1 Department of Orthodontics, Dental School, Babol University of Medical Sciences, Iran
Aim: There are currently many patients who need orthodontic treatment. Given the high expense of orthodontic therapy and the fact that orthodontic brackets are recyclable elements, this study was carried out to compare the shear Bond strength of new and recycled brackets in vitro.
materials and Method: Thirty healthy extracted first premolars without cracks or decay were selected. the teeth were randomly assigned to two groups and etched by 37% phosphoric acid for 30 seconds. An icy surface was obtained and brackets (018 standard Dentaurum)were assigned equally to two groups of 15 new and recycled brackets each. After 500 round thermo-cycling in temperatures between 5°C and 55°C, shear bond strength was obtained by dividing the force by bracket cross-sector. The Adhesive Remnant Index (ARI) and the Enamel detachment index (EDI) were evaluated.
Results: Average shear Bond strengths for the new and recycled brackets were 17.5717±7.3929 Mpa and 16.6811±5.3899 Mpa, respectively. There were no significant and differences in Bond strength between two brackets. Furthermore, no significant difference was observed in EDI and ARI ratios.
Conclusion: With respect to shear Bond strength, recycled brackets may be a viable option for fixed orthodontic treatment in clinical practice.