In vitro mechanical stimulation facilitates stress dissipation and sealing ability at the conventional glass ionomer cement-dentin interface.
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AuthorToledano Pérez, Manuel; Osorio Ruiz, Raquel; Osorio Ruiz, María Estrella; Cabello Malagón, Inmaculada; Toledano Osorio, Manuel; Sánchez Aguilera, Fátima
Toledano M, Osorio R, Osorio E, Cabello I, Toledano-Osorio M, Aguilera FS. In vitro mechanical stimulation facilitates stress dissipation and sealing ability at the conventional glass ionomer cement-dentin interface. J Dent. 2018 Apr 10. pii: S0300-5712(18)30075-7. doi: 10.1016/j.jdent.2018.04.006. [Epub ahead of print] PubMed PMID: 29653140. [http://hdl.handle.net/10481/50516]
SponsorshipThis work was supported by the Ministry of Economy and Competitiveness (MINECO) and European Regional Development Fund (FEDER) [Project MAT2017-85999-P].
Objective: The aim of this study was to evaluate the induced changes in the chemical and mechanical performance at the glass-ionomer cement-dentin interface after mechanical load application. Methods: A conventional glass-ionomer cement (GIC) (Ketac Bond), and a resin-modified glass-ionomer cement (RMGIC) (Vitrebond Plus) were used. Bonded interfaces were stored in simulated body fluid, and then tested or submitted to the mechanical loading challenge. Different loading waveforms were applied: No cycling, 24 h cycled in sine or loaded in sustained hold waveforms. The cement-dentin interface was evaluated using a nano-dynamic mechanical analysis, estimating the complex modulus and tan δ. Atomic Force Microscopy (AFM) imaging, Raman analysis and dye assisted confocal microscopy evaluation (CLSM) were also performed. Results: The complex modulus was lower and tan delta was higher at interfaces promoted with the GIC if compared to the RMGIC unloaded. The conventional GIC attained evident reduction of nanoleakage. Mechanical loading favored remineralization and promoted higher complex modulus and lower tan delta values at interfaces with RMGIC, where porosity, micropermeability and nanoleakage were more abundant. Conclusions: Mechanical stimuli diminished the resistance to deformation and increased the stored energy at the GIC-dentin interface. The conventional GIC induced less porosity and nanoleakage than RMGIC. The RMGIC increased nanoleakage at the porous interface, and dye sorption appeared within the cement. Both cements created amorphous and crystalline apatites at the interface depending on the type of mechanical loading.