Force system produced by different cross-sections of a tloop orthodontic spring: an analysis by the finite element method

Abstract

The use of orthodontic retraction springs for the correction of dental positions has been very efficient over the years, especially T-loop orthodontic springs. These springs are made with metallic wires of various cross-sections and alloys. The present study mains to analyze the influence of different cross-sections of wires in the dental movement, with the use of T-loop geometry of titanium-molybdenum (TiMo alloy). The device was modeled three-dimensional and simulations were carried out by the finite element method for large displacements. It has been observed that there is an increase in the values of forces and moments, as well as in the stiffness of the spring, with the increase of the cross-section of the wire. Regarding tooth movement, no significant difference was observed in cross-sections because the moment/force ratio (M/F) remained practically unchanged. The study also pointed out that there are restrictions in the use of some cross-sections in certain activation values, since the forces magnitudes are outside the zone of ideal orthodontic forces used clinically.