Effect of different ferrule designs on the fracture resistance and failure pattern of endodontically ceramic crowns

www.scielo.br/jaos O This study investigated the effect of different ferrule heights on endodontically ! ! "# Ivoclar-Vivadent) luted with self-polymerized resin cement (Multilink, Ivoclar Vivadent) while the coronal section was restored with hybrid composite core build-up material (Tetric Ceram, Ivoclar-Vivadent), which received all-ceramic crown. Different ferrule heights were investigated: 1-mm circumferential ferrule without post and core (group 1 used as control), a circumferential 1-mm ferrule (group 2), non-uniform ferrule 2-mm buccally and 1-mm lingually (group 3), non-uniform ferrule 3-mm buccally and 2-mm lingually (group 4), and $ %& ' groups were investigated by applying axial load to the ceramic crowns (n=10). Data were analyzed statistically by one-way ANOVA and Tukey’s post-hoc test was used for pair-wise comparisons ( *+ +%& ' $ $ load of all tested groups (P<0.780). The control group had the lowest fracture resistance (891.43±202.22 N) and the highest catastrophic failure rate (P<0.05). Compared to the $ / $ $ $ 6 specimens. Conclusions: Within the limitations of this study, increasing the ferrule length 6 $ ; $ of these restorations under function.