Avaliação do efeito do polimento quimico sobre algumas propriedades fisico quimicas das resinas acrilicas ativadas quimica e termicamente




Although chemical polishing of dental acrylic resins have became a very used alternative, very litlle is known about tt:1e effect on the properties of acrylic resin. This study evaluated the effect of this polishing on the residual monomer release in the water, microhardness, transverse resistence and surface texture of heat and a could curing resins, comparing the results obtained with mechanical polishing. The specimens were made and divided into 4 groups: G1- Self-curing resins with mechanical polishing; G2- Self-curing resins with chemical polishing; G3- Heat-curing resins with mechanical polishing; G4- Heat-curing resins with chemical polishing. Afier having undergone to polishing the specimens were imerse on destiled water 37°C and the evaluations were made in 1, 2, 8 and 32 days. Monomers released in the water was evaluated with espectrophotometricaly; the Knoop micro-hardness was measured with Shimadzu a micro-hardness teste r ; the transverse resistance was measured by three points in a EMIC DL a universal machine, following ADA specification n° 12 . According to statistical analysis, it was concluded that : - chemical polishing have significantly increased the amount of residual monomers of both resins in ali periods of time studied and have reduced the superficial hardness of them ali periods; chemical polishing had not interfered on transverse resistance of self-curing and of heat-curing resin. Through evaluation whit SEM it was checked that chemical polishing altered the superficial layer of both resins, promoting a wavy formo


resistencia de materiais materiais dentarios resinas acrilicas dentarias

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