Oral Function Improves Interfacial Integrity and Sealing Ability Between Conventional Glass Ionomer Cements and Dentin

Abstract

The aim was to investigate if load cycling affects interfacial integrity of glass-ionomer cements bonded to sound or caries-affected dentin. A conventional glass-ionomer, Ketac Bond and a resin-modified glass-ionomer, (Vitrebond Plus), were applied to dentin. Half of the specimens were load cycled. The interfaces were submitted to dye assisted confocal microscopy evaluation. The unloaded specimens of sound and carious dentin were deficiently hybridized when Ketac Bond was used. Ketac Bond samples showed an absorption layer and an adhesive layer that were scarcely affected by fluorescein penetration (nanoleakage), in sound dentin. Nevertheless, a higher degree of micropermeability was found in carious dentin. Load cycling improves sealing capability and remineralization at the cement-dentin interface, as porosity and nanoleakage diminished, in Ketac Bond specimens. In contrast, samples treated with Vitrebond Plus attained a rhodamine B-labeled absorption layer with scarce nanoleakage in both sound and carious unloaded dentin. The adhesive layer was affected by dye sorption throughout the porous cement-dentin interface. Samples treated with Vitrebond Plus had significant increases in nanoleakage and cement-dye sorption after load cycling. With the limitations of an in vitro study, it is expected that conventional glass-ionomers will provide major clinical efficacy when applied to carious-affected or sound dentin.