Abstract:

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.Methods :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°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 cmPmin. Analysis of variance followed by the Newman- Keuls pairwise multiple comparison test was used to compare the results of the groups tested. Results :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 sig2  nificant difference between each other. There was a statistically significant difference between the fracture resistance of Celay postcore restored teeth with and without 2. 0 mm dentine ferrule.Conclusion :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.

Key words: full ceramic, post and core , endodontically treated teeth