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

Wong JK, Romanyk DL, Toogood RW, Heo G, Carey JP, Major PW - J Dent Biomech (2014)

Bottom Line: Results for conventional brackets in the presence of perturbations at 0 degrees showed there was a statistically significant reduction (P<0.001) in RS when compared to controls.However, at 6 degrees high perturbation groups both resulted in statistically significant (P<0.001) reductions in RS when compared to controls.From this study it was concluded that passive ligated brackets have a lower RS when compared to conventional ligated brackets under all test conditions and angulations.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthodontics, School of Dentistry, Faculty of Medicine & Dentistry, Edmonton Clinic Health Academy, University of Alberta, Edmonton, AB, Canada.

ABSTRACT
Orthodontic literature has shown all ligation methods to behave similarly in the clinical situation; however, the reasoning behind this still requires further investigation. A novel frictional device able to measure forces at the level of the bracket along with a custom perturbation device was used to investigate the effect of perturbations on resistance to sliding (RS) using conventional and passive ligated brackets. 150 3M Victory Series twins (0.022 slot) and 150 Damon Q brackets (0.022 slot) were tested using an 0.018 x 0.025 stainless steel wire for RS. There were 5 test groups consisting of equal numbers (n=30) representing combinations of high and low amplitude and frequency of perturbations along with a control. Second order angulation tested ranged from 0 to 6 degrees. Results for conventional brackets in the presence of perturbations at 0 degrees showed there was a statistically significant reduction (P<0.001) in RS when compared to controls. At 6 degrees, this difference (P<0.001) was seen in both high perturbation groups and one of the low perturbation groups. For passive ligated brackets, no statistically significant difference between groups was seen at 0 degrees. However, at 6 degrees high perturbation groups both resulted in statistically significant (P<0.001) reductions in RS when compared to controls. From this study it was concluded that passive ligated brackets have a lower RS when compared to conventional ligated brackets under all test conditions and angulations. Also, amplitude of perturbations has a larger role than frequency in reduction of RS values.

No MeSH data available.


Graph of second-order movement versus resistance to sliding for conventional ligated (CL) brackets.LF: low frequency; HF: high frequency; LP: low perturbations; HP: high perturbation.
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fig5-1758736014557500: Graph of second-order movement versus resistance to sliding for conventional ligated (CL) brackets.LF: low frequency; HF: high frequency; LP: low perturbations; HP: high perturbation.

Mentions: The relation between RS and tip angle for the two ligation methods and various perturbation conditions are shown in Figure 5 (conventional ligation) and Figure 6 (passive ligation).


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

Wong JK, Romanyk DL, Toogood RW, Heo G, Carey JP, Major PW - J Dent Biomech (2014)

Graph of second-order movement versus resistance to sliding for conventional ligated (CL) brackets.LF: low frequency; HF: high frequency; LP: low perturbations; HP: high perturbation.
© Copyright Policy - creative-commons
Related In: Results  -  Collection

License 1 - License 2 - License 3
Show All Figures
getmorefigures.php?uid=PMC4228925&req=5

fig5-1758736014557500: Graph of second-order movement versus resistance to sliding for conventional ligated (CL) brackets.LF: low frequency; HF: high frequency; LP: low perturbations; HP: high perturbation.
Mentions: The relation between RS and tip angle for the two ligation methods and various perturbation conditions are shown in Figure 5 (conventional ligation) and Figure 6 (passive ligation).

Bottom Line: Results for conventional brackets in the presence of perturbations at 0 degrees showed there was a statistically significant reduction (P<0.001) in RS when compared to controls.However, at 6 degrees high perturbation groups both resulted in statistically significant (P<0.001) reductions in RS when compared to controls.From this study it was concluded that passive ligated brackets have a lower RS when compared to conventional ligated brackets under all test conditions and angulations.

View Article: PubMed Central - PubMed

Affiliation: Department of Orthodontics, School of Dentistry, Faculty of Medicine & Dentistry, Edmonton Clinic Health Academy, University of Alberta, Edmonton, AB, Canada.

ABSTRACT
Orthodontic literature has shown all ligation methods to behave similarly in the clinical situation; however, the reasoning behind this still requires further investigation. A novel frictional device able to measure forces at the level of the bracket along with a custom perturbation device was used to investigate the effect of perturbations on resistance to sliding (RS) using conventional and passive ligated brackets. 150 3M Victory Series twins (0.022 slot) and 150 Damon Q brackets (0.022 slot) were tested using an 0.018 x 0.025 stainless steel wire for RS. There were 5 test groups consisting of equal numbers (n=30) representing combinations of high and low amplitude and frequency of perturbations along with a control. Second order angulation tested ranged from 0 to 6 degrees. Results for conventional brackets in the presence of perturbations at 0 degrees showed there was a statistically significant reduction (P<0.001) in RS when compared to controls. At 6 degrees, this difference (P<0.001) was seen in both high perturbation groups and one of the low perturbation groups. For passive ligated brackets, no statistically significant difference between groups was seen at 0 degrees. However, at 6 degrees high perturbation groups both resulted in statistically significant (P<0.001) reductions in RS when compared to controls. From this study it was concluded that passive ligated brackets have a lower RS when compared to conventional ligated brackets under all test conditions and angulations. Also, amplitude of perturbations has a larger role than frequency in reduction of RS values.

No MeSH data available.