In vitro evaluation of the frictional forces between brackets and archwire with three passive self-ligating brackets.
The aim of this in vitro study was to evaluate the frictional forces between bracket and archwire that included three passive self-ligating brackets (Damon SL2 SDS). The brackets were individually bonded to a brass mount using a preformed 0.021 x 0.025 inch stainless steel wire jig in order to exclude adverse tipping or torsion. The central bracket was positioned 1 mm higher than the others, in order that the three brackets were vertically unaligned. Thirty-six similar set-ups including in total 108 brackets were investigated using the same wire: copper (nickel-titanium) 0.014 inches. A testing machine was designed and constructed to measure the frictional forces between the wire and the three-bracket set-up. Twelve set-ups were tested to measure kinetic frictional forces between the wire and unaligned passive self-ligating brackets used in the closed position. The frictional properties of two sets of 12 three-bracket set-ups (control) were tested and measured with an open slide and conventional ligation. A stainless steel ligature wire was used in the former, while elastomeric modules were employed in the latter. One-way analysis of variance showed a significant effect of ligation mode on the frictional properties of the three-bracket set-ups (P < 0.001). Post hoc pairwise comparison showed that the frictional forces arising from passive self-ligation were significantly lower (P < 0.01) than those resulting from elastic ligation. The same result was achieved when comparing self-ligation and metallic ligation (P < 0.01). No significant difference was found when comparing elastic and metallic ligation.
Department of Orthodontics, University of Messina, Italy.
Giancarlo
G
Cordasco
Giampietro
G
Farronato
Felice
F
Festa
Riccardo
R
Nucera
Elena
E
Parazzoli
Giovanni Battista
GB
Grossi
D003300:Copper; D003722:Dental Alloys; D003799:Dental Stress Analysis; D020724:Elastomers; D017276:Friction; D009532:Nickel; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D013193:Stainless Steel; D014025:Titanium
C415948:Copper NiTi; D003722:Dental Alloys; D020724:Elastomers; D013193:Stainless Steel; D003300:Copper; D009532:Nickel; D014025:Titanium