Discussion
tooth fracture, fatigue, fracture, fractures, tooth
ENDODONTICALLY TREATED TOOTH
The risk of tooth fracture is an undesirable incident usually related to insufficient coronal tooth structure after endodontic treatment [It has been observed that fracture resistance of restoration with a post is directly related to post design, post length, post diameter, core material, and type of cement used [Most in vitro studies of teeth restored with post and core restorations used the fracture resistance test, as it is considered the main recommended characteristic to achieve durable restoration [The crown placement has been questioned as this might obscure the effects of a different post [In addition, in the present study, the groups restored with PEEK post and composite core exhibited less catastrophic fracture, which usually renders the tooth non-restorable and requires extraction. Generally, in both groups, the number of repairable fractures was predominant. The present study’s results are consistent with previous studies [The biocompatible chemical composition and the low surface energy of PEEK materials may lead to difficulties bonding to resin-based materials [This in vitro study had several limitations, making comparing the results with clinical situations difficult. The first limitation concerns that the fatigue test is necessary to determine the long-term survivor of an endodontically treated tooth restored with a post. Another difficulty was encountered in controlling related factors clinically, such as when extracted teeth were used for this study, the potential for significant uncontrollable variations in strength exists, for example, the age of the teeth used in the fracture test, as most of the teeth were extracted in old persons for the periodontal cause. It’s known that the changes in the microstructure of dentin with age cause a degradation in the fatigue and fracture properties [