COMPARISON OF THE SHEAR BOND STRENGTH OF REBONDED
MECHANICALLY RETENTIVE CERAMIC BRACKETS WHICH
WERE CLEANED BY TWO DIFFERENT METHODS
drg. L. CINTHIA HUTOMO, Sp Ort
ABSTRACT
The purpose of this study was to measure the shear bond strength of rebounded mechanically retentive ceramic brackets prior which the base of them were cleaned by two different methods. The first method was burnt out using spirituous lamp, and the second method was burnt out using spirituous lamp and sandblasted for 4 second eventually.
Thirty debonded ceramic brackets were prepared as the subject of this study. They were devided into two groups namely A and B which contains fifteen debonded brackets each. Group A was used to determine shear bond strength of rebonded ceramic bracket which was cleaned by first method and group B was used to determine shear bond strength of rebonded ceramic bracket which was cleaned by second method. The ceramic bracket which have been cleaned were rebonded on a good extracted permanent human upper first premolar.
The shear bond strength were measured by Panke Pearson Equipment Limited, whereas the bond failure location of the rebonded brackets were examined using Zoom Stereo Microscope. T test used to compare of the shear bond strength between two groups, whereas Chi-Square analysis was used to determine the bond failure location of rebounded ceramic brackets.
The result of this experiment showed that shear bond strength of rebonded ceramic brackets which were cleaned by second method was higher than those by first menthod, and had significant differences ( p<0,01 ). Although the bond strength of rebounded ceramic brackets which were cleaned by first method was lower than the ones using second method, they were still above the clinical standard for intra oral retention. The bond failure location of rebounded ceramic brackets both by first method and second method after shear bond strength were test, show no significant differences ( p>0,05 ). The bond failure location of rebounded mechanically retentive ceramic brackets which cleaned by method I were mostly happen in the adhesive ( 86,7%), and on the method II all the failure happen in the adhesive ( 100% ).
