Interação de cimentos resinosos e materiais CAD/CAM : resistência de união em dentina

Abstract

The aim of this study was to evaluate the bond strength (μTBS) of novel CAD/CAM restorative materials to different luting cements. Thirty two crowns were milled using CAD/CAM materials (Vita Mark II, Vita Suprinity, Vita Enamic and Lava Ultimate) and luted to sound and fresh cutted dentin using different cements (Relyx ARC, Relyx Unicem 2 and Relyx Ultimate). The specimens were stored in relative humidity of 100% at 37ºC for 24 h and, then sectioned into sticks with water-cooled diamond blade with low-speed cutting saw. The samples (n=16) with cross-sectional areas of approximately 1 mm² were submitted to tensile bond strength test in a universal testing machine with crosshead speed of 0.5 mm/min. The samples were analyzed with SEM to determinate the failure mode. Data were analyzed using 2-way ANOVA and Tukey’s test (α=0,05). Bond strength was significantly affected by the material and interaction between them and luting cements (p=0.001). The μTBS (MPa) values ranged from 12.17 for Vita Mark II with Relyx ARC and 32.93 for Lava Ultimate with Relyx Unicem 2. Considering overall behavior of tested materials Vita Enamic (29.39 MPa) and Lava Ultimate (28.42 MPa) obtained higher μTBS values in comparison to Vita Mark II (14.14 MPa) and Vita Suprinity (14.55 MPa). The μTBS values for Vita Enamic did not differ from those obtained with Lava Ultimate (p=0.845) and the same occurred with Vita Mark II and Vita Suprinity (p=0.986). There was no statistical difference between cements (p=0.176). A promising bonding performance can be achieved with the hybrid CAD/CAM restorative materials to tooth structure and to different types of luting cements after 24h of water storage.