Results
fracture
The results of the pullout and fracture strength tests were not statistically significant (p > 0.05) using the Shapiro–Wilk test, meaning that the data does not differ significantly from the normally distributed. However, the mean values of fracture resistance were significantly different among tested posts (p = 0.013), with the highest mean fracture resistance (416 ± 49 N) of Group P1 (Table 
Comparison of the mean fracture resistance between the tested groups*: Significant difference using t-test, C1: Custom-made post-core of PEEK; P1: Prefabricated PEEK post and composite coreThere was a significant difference in the failure modes using the Pearson Chi-square test (p = 0.16) between the studied groups (Fig. 
The bar chart chows the distribution of the fracture type among the tested groups. The bars displayed standard errors
Types of fracture modes under stereomicroscope. Core fracture (
Comparison of the mean pullout resistance between the tested groups*: Significant difference using t-test, C2: Custom-made post-core of PEEK; P2: Prefabricated PEEK post and composite core