of MTT cytological assay indicated significant difference (P < 0.05) in OD (indicate cell viability) between all concentrations of Comfort-DA and the control at all incubation times. The results of cell proliferation percentage also showed that the cytotoxicity grade of tested material only displayed "0-2".</p><p><b>CONCLUSION</b>The generally favorable in vitro cytotoxicity of the Comfort-DA formulations indicates that this product may be an efficacious denture adhesive.</p>