Influence of intracoronal bleaching agents on the bond strength of MTA cements to composite resin and their surface morphology

Abstract

The objective of the present in vitro study was to evaluate micro-tensile bond strength (µSBS) of MTA cements to composite resin using a universal adhesive after internal bleaching procedure, and to examine surface characteristics of MTA cements exposed to bleaching agents. MTA specimens were divided into three subgroups according to the bleaching agent used which were, 37% carbamide peroxide (CP), 35% hydrogen peroxide (HP), and no exposure as a control group (n = 12). After exposure to bleaching agent, composite resins were applied to MTA surfaces using a universal adhesive in self-etch mode. The specimens were exposed to a shear force until failure to evaluate bond strength. MTA surfaces were investigated using scanning electron microscopy (SEM) to observe the effects of the bleaching agents. Differences between groups were analyzed using two-way ANOVA test and intergroup comparisons were assessed with Tukey test (p < 0.05). Although there was a slight difference in bond strength between bleaching agents (CP and HP), no significant difference was found, irrespective of MTA cement. After the HP application, the bond strength values decreased approximately by half compared with the controls. SEM results demonstrated distinct morphological differences between the intact MTA surface (control) and treated MTA surface. Distinct micro-cracks, surface irregularities, and capillary voids formed due to the superficial dissolution caused by peroxides. Exposure to the intra-coronal bleaching agents had a negative influence on the surface morphology of MTA cements and their bond strength to composite resin. KeywordsAdhesion • Bond strength • Intra-orifice barrier • Intra-coronal bleaching agents • Mineral trioxide aggregate * S. Sismanoglu

Shear bond strength of calcium silicate-based cements to glass ionomers

“…To minimize microleakage beneath composite resin restorations, the use of glass ionomer cement or resin-modified glass ionomer cement as bases has frequently been suggested [ 13 ]. A review of the literature pertaining to the SBS of calcium silicate-based materials revealed that the majority of studies have focused on WMTA [ 4 , 14 – 17 ], with limited investigations conducted on MMTA and MPPC [ 18 ]. The objective of our research was to compare the SBS of WMTA, MMTA, and MPPC-calcium silicate-based biomaterials commonly employed in VPT with those of various restorative materials (EFHF, FIILC, and ABR).…”