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1.
J Prosthet Dent ; 2024 Jul 08.
Artigo em Inglês | MEDLINE | ID: mdl-38981806

RESUMO

STATEMENT OF PROBLEM: The diverse chemical composition of recently introduced resin-modified ceramics complicates the establishment of a universally accepted clinical bonding protocol. PURPOSE: The purpose of this in vitro study was to evaluate the influence of different surface treatments of resin-modified ceramics on the bond strength to a resin cement. MATERIAL AND METHODS: Sixteen 10×12×3-mm resin-modified ceramic slices were obtained from each material (Cerasmart; GC, Shofu Block HC; Shofu, Vita Enamic; Vita, Evolux hybrid; BlueDent, Alium; Alium). Slices were assigned to 4 groups based on surface treatments: Control (no treatment), airborne-particle abrasion with Al2O3 (Al2O3), conditioning with 9% HF (HF), and Al2O3+HF. After treatments and silane coupling agent (Monobond N; Ivoclar) application, 7 resin cement cylinders (Choice 2 veneer; Bisco) were built on each slice and light polymerized for 20 seconds. Half of the specimens (n=14 cylinders) were stored for 24 hours, and the other half were thermocycled (20 000 cycles, 5 °C to 55 °C, 30-second dwell time). Microshear bond strength was tested and analyzed with 3-way ANOVA and the Tukey HSD test (α=.05), and failure patterns were classified. Surface morphology after treatments was observed with scanning electron microscopy and Raman spectroscopy. RESULTS: After 24 hours, all treatments induced higher bond strength (P<.05) than in the control in Evolux. Al2O3+HF caused higher bond strength (P<.05) than in the control in Cerasmart and Shofu, and higher bond strength than Al2O3 in Cerasmart. However, it resulted in lower bond strength (P<.05) than Al2O3 in Alium. After thermocycling, irrespective of the resin-modified ceramic, all treatments induced higher bond strength (P<.05) than in the control. HF induced lower bond strength (P<.05) than Al2O3 in Alium. Al2O3+HF caused the highest bond strength (P<.05) in Evolux and higher bond strength (P<.05) than HF in Vita Enamic. Adhesive failures were prevalent under control conditions, and mixed failures were common after treatments. Al2O3 induced surface alterations in all resin-modified ceramics. HF notably altered Vita Enamic, while it had no noticeable impact on the other resin-modified ceramics. Al2O3+HF caused a considerable alteration in Vita Enamic and modified the other resin-modified ceramics. Vita Enamic had the characteristic vibrational bands of inorganic compounds, while the other resin-modified ceramics exhibited distinct bands associated with organic compounds. CONCLUSIONS: Airborne-particle abrasion with Al2O3 followed by HF yielded the highest bond strength, regardless of the resin-modified ceramic, except for Alium, which demonstrated better bond strength after airborne-particle abrasion with Al2O3. 9% HF for 30 seconds caused notable surface alterations in Vita Enamic, negatively impacting its bond strength. Vita Enamic was the only resin-modified ceramic displaying both organic and inorganic composition, while the other resin-modified ceramics showed predominantly organic composition.

2.
Rev. estomatol. Hered ; 27(3): 176-179, jul.-set. 2017. tab
Artigo em Espanhol | LILACS | ID: biblio-991186

RESUMO

Objetivos: Determinar la presencia y concentración de los metales plomo, cadmio y cromo migrados desde el limpiador lingual "Alitest" en saliva artificial, y estimar la exposición oral a estas sustancias. Material y métodos: Diseño pre-experimental y analítico, para cuantificar las sustancias que son liberadas desde el limpiador lingual al contacto con saliva artificial. Los metales fueron analizados por AAS. Se estimaron los valores de exposición por ingesta oral que fueron comparados con valores de ingesta diaria tolerable para cada grupo etario. Resultados: Se cuantificó la migración de cadmio y cromo en concentraciones promedio de 0.008mg/L y 0.437 mg/L, respectivamente. La concentración de plomo estuvo por debajo de los niveles detectables utilizando el método. A partir de estos valores se estimó la ingesta oral para cada grupo etario y se comparó con el valor provisional de ingesta mensual tolerable (PTMI) o Dosis de Referencia (RfD). Conclusiones: Las sustancias se cuantificaron en concentraciones normales, que no excedieron los valores máximos recomendados.


Objectives: To determine the concentration of heavy metals cadmium and chromium leached from the tongue cleaner "Alitest" into artificial saliva and to assess oral exposure of these substances. Material and methods: Analytical pre-experimental design, to determine the amount of those substances released from the tongue cleaner onto artificial saliva and to quantified them by AAS. Assessment of exposure from oral intake values and comparison with the Provisional Tolerable Monthly Intake (PTMI) or Reference Dose (RfD) values. Results: Cadmium and chromium leachated into artificial saliva were quantified in concentrations of 0.008mg/L and 0.437 mg/L, respectively. Lead concentration was under detectable levels using the method. These values were used to estimate the oral intake for each age group and were compared to PTMI or RfD values. Conclusions: The substances were found in normal concentrations, none exceeding the maximum values of PTMI or RfD.

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