RESUMEN
The effectiveness of commercial and experimental silane coupling agents was evaluated by measuring their shear bond strengths to a ceramic disk. Experimental one-bottle silane coupling agents were prepared using 3-MPTS, 4-META, and resin monomers. The surfaces of two ceramic disks (IPS e-max, Ivoclar Vivadent AG, Schaan, Lichtenstein) were treated by a silane coupling agent to bond them to each other; this bonding was mediated by a commercial flowable resin composite (Clearfil Majesty LV, Kuraray, Tokyo, Japan). A commercial silane coupling agent (Clearfil Porcelain Bond Activator, Kuraray, Tokyo, Japan) modified by adding 4-META exhibited a significantly higher bond strength than the unmodified commercial one-bottle silane coupling agent. Among the tested materials, two experimental one-bottle silane coupling agents composed of 5% 4-META, 45% 3-MPTS, and 50% resin monomers exhibited statistically highest bond strengths.
Asunto(s)
Recubrimiento Dental Adhesivo , Metacrilatos , Cementos de Resina/química , Silanos/química , Bisfenol A Glicidil Metacrilato , Cerámica , Resinas Compuestas , Porcelana Dental/química , Análisis del Estrés Dental , Hidrólisis , Ensayo de Materiales , Polietilenglicoles , Ácidos Polimetacrílicos , Poliuretanos , Resistencia al CorteRESUMEN
Previously, we reported that the integrity of a resin composite restoration deteriorated when the dentin cavity wall was decalcified by conditioning. In this study, to evaluate the bonding between dentin adhesive and non-decalcified dentin surface, we experimented with a novel method of using a high-pressure water spray device to prepare smear layer-free dentin surfaces. When the smear layer was removed, shear bond strength significantly increased regardless of the removal method employed. Further, with glyceryl monomethacrylate (GM) priming, no significant differences in bond strength were observed among these smear layer removal methods: ethylenediamine tetraacetic acid (EDTA) conditioning, phosphoric acid conditioning, and removal by water spray. It was also found that GM priming was key to achieving marginal integrity, whereas contraction gap width increased with phosphoric acid conditioning. It was thus concluded that the efficacy of a dentin adhesive should be evaluated by consistently observing the contraction gap in three-dimensional cavities rather than by mere measurement of bond strength to a flat dentin surface.
Asunto(s)
Recubrimiento Dental Adhesivo , Recubrimientos Dentinarios/química , Dentina/ultraestructura , Grabado Ácido Dental , Quelantes/química , Resinas Compuestas/química , Adaptación Marginal Dental , Análisis del Estrés Dental/instrumentación , Ácido Edético/química , Glicéridos/química , Humanos , Ensayo de Materiales , Metacrilatos/química , Microscopía Electrónica de Rastreo , Ácidos Fosfóricos/química , Presión , Cementos de Resina/química , Resistencia al Corte , Capa de Barro Dentinario , Estrés Mecánico , Propiedades de Superficie , Preparación del Diente/métodos , Agua/químicaRESUMEN
PURPOSE: To evaluate the efficacy of a conventional and newly-developed caries detector (Caries Check) by measuring the Vickers microhardness (VMH) and DIAGNOdent value of the dentin cavity wall of extracted human teeth after removing carious dentin that was stained by the caries detector. METHODS: 30 human teeth with coronal dentin caries extending halfway through the dentin were sectioned and extracted for use in this study. As a control, the longitudinal section of a caries-free extracted human tooth was prepared. The VMH and DIAGNOdent values were measured and the microstructure of the dentin cavity wall was examined using a scanning electron microscope (SEM). RESULTS: When Caries Check was employed as a guide for carious dentin removal, the microhardness of the cavity wall was significantly lower than the normal dentin and the DIAGNOdent value indicated that the dentin may have recalcified. SEM observations of the stained regions revealed that Caries Check did not stain the sclerotic dentin. Based on these findings, Caries Check may be a useful modality because the excavation of the dentin structure was shallower and the sclerotic dentin was preserved.