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

作者：Pliska Benjamin T^*; Beyer John P; Larson Brent E

来源：The Angle Orthodontist, 2011, 81(5): 794-799.

DOI：10.2319/111510-666.1

• Friction
• Self-ligating
• Resistance to sliding

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 AS 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 '' x 0.025 '' SS and NT archwires. The AS 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. (Angle Orthod. 2011;81:794-799.)

• 出版日期2011-9