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.

The effect of dentine pre-treatment using bioglass and/or polyacrylic acid on the interfacial characteristics of resin-modified glass ionomer cements

“…Nevertheless, the current study showed a slight, but nonsignificant increase of bond strength values along with reduction of interfacial nanoleakage, in those specimens created with application of the RMGIC on BAG air-abraded dentine. It is believed that load cycling may have contributed to enhance the bioactive synergic effect of BAG and the RMGIC, which protected and remineralised the bonded-dentine interface due to mineral crystallites remaining within the collagen after partial demineralisation, acting as seed sites for apatite growth 48,49 . Indeed, Toledano at al., 33 showed that mechanical loading may promote dentine mineralisation at 24h and 21 days of storage in distilled water, with increase of the mineral-matrix ratio, lack of nanoleakage and permeability at the resin-dentine interface of specimens created through self-etching and EDTAconditioned bonding approaches.…”

The forgotten merits of GIC restorations: a systematic review

“…It comprises an intermediate layer between the GIC and the tooth substrate. In 10 studies that showed this interphase layer, the time for the formation was 1 to 10 days of contact between GIC and tooth substrates [44,45,55,62,67,68,71,72,75,76]. It develops due to chemical interaction between the filling and tooth.…”

“…Five of them used Yes (6) Yes, No (7) C, M (8) No fluorescence staining with rhodamine B [44,45,68,69,72], and two of them used time lapse imaging to observe cement luting, dehydration, and rehydration [58,73]. Two reports from the same research group looked at the effects of mechanical loading on the GIC-dentine attachment [45,72]. Sidhu et al [69] used real-time imaging of a shear test to examine GIC failure modes, which was 100% cohesive.…”

“…An interaction interphase layer is formed and seen when GIC comes into contact with pretreated dentine [45,55,67,68,71,75,76]. It has been proposed that such pretreatment exposes collagen and facilitates diffusion of GIC into the porous demineralized substrate [72]. That may be a reason why many studies pretreated dentine, although GIC is self-etching and may not require pretreatment to form a sound interface with the tooth substrates.…”

“…Following GIC application, the interphase layer appears after 1-10 days [44,45,55,62,67,68,71,72,75,76]. Two studies claim that the interphase layer contains elements originating from both GIC and the tooth substrates, basing this conclusion on evidence as presented by transmission electron microscopy and Raman spectroscopy [44,71].…”