Abstract

FIROOZMAND, Leily M  and  PAGANI, Clóvis. Influence of bleaching treatment on flexural resistance of hybrid materials. Acta odontol. latinoam. [online]. 2009, vol.22, n.2, pp.75-80. ISSN 1852-4834.

The aim of this study is to evaluate the flexural resistance of three types of restorative materials: compomer (Freedom), resin-modified glass-ionomer (Vitremer) and composite resin (Esthet-X), observing whether the application of bleaching agent can cause alterations of their flexural properties. Sixty samples were made using a 10x1x1 mm brass mold, and divided into three groups: G1- Freedom (SDI); G2- Vitremer (3M ESPE); G3- Esthet-X (Dentsply). On half of the samples of each group (10 samples) the bleaching treatment was applied and the other half, used as control, was stored in distilled water at a temperature of 37oC. Whiteness HP Maxx bleaching system was applied on the sample surface following the manufacturer’s recommendations, simulating the bleaching treatment at the clinic. After this period, a flexural strength (three-point bending) test was conducted using (EMIC DL 1000) machine until the samples fractured. The data were submitted to ANOVA and Tukey tests. Of the restorative materials studied, G3- (87.24±31.40MPa) presented the highest flexural strength, followed by G1-(61.67±21.32MPa) and G2-(61.67±21.32MPa). There was a statistical difference in flexural strength after the bleaching treatment. It was concluded that the use of a beaching agent can promote significant alteration of the flexural strength of these restorative materials.

Keywords : Strength; Composite resins; Compomers.

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