RESUMEN

OBJECTIVE: The objective of this study was to analyze the microstructure and crystalline structures of ProRoot MTA, Biodentine, CEM Cement, and Retro MTA when exposed to phosphate-buffered saline, butyric acid, and blood. METHODS AND MATERIALS: Mixed samples of ProRoot MTA, Biodentine, CEM Cement, and Retro MTA were exposed to either phosphate-buffered saline, butyric acid, or blood. Scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopic (EDX) evaluations were conducted of specimens. X-ray diffraction (XRD) analysis was also performed for both hydrated and powder forms of evaluated calcium silicate cements. RESULTS: The peak of tricalcium silicate and dicalcium silicate detected in all hydrated cements was smaller than that seen in their unhydrated powders. The peak of calcium hydroxide (Ca(OH)2) in blood- and acid-exposed ProRoot MTA, CEM Cement, and Retro MTA specimens were smaller than that of specimens exposed to PBS. The peak of Ca(OH)2 seen in Biodentine™ specimens exposed to blood was similar to that of PBS-exposed specimens. On the other hand, those exposed to acid exhibited smaller peaks of Ca(OH)2. CONCLUSION: Exposure to blood or acidic pH decreased Ca(OH)2 crystalline formation in ProRoot MTA, CEM Cement and Retro MTA. However, a decrease in Ca(OH)2 was only seen when Biodentine™ exposed to acid. CLINICAL RELEVANCE: The formation of Ca(OH)2 which influences the biological properties of calcium silicate cements was impaired by blood and acid exposures in ProRoot MTA, CEM Cement, and Retro MTA; however, in the case of Biodentine, only exposure to acid had this detrimental effect.

Asunto(s)

Compuestos de Calcio/química , Cementos Dentales/química , Silicatos/química , Sangre , Ácido Butírico , Combinación de Medicamentos , Concentración de Iones de Hidrógeno , Ensayo de Materiales , Microscopía Electrónica de Rastreo , Óxidos/química , Compuestos de Fósforo/química , Materiales de Obturación del Conducto Radicular/química , Solución Salina , Espectrometría por Rayos X , Propiedades de Superficie , Difracción de Rayos X

RESUMEN

OBJECTIVE: This study evaluated the effect of saliva contamination during bonding procedures without removing saliva on shear dentin bond strength of three adhesive generations when rubber dam isolation is not feasible. MATERIALS AND METHODS: Flat superficial dentin surfaces of seventy-two extracted human molars were randomly divided into three groups (A: Scotch Bond MP Plus (SBMP), B: Single Bond (SB), C: Prompt L-Pop) according to the applied adhesives and twelve subgroups (n=6) according to the following saliva contamination applied in different bonding steps. The specimens were contaminated with saliva after etching (A1 and B1), after primer application (A2), after adhesive application before polymerization (A3, B2 and C1), and after adhesive polymerization (A4, B3 and C2). Three subgroups were not contaminated as controls (A5, B4 and C3). Resin composite was placed on dentin subsequently followed by thermocycling. Shear test was performed by Universal testing machine at 0.5 mm/min crosshead speed. The collected data were statically analyzed using one and two-way ANOVA and Tukey HSD. RESULTS: In contrast to SBMP and SB, the mean shear bond strength of Promote L-Pop was not significantly different between contaminated and uncontaminated subgroups. Mean shear bond strengths of SBMP subgroups contaminated after adhesive polymerization or uncontaminated were significantly higher compared to the other two groups (p<0.05). CONCLUSION: Unlike Promote L-Pop, saliva contamination could reduce shear bond strength of the total-etch adhesives. Furthermore, the step of bonding procedures and the type of adhesive seems to be effective on the bond strength of adhesive contaminated with saliva.