Effect of internal stress on cyclic fatigue failure in .06 taper ProFile

OBJECTIVES: The purpose of this study was to evaluate the relation between intentionally induced internal stress and cyclic fatigue failure of .06 taper ProFile. MATERIALS AND METHODS: Length 25 mm, .06 taper ProFile (Dentsply Maillefer), and size 20, 25, 30, 35 and 40 were used in this study. To give the internal stress, the rotary NiTi files were put into the .02 taper, Endo-Training-Bloc (Dentsply Maillefer) until auto-stop by torque controlled motor. Rotary NiTi files were grouped by the number of induced internal stress and randomly distributed among one control group and three experimental groups (n = 10, Stress 0 [control], Stress 1, Stress 2 and Stress 3). For cyclic fatigue measurement, time for separation of the rotary NiTi files was recorded. The fractured surfaces were observed by field emission scanning electron microscope (FE-SEM, SU-70, Hitachi). The time for separation was statistically analyzed using two-way ANOVA and post-hoc Scheffe test at 95% level. RESULTS: In .06 taper ProFile size 20, 25, 30, 35 and 40, there were statistically significant difference on time for separation between control group and the other groups (p < 0.05). CONCLUSION: In the limitation of this study, cyclic fatigue failure of .06 taper ProFile is influenced by internal stress accumulated in the files.

Changes of Interleukin-10 and Granulocyte Colony-Stimulating Factor in Cerebrospinal Fluid of Children with Aseptic Meningitis

PURPOSE: Interleukin(IL)-10 is an antiinflammatory cytokine produced by monocytes/macrophages. Granulocyte colony-stimulating factor(G-CSF) plays an important role, not only as a hemopoietic factor but also as a regulating factor for a biologic defense system by neutrophils, in the foci of infection. We studied G-CSF and IL-10 levels in the serum and cerebrospinal fluid(CSF) of patients with aseptic meningitis and investigated the relationship of G-CSF and IL-10 with other inflammatory cells. METHODS: We measured IL-10 and G-CSF levels in the serum and CSF of children with or without aseptic meningitis using ELISA and compared them with other inflammatory cells in the CSF. RESULTS: CSF levels of IL-10 & G-CSF on admission were significantly higher in the aseptic meningitis group than in the control group. IL-10 and G-CSF levels in the CSF were higher than those in the serum(P<0.001). Mean CSF IL-10 & G-CSF levels during the recovery stage decreased significantly compared to those of the symptomatic stage(P<0.001). Significant correlations were found between CSF IL-10 levels and mononuclear cell counts(r=0.26, P<0.05), and between G-CSF levels and neutrophil counts in the CSF(r=0.44, P<0.005). CSF levels of G-CSF were highest on the 1st day of the illness, although CSF IL-10 levels reached its peak on the 3rd day of the illness. CONCLUSION: IL-10 and G-CSF are produced in the CSF of patients with aseptic meningitis and may play an immunoregulatory role by recruiting inflammatory cells from the peripheral blood at the initial stage of aseptic meningitis.

Changes of Interleukin-10 and Granulocyte Colony-Stimulating Factor in Cerebrospinal Fluid of Children with Aseptic Meningitis

PURPOSE: Interleukin(IL)-10 is an antiinflammatory cytokine produced by monocytes/macrophages. Granulocyte colony-stimulating factor(G-CSF) plays an important role, not only as a hemopoietic factor but also as a regulating factor for a biologic defense system by neutrophils, in the foci of infection. We studied G-CSF and IL-10 levels in the serum and cerebrospinal fluid(CSF) of patients with aseptic meningitis and investigated the relationship of G-CSF and IL-10 with other inflammatory cells. METHODS: We measured IL-10 and G-CSF levels in the serum and CSF of children with or without aseptic meningitis using ELISA and compared them with other inflammatory cells in the CSF. RESULTS: CSF levels of IL-10 & G-CSF on admission were significantly higher in the aseptic meningitis group than in the control group. IL-10 and G-CSF levels in the CSF were higher than those in the serum(P<0.001). Mean CSF IL-10 & G-CSF levels during the recovery stage decreased significantly compared to those of the symptomatic stage(P<0.001). Significant correlations were found between CSF IL-10 levels and mononuclear cell counts(r=0.26, P<0.05), and between G-CSF levels and neutrophil counts in the CSF(r=0.44, P<0.005). CSF levels of G-CSF were highest on the 1st day of the illness, although CSF IL-10 levels reached its peak on the 3rd day of the illness. CONCLUSION: IL-10 and G-CSF are produced in the CSF of patients with aseptic meningitis and may play an immunoregulatory role by recruiting inflammatory cells from the peripheral blood at the initial stage of aseptic meningitis.