A comparative study of the physical and elastic properties of new generation elastomeric ligatures with conventional elastomeric ligatures

Abstract

Context: One of the most common methods of securing arch wires to orthodontic brackets is the application of elastomeric ligatures. New generation elastomeric ligatures were introduced to overcome the disadvantages of force decay and staining in conventional ligatures. Aims: The aim was to compare the physical and elastic properties of new generation elastomeric ligatures with the conventional elastomeric ligatures. Materials and Methods: Four groups of clear elastomeric modules (conventional polyurethane based modules, latex free elastomeric modules, alastik easy to tie modules, silver and silicone impregnated super ligatures) were tested for tensile properties, frictional resistance, and color stability in as received condition and following 1-week, 2 weeks, and 1-month of intra-oral exposure. A universal testing machine was used for testing tensile properties. The color stability was tested by measuring the color change using scanned images of the modules at different time periods. Statistical Analysis: Two-way ANOVA, post-hoc multiple comparisons Bonferroni-Dunn test and the paired t-test were used. Results: The alastik group showed the highest mean tensile strength and super ligatures showed the lowest tensile strength values. There was a statistically significant decrease in the mean tensile strength in all groups following intra-oral exposure (P < 0.05). The super ligatures showed the lowest mean frictional resistance and latex free group showed the highest mean frictional resistance values. The color change following intra-oral exposure was significant in all the groups (P < 0.05) with the change being the highest in super ligatures group and the least in alastik group. Conclusions: There are significant differences in physical and elastic properties of different brands of ligatures, which should be considered during the selection of these products.

Keywords

• Colour stability
• elastomeric modules
• frictional resistance
• tensile properties