The Repair Bond Strength of Resin Modified Glass Ionomer After Different Surface Treatments and Time Lapsed

Abstract

This study was carried out to evaluate the tensile repair bond strength of immediate repair of self cured RMGI with different surface conditions and time lapsed. Ten whole hourglass slabs, to serve as a control, and 80 half-slabs from RMGI were made in an especially designed split copper mold. After different time lapsed, the half-slabs from each type of RMGI were divided into eight groups according to the repair protocol and time lapsed. Fresh mix of RMGI was used for the repair of RMGI in this study. Repair tensile bond strength was evaluated using a universal testing machine at crosshead speed 0.5mm/min. Data was collected and analyzed using SPSS version 17.0. Fractured surfaces were examined using digital-microscope at X50 magnification. The results showed that the different surface treatment of RMGI, the time lapsed, and their interactions had a statistically significant effect on the tensile repair bond strength. Under the limitations of this study, several conclusions can be drawn: 1- Time factor seems to be an important factor for tensile bond strength of the RMGI. 2- The surface treatment of RMGI directly affects the tensile bond strength. 3- Immediate mechanical interference with RMGI; grinding decrease the tensile bond strength.