Comparison of resistance to sliding between different self-ligating brackets with second-order angulation in the dry and saliva states

2002 ◽  
Vol 121 (5) ◽  
pp. 472-482 ◽  
Author(s):  
Glenys A. Thorstenson ◽  
Robert P. Kusy
Keyword(s):  
Second Order ◽  
Resistance To Sliding

scholarly journals A comparison of resistance to sliding of self-ligating brackets under an increasing applied moment

2011 ◽  
Vol 81 (5) ◽  
pp. 794-799 ◽  
Author(s):  
Benjamin T. Pliska ◽  
John P. Beyer ◽  
Brent E. Larson
Keyword(s):  
Stainless Steel ◽  
Analysis Of Variance ◽  
Continuous Measurement ◽  
Second Order ◽  
Nickel Titanium ◽  
Order Dimension ◽  
Canine Retraction ◽  
Resistance To Sliding ◽  
Post Test

Abstract Objective: To test the null hypotheses that at clinically relevant amounts of applied moment, there are no differences in the amount of resistance to sliding (RS) between self-ligating (SL) and conventionally ligated (CL) brackets on both stainless steel (SS) and nickel-titanium (NT) archwire. Materials and Methods: Three different SL brackets and one CL bracket, all 0.022″ slot, were tested on a custom-built device to simulate canine retraction mechanics in the second-order dimension. The setup allowed for simultaneous and continuous measurement of RS and applied moment at the bracket-archwire interface. The brackets tested were Damon3, In-Ovation R, Smartclip, and Victory, all of which were tested with 0.019″ × 0.025″ SS and NT archwires. The RS at calculated moments of 2000 g-mm and 4000 g-mm was determined and compared between the various brackets and both archwire types. Descriptive measures, analysis of variance, and Tukey-Kramer post-test comparisons were used to calculate results. Results: All brackets displayed a greater amount of RS with NT than with SS archwires. At the higher moment levels (4000 g-mm), no significant reduction in RS was found between CL and SL brackets on both SS and NT archwires. At lower levels of applied moment (2000 g-mm), reductions in RS of 18% (42.7 g) and 18% (38.5 g) were found between the CL bracket and the best performing SL bracket on NT and SS, respectively. Conclusion: At low values of applied moment, some statistical differences were found; however, in general, the differences in RS amongst the various SL and CL brackets tested may not be clinically relevant.

scholarly journals The effect of perturbations on resistance to sliding in second-order moments comparing two different bracket types

2014 ◽  
Vol 5 (0) ◽  
Author(s):  
J. K. Wong ◽  
D. L. Romanyk ◽  
R. W. Toogood ◽  
G. Heo ◽  
J. P. Carey ◽  
...  
Keyword(s):  
Second Order ◽  
Resistance To Sliding

scholarly journals Effect of applied moment on resistance to sliding among esthetic self-ligating brackets

2013 ◽  
Vol 84 (1) ◽  
pp. 134-139 ◽  
Author(s):  
Benjamin T. Pliska ◽  
Rick W. Fuchs ◽  
John P. Beyer ◽  
Brent E. Larson
Keyword(s):  
Stainless Steel ◽  
Analysis Of Variance ◽  
Second Order ◽  
The Other ◽  
Order Dimension ◽  
Testing Apparatus ◽  
Canine Retraction ◽  
Resistance To Sliding ◽  
Sliding Mechanics

ABSTRACT Objective: To determine the effect of mode of ligation and bracket material on resistance to sliding (RS) by comparing various esthetic brackets of conventionally ligated and self-ligating (SL) designs under an increasing applied moment in the second-order dimension. Materials and Methods: Eight different commercially available esthetic brackets of SL and conventional elastomeric-ligated (CL) designs were mounted on a testing apparatus to simulate canine retraction using sliding mechanics and the application of a moment on 0.019″×0.025″ stainless steel archwire. The samples examined were the CL brackets Clarity™, Inspire Ice™, SpiritMB™, and Mystique™, and the SL brackets ClaritySL™, In-OvationC™, In-OvationR™, and Smartclip™. The RS at calculated moments of 2000 g-mm and 4000 g-mm was determined and compared between the various brackets. Descriptive measures and one-way analysis of variance were used to calculate means and statistical differences among the bracket types. Results: The CL monocrystalline bracket displayed significantly greater (P < .05) RS than all other brackets tested. Among the other brackets, the range of RS values was 145.8–191.7 g and 291.9–389.2 g at moments of 2000 g-mm and 4000 g-mm, respectfully, though these differences were not significant (P < .05). All brackets tested displayed greater levels of RS (P < .05) at 4000 g-mm than at 2000 g-mm. Conclusion: With the exception of the CL monocrystalline bracket, all brackets displayed comparable amounts of RS regardless of mode of ligation or bracket slot material.

Disappearance Voltage Determinations Using a Convergent Beam

1971 ◽  
Vol 29 ◽  
pp. 184-185
Author(s):  
W. L. Bell
Keyword(s):  
Second Order ◽  
Objective Method ◽  
Uniform Thickness ◽  
Rocking Curve ◽  
Crystal Perfection ◽  
Kikuchi Line ◽  
Central Maximum ◽  
Diffraction Patterns ◽  
Convergent Beam ◽  
Beam Technique

Disappearance voltages for second order reflections can be determined experimentally in a variety of ways. The more subjective methods, such as Kikuchi line disappearance and bend contour imaging, involve comparing a series of diffraction patterns or micrographs taken at intervals throughout the disappearance range and selecting that voltage which gives the strongest disappearance effect. The estimated accuracies of these methods are both to within 10 kV, or about 2-4%, of the true disappearance voltage, which is quite sufficient for using these voltages in further calculations. However, it is the necessity of determining this information by comparisons of exposed plates rather than while operating the microscope that detracts from the immediate usefulness of these methods if there is reason to perform experiments at an unknown disappearance voltage.The convergent beam technique for determining the disappearance voltage has been found to be a highly objective method when it is applicable, i.e. when reasonable crystal perfection exists and an area of uniform thickness can be found. The criterion for determining this voltage is that the central maximum disappear from the rocking curve for the second order spot.

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