Comparison of the shear Bond strength between new and recycled brackets: An in vitro study

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 ۳۷% phosphoric acid for ۳۰ seconds. An icy surface was obtained and brackets (۰۱۸ standard Dentaurum)were assigned equally to two groups of ۱۵ new and recycled brackets each. After ۵۰۰ round thermo-cycling in temperatures between ۵°C and ۵۵°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 ۱۷.۵۷۱۷±۷.۳۹۲۹ Mpa and ۱۶.۶۸۱۱±۵.۳۸۹۹ 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.

Keywords:

Recycled brackets , Shear Bond Strength , fixed orthodontic