Abstract :
Background: Bonded retainers are extensively used after orthodontic treatment to maintain the achieved results. However, bond failure in the retainer system is a frequently observed problem, resulting in the loss of retainer function, leading to relapse.
Objective: The purpose of this in-vitro study was to compare the shear bond strength of different wire-composite combinations.
Materials and Methods: 144 extracted human premolars in pairs were divided into 6 groups of 12 samples each. The orthodontic retainer wires used were Flat woven wire (Leone), Dead soft retention wire (Ortho Classic USA) and two stranded twisted Leone ligature wire (0.018”). The composite that was used was Transbond XT adhesive (3M Unitek) and Enlight Light Cure Adhesive (Ormco). Retainer wires were bonded on the lingual surfaces of the teeth. 72 samples were subjected to debonding with a chisel head in a universal testing machine INSTRON. Comparisons of the means of shear bond strength values were made with one way ANOVA & Tukey’s Post Hoc test.
Results: Maximum shear bond strength was observed in group IA (Leone flat woven wire with Transbond XT). There was a statistically significant difference in the shear bond strength of different retainer wires.
Conclusion: Compared to other wire composite combinations, maximum shear bond strength was observed in Leone flat woven wire with Transbond XT composite. Therefore, it could be the wire-composite combination of choice for the bonded lingual retainer.
Keyword :
Lingual retainer, Bond strength, Adhesive, Universal testing machine