Evaluation of Fracture Resistance of Endodontically Treated Maxillary Central Incisors Restored with Ni-Cr and NPG Casting Post and Core

In modern dentistry, reconstruction of endodontically treated teeth with severely damaged crown structure has always been challenging. The use of post and cores are means to restore teeth after endodontic treatment, and its long-term success has been accepted as the treatment of choice for reconstructing highly damaged teeth. Therefore, the present study was conducted to evaluate the fracture resistance of endodontically treated teeth that have been restored with Nickel-Chromium (Ni-Cr) and Non-Precious Gold Color Alloy (NPG) post and core. Twenty maxillary central teeth were collected, and root canal treatments were performed with the same conditions and equipment for each tooth. Then each tooth was mounted in clear acrylic blocks. After post-space preparation, posts and cores were fabricated using the direct method, then the samples were randomly divided into two groups of 10 samples. (Group One: Ni-Cr posts and cores and Group Two: NPG posts and cores). After preparing the posts and root canal for the post cementation, the Ni-Cr and NPG posts were cemented, and the samples were placed in the simulated condition to the oral environment. Then, a universal testing machine was used to measure the fracture resistance of the restored teeth with static pressure of 0.5 mm/min. T-test analyses and SPSS software was used to compare the mean resistance. Fracture resistance in the Ni-Cr post with an average of 233.8±67.19 was higher than that of the NPG post with an average of 223.0±85.65. However, no significant difference was observed between the two groups (P=0.757). In both groups, most fractures were irreversible, and there was no difference between the two groups in terms of failure type (P=0.871). The fracture resistance of endodontically treated teeth with NPG cast post was not different from that of the endodontically treated teeth with Ni-Cr cast post.