Efeito do uso de líquido modelador na estabilidade de cor e translucidez de resina composta

Abstract

One of the greatest challenges in using resin composites relies on the fact that some materials possess stickiness during their clinical application, so that the professionals are using some methods in order to minimize this task, such as the use of flow resins (modeler liquid/LM) to facilitate the modeling of the material in the tooth. However, little is known about the effects of the LM on the optical properties of the restoration. Hence, the aim of this study was to evaluate the effect of diferente modeler liquids on the color and translucency of a resin composite. Twenty-four specimens of the resin composite FiltekTM Z250 (3M ESPE), color shade A1, were prepared (5 mm diameter × 1.5 mm thickness). The specimens were prepared varying the LM type: SBMP – Scotchbond adhesive (3M ESPE); APS – Ambar APS adhesive (FGM); RESILAB – commercial modeler resin (Wilcos); and Control – none LM was used. For the specimens containing LM, it was used to model the resin composite into the mold, where one drop of material was applied together with the resin increment. Light-activation was performed in all specimens for 20 s at the top and bottom surfaces. The specimens were evaluated by means of color and translucency analyses using a digital spectrophotometer (Easyshade; VITA) and the CIEL * a * b * color system. Next, all the specimens were immersed in distilled water for 180 days, with new color and translucency measurements being obtained after 1, 7, 30, 90 and 180 days. Each LM was individually characterized with translucency, refractive index and water contact angle analyses. All data were statistically analyzed using ANOVA and Tukey (α=5%). The translucency of specimens increased significantly after 1 day of water storage for all groups, except SBMP. After 180 days of water storage, all the groups demonstrated translucency values similar to baseline, except Ambar APS group, which kept the more translucent one. The color alteration results demonstrated that after only 1 day of immersion, the control and RESILAB groups had values similar or greater to 3.3 (reference value). After the immersion period, both RESILAB and SBMP showed color alteration similar to each other (p=0.499) and greater than the others (p<0.001). Each LM showed differences regarding their color, translucency, refractive index and hidrophilicity characteristics. In conclusion, modeler liquids may be used during the build-up of resin composite restorations without jeopardizing the optical properties of the restorative material. However, formulations the less hydrophilic as possible should be considered.