[Fracture strength of custom-fabricated celay all-ceramic post and core]

The purpose of this study is to compare the fracture strengths of custom-fabricated Celay all-ceramic post-core, custom cast metal post-core, and prefabricated stainless steel post (Parapost) plus composite resin core with or without a 2.0 mm dentine ferrule.

A total of 60 recently extracted human maxillary central incisors were endodontically treated and divided into five groups of 12. They were given the following treatments: Group A: Celay ceramic post-core with 2.0 mm dentine ferrule, Group B: Celay ceramic post-core with no dentine ferrule, Group C: cast metal post-core with 2.0 mm dentine ferrule, Group D: cast metal post-core with no dentine ferrule, and Group E: prefabricated post and composite core with 2.0 mm dentine ferrule. All specimens were stored at 100% humidity at room temperature for 30 days before testing. Each specimen was in a special jig at a 45 degrees angle to the long axis and subjected to a load on MTS 810 universal material testing machine until failure, with crosshead speed of 0.02 cm/min. Analysis of variance followed by the Newman-Keuls pairwise multiple comparison test was used to compare the results of the groups tested.

There was a statistically significant difference between five groups (P < 0.01). Celay ceramic post-core with 2.0 mm dentine ferrule (758.35 N +/- 119.26 N) and cast metal post-core with 2.0 mm dentine ferrule (756.63 N +/- 166.22 N) had a significantly larger mean failure threshold for fracture than the other three groups which had no significant difference between each other. There was a statistically significant difference between the fracture resistance of Celay post-core restored teeth with and without 2.0 mm dentine ferrule.

The custom-fabricated Celay post-core could be a choice for clinical use in endodontically treated tooth when the final restoration is an all-ceramic crown and the preparation has a 2.0 mm dentine ferrule.