Evaluation of mechanical properties of different polyetheretherketone endodontic post systems: an in vitro study

BACKGROUND: Survival of endodontically treated teeth depends on an efficient restoration of the missing tooth structure. OBJECTIVES: This study aimed to investigate the mechanical properties of different endodontic post systems. MATERIALS AND METHODS: Human permanent maxillary central incisors (no.=58) were decoronated and root-filled. The specimens with prepared root canals were randomly divided into Group P: Polyether Ether Ketone (PEEK) post and composite core and Group C: custom-made post-core of PEEK. The cementation of the posts was carried out using self-adhesive resin cement. Nano-hybrid composite resin was used for core fabrication. After cementation, the specimens from each group were randomly divided into two subgroups according to the types of tests utilized: 14 from each group were for the fracture strength test, which was restored with IPS e-max CAD crown, and 15 from each group for the pullout resistance test. A universal testing machine was used for the test performance. RESULTS: The fracture resistance test showed that the values significantly differed among tested posts (P = 0.013). Group P showed the highest fracture resistance. Group C exhibited higher mean pullout resistance values than the other group (P) (P = 0.059). In the two-piece PEEK post and composite core, the predominant type of failure was a core fracture, while in the one-piece PEEK post-core, most types of failures were either in the crown or in the post. CONCLUSIONS: The prefabricated posts are more resistant to fracture than the custom-made posts, with fracture and displacement mainly of the core. In contrast, both showed similar pullout resistance.