Avaliação qualitativa e da resistência à flexão biaxial em materiais cerâmicos reforçados, submetidos a diferentes tratamentos de superfície

Abstract

The present work had as objective to evaluate the influence of the surface treatment on the resistance to biaxial flexion of reinforced ceramics, submitted to mechanical fatigue stress. Samples were obtained in disk format of 12 mm diameter by 1.2 mm thickness from lithium disilicate ceramic blocks (IPS e.max CAD, ivoclar-vivadent) and lithium silicate ceramics reinforced by zirconium (Suprinity, VITA, Celtra Duo, DENTSPLY). Five groups were defined, one being the control group (C, n = 15), where the test subjects did not receive surface treatment and the four groups with surface treatment, being (n = 15): Hydrofluoric acid 10% and silane (HF); Blasting with 50μm aluminum oxide and silane (O); Blasting with Rocatec® 30μm and silane (R); and application of Monobond Etch & Prime (M). In addition, three samples were included in each group for the purpose of complementary qualitative analyzes. The IPS.emax CAD (E), Suprinity (S) and Celtra Duo (L) groups received the resinous cement Relyx u200 (3M ESPE) after each surface treatment and were submitted to the mechanical cycling test for 1.0x106 cycles and after biaxial bending test (ISO 6872) immersed in water. The samples designated the qualitative analyzes were submitted to optical profilometry, scanning electron microscopy (SEM) and dispersive energy spectrometry (EDS). The data obtained in this study were submitted to the statistical analysis of variance model (ANOVA) and to the multiple comparison test of Tukey. The tests showed a statistically significant difference in biaxial flexural strength in all ceramic materials used (P <0.05) and surface roughness of all materials. Thus, it is concluded that the surface treatment changes the roughness of all the ceramics involved, the biaxial flexion was altered in face of the surface treatment used in each ceramic material and for all the reinforced ceramic materials involved, despite the different chemical composition, the surface treatment in which the highest biaxial flexural strength results were obtained were the HF and M groups.