Fracture Resistance of Non-circular Root Canal Teeth Restored with Different Fiber-reinforced Composite Post Systems
Purpose: To compare the fracture resistance and fracture mode of non-circular premolar root canals restored with different fiber-reinforced composite post systems.
Materials and methods: Forty non-circular single premolar root canals were randomly assigned to four groups (n=10). Coronal portions of the teeth were removed at a level 2 mm incisal to the cemento-enamel junction (CEJ). In Group 1 (Var), FibreKleer® posts were cemented with Variolink® II; in Group 2 (Ref), FibreKleer® posts and REFOR-PIN were cemented with Variolink® II; in Group 3 (Mul), FibreKleer® posts were cemented with Multicore® Flow; in Group 4 (Evo), Variolink® II was used for cementation of Evolution posts and cores. Metallic crowns were cemented with Variolink® II in all teeth. The samples were loaded in an Instron® universal testing machine with a crosshead speed of 0.5 mm/min at a 45° angle to the long axis of the tooth. The mean fracture load of each group was analyzed using the one-way ANOVA, Tukey multiple comparison test (p<0.05). The fracture modes of all experimental groups were analyzed.
Results: The mean fracture resistance of the Var group was significantly lower than that of the others (p<0.05). No statistically significant difference was found between the Ref, Mul and Evo groups. Restorable failures were most frequently found in the Ref group (70%).
Conclusions: The use of Multicore® Flow instead of the high thickness of resin cement layer can increase fracture resistance of teeth with non-circular root canals. Fiber-reinforced composite posts and REFORPIN accessory posts or Evolution posts and cores with Variolink® II can be used as an alternative treatment in teeth with non-circular root canals.
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