I fabricated composite resin cores using fiber posts (Snowpost; Carbotech Co., Lewis Center, OH, USA) and prefabricated metal posts (AD Post; Kurary Co., Tokyo, Japan), and compared the fracture resistance and the type of fracture of posts and cores cemented in the abutment tooth. Post canals were created in maxillary lateral incisor roots in preparation for receiving a crown. A fiber or prefabricated metal post was bonded to the root canal with resin cement (Panavia Fluoro Cement; Kurary), and composite resin cores were fabricated by the direct technique. In addition, post-cores fabricated by the indirect method using a fiber post and hybrid-type composite resin were also bonded to root canals using adhesive resin cement. All samples were loaded at an inclination of 45 degrees with the vertical axis to assess fracture resistance.
The combination of a prefabricated metal post with composite resin exhibited the greatest fracture resistance (88.1kgf), the combination of a fiber post and composite resin core showed the lowest resistance (62.7kgf), and the post and core fabricated using a fiber post and hybrid-type composite resin with the indirect method had a fracture resistance of 68.8kgf. The t-test identified a significant difference in fracture resistance between the fiber and metal posts. Moreover, in the fiber post group, the post core was displaced without fracturing the root, while the metal post caused root fracture on the side opposite that of loading.