Sliding resistance with esthetic ligatures: An in-vitro study

Introduction: This study was developed to evaluate in vitro the properties related to sliding resistance of esthetic ligatures. Methods: Frictional force of 6 ligatures-2 conventional, 2 specially coated elastomeric, Teflon-coated (Dupont, Wilmington, Del) stainless steel, and stainless steel (control) ligatures-were studied by sliding 0.019 x 0.025-in stainless steel wire through the 0.22-in slot of stainless steel bracket. Elastomeric ligatures were tested for frictional and tensile forces under 3 experimental conditions: recent stretching, after 21 days of simulated stretching in artificial saliva, and a demineralizing/remineralizing regimen. Statistical analysis was conducted with ANOVA and Games-Howell tests. Results: There was high correlation between frictional and tensile forces of elastomeric ligatures, with reduction of both after 21 days. The demineralizing/remineralizing regimen reduced the frictional forces of ligatures to the same level as the ligatures in artificial saliva. Teflon-coated and stainless steel ligatures showed the lowest initial frictional forces, but there was no difference in friction of stainless steel and poststretched elastomeric ligatures. Conclusions: Frictional forces generated by esthetic elastomeric ligatures under simulated oral environments are not stable and are more related to tensile force than to surface characteristics of the ligatures.