Introduction: During sliding mechanics, frictional resistance is an important counterforce to orthodontic tooth movement; which must be controlled to allow application of light continuous forces. objective: To investigate static and kinetic frictional resistance between three orthodontic brackets: ceramic, self-ligating, and stainless steel, and three 0.019×0.025” archwires: stainless steel, ni...

UNLABELLED Self-ligating brackets engage the wire by means of a slide mechanism. Forces that have to be applied to open and close the sliding mechanism of brackets are still unknown. OBJECTIVE The aim of this study was to measure and compare the opening and closure forces of different self-ligating brackets. MATERIAL AND METHODS Three different stainless steel self-ligating brackets (Carrie...

BACKGROUND It has been demonstrated that fluoride prophylactic agents may cause hydrogen absorption in NiTi wires and degrade their mechanical properties. AIMS To investigate the effect of a fluoride mouthwash on load-deflection characteristics of three types of nickel-titanium-based orthodontic archwires. METHODS Twenty maxillary 0.016 inch round specimens from each of the single-strand Ni...

The first day of the meeting consisted of a series of presentations by working group members using CCSM (or closely related models) to study the climate. These studies could be loosely categorized into three topics: the effects of sea ice on constituents of the global climate, fresh water fluxes in the ocean, and Arctic clouds. All presentations dealt primarily with the Northern Hemisphere. The...

Metabolism by peptidases plays an important role in modulating the levels of biologically active neuropeptides. One of these neuropeptides, substance P (SP), a component of gingival crevicular fluid (GCF), may exponentiate the inflammatory process during orthodontic tooth movement. The aim of this study was to investigate the GCF levels of SP in patients using different bracket systems. Subject...

The relaxation mechanisms in thin nickel films are investigated with all optical pump-probe experiments. Magnetic oscillations in the GHz range can be attributed to the uniform precession (Kittel mode) and spin waves with dipole character (Damon-Eshbach surface modes). Applying an external field changes both oscillation amplitude and frequency yielding experimental dispersions ν(Hext). On a wed...

Using the 12 published results from the 1988 radiocarbon dating of the TS (Turin Shroud), a robust statistical analysis has been performed in order to test the conclusion by Damon et al. (1998) that the TS is mediaeval. The 12 datings, furnished by the three laboratories, show a lack of homogeneity. We used the partial information about the location of the single measurements to check whether t...

BACKGROUND The aim of this study was to compare the deflection force in conventional and thermally activated nickel-titanium (NiTi) wires in passive (Damon Q) and active (Bioquick) self-ligating brackets (SLB) and in conventional brackets (CB) tied by two different methods: elastomeric ligature (EL) and metal ligature (ML). METHODS Two wire diameters (0.014 and 0.016 in.) and 10 specimens per...