CAD/CAM post-and-core using different esthetic materials: Fracture resistance and bond strengths

摘要

Purpose: To evaluate the fracture resistance (FR), and push-out bond strengths (BS) of custom-made CAD/CAM post-and-cores manufactured with different esthetic materials. Methods: 90 single-rooted extracted teeth were selected, endodontically treated and prepared to receive the posts. The specimens were randomly divided into three equal groups according to the material: hybrid ceramic Vita Enamic (HC); nano-ceramic resin composite Lava Ultimate (RC); and experimental epoxy-resin reinforced by glass-fiber (FG). The post-and-cores were manufactured using CAD/CAM and cemented using a self-adhesive resin cement (Rely X Unicem2). A subgroup of 30 specimens (n=10) was subjected to fatigue (1,000,000 cycles at 5 Hz) and then to the FR test. Another subgroup with 60 specimens was submitted to the BS test, with and without fatigue. Data were submitted to analysis of variance (FR - one-way ANOVA; BS - two-way ANOVA) and Tukey's test (alpha = 0.05). Results: The FR values (mean SD, in Newtons) were 414.5 +/- 83.9 (HC), 621.3 +/- 100.3 (RC), and 407.6 +/- 109.0 (FG), with RC showing significantly higher FR values (P 0.05). For BS, there was no statistically significant difference among the materials, with and without fatigue (P 0.05). The type of material used to obtain the CAD/CAM-customized post-and-cores had a significant effect on the FR, but not on the BS of the specimens. Fatigue did not influence the BS for the tested materials.