The effects of third-order torque and self - Saint Louis University

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LIST OF FIGURES Figure 3-1: Four cylinders mounted in aluminum base plate of the friction testing device......84 Figure 3-2: Bracket-slot positioning template.........84 Figure 3-3: Control of the third-order position of the second premolar bracket-slot..............85 Figure 3-4: SLBUCCAL tube.............................85 Figure 3-5: Damon 3MX bracket.........................85 Figure 3-6: SmartClip bracket.........................86 Figure 3-7: In-Ovation R bracket......................86 Figure 3-8: Time2 bracket.............................86 Figure 3-9: Victory bracket...........................87 Figure 3-10: Friction testing setup mounted to the Instron Universal Testing Machine.........87 Figure 3-11: Plots of mean kinetic frictional force within the dental segment vs. torque angle at the second premolar from five sets of crown-attachments.........................88 Figure 3-12: Cross-section diagrams of a 0.019- x 0.025inch wire. The buccolingual dimension of the wire when rotated 10 degrees (line BD) is calculated by multiplying cosΦ2 by the hypotenuse AB.............................89 vi
CHAPTER 1: INTRODUCTION The specialty of orthodontics has been going through a period of considerable research interest in the role of friction during tooth movement. Within the past 30 years, studies have focused on both the contact between the wire and the bracket- or tube-slot as a potential source of frictional resistance during sliding mechanics and the many associated factors that can affect that resistance to tooth movement. These experiments have identified variables in the archwire, bracket, ligature and oral environment as contributors to frictional forces. With recent advances in orthodontic technologies, such as new self-ligating bracket designs and archwire alloys, orthodontists have developed systems aimed at maximizing the efficiency of treatment. Today fewer archwires are placed, and treatment phases have been merged that were previously carried out individually. The gaining popularity of sliding mechanics has made further research on the role of friction necessary. Previous studies have evaluated friction by pulling the wire through the bracket-slot and measuring the force required to produce the sliding displacement. Many investigations have examined single brackets with various 1
Page 1 and 2: THE EFFECTS OF THIRD-ORDER TORQUE A
Page 3 and 4: of torque, all five attachment sets
Page 5 and 6: COMMITTEE IN CHARGE OF CANDIDACY: A
Page 7 and 8: ACKNOWLEDGEMENTS The author wishes
Page 9: LIST OF TABLES Table 2-1: Partial O
Page 13 and 14: CHAPTER 2: REVIEW OF THE LITERATURE
Page 15 and 16: surfaces. 6 The magnitudes of the c
Page 17 and 18: Since the introduction to orthodont
Page 19 and 20: that the application of the Amonton
Page 21 and 22: archwires. At binding angulations,
Page 23 and 24: A phenomenon known as “cold weldi
Page 25 and 26: of round wire with the slot created
Page 27 and 28: acket and the gold-lined Luxi brack
Page 29 and 30: and wire stiffness. As bracket widt
Page 31 and 32: ligation-friction relationship. The
Page 33 and 34: designs have been introduced to the
Page 35 and 36: otated tooth or a twisted rectangul
Page 37 and 38: to incisor irregularity after initi
Page 39 and 40: added. Similarly, Bunkall 15 noted
Page 41 and 42: couple, resulting in the delivery i
Page 43 and 44: Another factor that influences brac
Page 45 and 46: References 1. Stoner MM. Force cont
Page 47 and 48: 19. Kusy RP, Whitley JQ, Ambrose WW
Page 49 and 50: 37. Kusy RP, Whitley JQ, Mayhew MJ,
Page 51 and 52: 56. Khambay B, Millett D, McHugh S.
Page 53 and 54: 75. Tecco S, Festa F, Caputi S, Tra
Page 55 and 56: 93. Thorstenson GA, Kusy RP. Effect
Page 57 and 58: Tables Table 2-1: Partial Overview
Page 59 and 60: significantly less friction than th
Page 61 and 62:
optimal clinical results. Fixed-app
Page 63 and 64:
self-ligating bracket systems to ma
Page 65 and 66:
unconstrained rotation around the l
Page 67 and 68:
surface of a tooth-crown. The const
Page 69 and 70:
0.025-inch NuBryte Standard Arch st
Page 71 and 72:
test-archwire in place and ligated,
Page 73 and 74:
aseline values at 0 degrees of torq
Page 75 and 76:
increased to only five degrees. The
Page 77 and 78:
tension on one edge of the wire and
Page 79 and 80:
set, when the torque angle was incr
Page 81 and 82:
with active, self-ligating sets. Th
Page 83 and 84:
11. Kusy RP, Whitley JQ. Effects of
Page 85 and 86:
33. Andreasen GF, Quevedo FR. Evalu
Page 87 and 88:
54. Downing A, McCabe JF, Gordon PH
Page 89 and 90:
76. Thorstenson GA, Kusy RP. Effect
Page 91 and 92:
Table 3-2: Significance levels (α
Page 93 and 94:
Table 3-4: Mean differences in fric
Page 95 and 96:
Figure 3-3: Control of the third-or
Page 97 and 98:
Figure 3-9: Victory bracket Figure
Page 99 and 100:
Figure 3-12: Cross-section diagrams
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The effects of third-order torque and self - Saint Louis University

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