Shear Bond Strenght Evaluation of Recycled or Rebonded Brackets

Sérgio Milton Martins de Oliveira PENIDO, Joel Cláudio da Rosa MARTINS, Ary dos Santos PINTO, Maurício T. SAKIMA

Recycling debonded brackets has been a proper alternative for reducing costs in orthodontic practice. Some methods applied to the brackets recycling are: 1) application of heat to burn the adhesive; 2) use of chemical solvents to corrode the adhesive; 3) sandblasting of aluminum oxide particles (micro etching); 4) removing of resin using a carborundum mounted bur. It was utilized 40 human premolars. Orthodontic brackets were bonded on each tooth using Concise. The samples Concise were divided into 4 groups and submitted to shear bond strength tests at the speed of 0.5 mm/minute. In group I (control) the brackets were kept in place up until the mechanical testing time. In groups II, III and IV the brackets were debonded and the enamel surfaces were cleaned. In groups II and III the same brackets were rebonded after being recycled by aluminum oxide (90 mmm) sandblasting and by carborundum mounted bur removing of the remaining composite. New orthodontic brackets were rebonded on teeth in group IV. The results were submited to a multivariate analysis with a level of significance of 1%. The additional test was defined by the analysis of the confidence intervals of 95%. It was concluded that: Shear bond strength of recycled brackets by aluminum oxide sandblasting was similar to the control group, and higher than those recycled by carborundum mounted bur.

Keywords: Recycled brackets. Aluminum oxide.

Sunday, May 05, 2024 11:23