Fracture Resistance of Individually Formed and Prefabricated Fiber Post in Reinforced Structurally Compromised Teeth

Purpose: The purpose of this study was to evaluate the fracture resistance of structurally compromised teeth restored with individually formed and prefabricated fiber post. Material and methods: The coronal part of 60 human extracted intact upper central incisors were removed, and the remaining root received endodontic therapy. Root canal spaces were enlarged to reduce dentin wall thickness to 0.5 to 0.75 mm and post space with 8 mm length. Specimens were divided into control and experimental group (n=30) according to the reinforcement of the root canal dentin with composite resin. Each group was further subdivided according to post type used (n=15): individually formed and ready-made fiber posts. A light-transmitting plastic post was used to create root canal space and to cure the restorative composite resin. Dual-cure resin cement was used for post cementation. Standardized composite resin cores and complete cast crowns were fabricated for the specimen using conventional techniques. Each specimen was then subjected to fracture resistance test in an Instron testing machine with a cross head speed of 0.5 mm/min Data were analyzed with 2-way ANOVA and post-hoc Tukey’s test (α= 0.05) at 5% level of significance. Results: ANOVA results demonstrated a statistically significant difference between root canal reinforcement and fiber post type (P< 0.001); however, the interaction effect was not significantly different (P= 0.435). Individually formed fiber posts with reinforced root canal had higher mean fracture resistance (414.50±22.09 MPa), and the lower mean fracture resistance (372.57±25.66 MPa) was found for ready-made posts in root canal without reinforcement. Conclusions: Structurally compromised teeth behave significantly better when reinforced with an intermediate layer of flowable composite resin and restored with an individually formed fiber post. (1568) Dina M. El-Shokafy, et al. E.D.J. Vol. 68, No. 2