No abstract

This in vitro study aimed to analyze the fracture strength and failure pattern of flared bovine roots restored with different intraradicular fiber posts and core materials, without a ferrule. To conduct this study fifty bovine incisor roots were treated endodontically, and divided into five groups (n=10), according to the following fiber post techniques and core materials: prefabricated fiberglass post and full-body bulk-fill resin composite (PF-BF); prefabricated fiberglass post and dual function resin cement (PF-RC); direct anatomic post and full-body bulk-fill resin composite (AP-BF); CAD-CAM integrated fiberglass post-and-core (CAD-PC); and adjustable fiberglass post and full-body bulk-fill resin composite (AD-BF). Intraradicular fiber posts were cemented with dual functional resin cement (Allcem Core, FGM), restored with CAD-CAM composite crowns (Brava, FGM), and subjected to loading. The data were analyzed by generalized linear models (p <0.05). It was revealed that AP-BF presented lower fracture strength values compared with PF-RC (p=0.006) and AD-BF (p=0.013). Fractures involving the apical third only in CAD-PC. PF-RC presented only failure patterns involving the core restoration or were limited to the cervical third. PF-RC and AD-BF presented higher failure patterns limited to the core restoration, compared with other groups (60% and 50% respectively). Fractures involving the middle third were observed in the PF-BF, AP-BF, CAD-PC, and AD-BF groups. In conclusion, most of the intraradicular fiber post techniques used, and different core materials presented similar fracture strength values. CAD-CAM integrated fiberglass post-and-core presented more fractures involving the middle and apical thirds than the other groups.