Fracture resistance of endodontically treated teeth restored with post-core system and endocrown

Mechanical testing of endodontically treated teeth after filling with different coronal restorations is one of the most accepted methods to evaluate the strengthening effect. The aim of the current study was to evaluate the fracture resistance of endodontically treated maxillary premolars restored with either posts-core or endocrown and detect the type of tooth fracture. Forty human bifurcated maxillary premolars were selected for testing after receiving root canal treatment (n=10). The teeth received either composite filling, or post and core or endocrown. Ten intact teeth were tested as a control group. The endocrwon as a coronal restoration. All samples were tested using universal testing machine at speed of 0.5 mm/minute and maximum load at fracture time was measured in Newton (N). The collected data was subjected to analysis using one-way ANOVA and independent sample t-test. The level of significance was set at 0.05. Endocrwon samples significantly exhibited the highest value of load and longest time to fracture (p<0.5) followed by post -core and composite exhibited the lowest value. Most of failure mode of all groups were unfavorable 75.5% of samples. The unfavorable fracture represented 100% of samples in the endocrown group. The fracture in post group was 50%% unfavorable and the fracture in composite group was 60%.In conclusion, Endocrwon as a coronal restoration of endodontically treated maxillary premolar increase the fracture resistance more than post-core or composite.