Shear Bond Strength of Low Shrinkage Resin Composite to Resin Modified and Nano-Filled Glass Ionomer Cements

Abstract

Objective: This study was designed to assess the shear bond strength between low shrinkage composite to resin-modified and nanofilled glass ionomer cements using different rotary instruments to finish the surface of glass ionomer cements. Materials and Methods: Sixty standardized cylindrical glass ionomer specimens were prepared using a split Teflon mold. They were divided into two main groups (30 specimens each), according to the type of the glass ionomer used (Vitremer RMGI and N100 nanofilled GI). Each group was further subdivided into three subgroups (10 specimens each) according to their surface finish, either cured against mylar strip, finishing the surface with carbide bur and diamond stone. Then they were bonded to low shrinkage resin composite (Feltic P90). The specimens were subjected to shear bond strength testing. The data were collected, tabulated and statistically analyzed. Results: Both carbide bur and diamond stone had statistically significant higher shear bond strength compared to specimens cured against the mylar strip. Statistically significant higher shear bond strength values were recorded with Vitremer RMGI finished with carbide and N100 nanofilled GI finished with diamond stone. Conclusions: RMGI finished with carbide bur and nanofilled GI finished with diamond stone as a base under low shrinkage composite provided the highest shear bond strength results.