Comparative evaluation of frictional forces in active and passive self-ligating brackets with various archwire alloys.
BACKGROUND
Self-ligating brackets are claimed to eliminate or minimize the force of ligation at the bracket-wire interface; therefore, it is imperative to evaluate the frictional features of contemporary self-ligating brackets with different archwire alloys.


METHODS
This in-vitro study compared the effects of stainless steel, nickel-titanium, and beta-titanium archwires on frictional forces of passive and active self-ligating brackets with a conventional bracket. All brackets had 0.022-in slots, and the wires were 0.019 x 0.025 in. Friction was evaluated in a simulated half-arch fixed appliance on a testing machine. The static and kinetic friction data were analyzed with 1-way analysis of variance (ANOVA) and the post-hoc Duncan multiple range test. Archwire alloy and bracket effects were evaluated with 2-way ANOVA.


RESULTS
Static and kinetic frictional forces were lower for both the passive and active designs than for the conventional brackets. Maximum values were seen with the beta-titanium archwires, and significant differences were observed between nickel-titanium and stainless steel archwires. With the passive or active self-ligating brackets, stainless steel wire did not produce a significant difference, but differences were significant with nickel-titanium and beta-titanium wires.


CONCLUSIONS
When nickel-titanium and beta-titanium wires are used for guided tooth movement, passive appliances can minimize frictional resistance.
Krishnan
Manu
M
Army Dental Corps, Indian Army, Pathankot, Punjab, India. manukrishnanin@yahoo.co.in
Kalathil
Sukumaran
S
Abraham
Kurian Mathew
KM
D000704:Analysis of Variance; D003481:Cuspid; D003722:Dental Alloys; D003799:Dental Stress Analysis; D017276:Friction; D006801:Humans; D008422:Materials Testing; D008437:Maxilla; D009532:Nickel; D016382:Orthodontic Appliance Design; D016910:Orthodontic Brackets; D009969:Orthodontic Wires; D013193:Stainless Steel; D014025:Titanium
D003722:Dental Alloys; C023988:beta titanium; C040654:titanium nickelide; D013193:Stainless Steel; D009532:Nickel; D014025:Titanium