Comparison of fracture resistance of fiber-reinforced post and core with different cementation techniques: in vitro study.

Abstract

The current study aimed to inspect the fracture resistance of fiber post to canal dentin using a different technique of cementation. 60 sound single-rooted central incisors with comparable size and length were stored in normal saline. Each tooth was immersed in 5% sodium hypochlorite (NaOCl). The specimens were randomly divided into 6 groups of 10 specimens each. All included specimens received root canal treatment (RCT). Post-space preparation was done using Gates Glidden drills. Post space was standardized with 10 mm length, keeping 3 to 5 mm as an apical seal. Based on the cementation technique samples were divided into six study groups. Group A: One step-Monoblock; Group B: One step- Monoblock-NA-FP; Group C: One step-Monoblock-RX-MC; Group D: Two-step- RX-MC; Group E: Two-step- RX-FZ; Group F: Two-step- RX-FZ-Custom post. Following cementation, all teeth will be prepared to receive a monolithic zirconia crown with a finish line of 1 mm above the CEJ. Each specimen was mounted in auto-polymerizing clear acrylic resin using a preformed tube. All samples were subjected to pushing forces to measure the fracture strength of the specimen using a universal testing machine. To compare the means among different experimental groups Post Hoc Tukey multiple comparison tests and analysis of variance (ANOVA) were adopted. The highest fracture resistance was observed in group A. Whereas, the lowest fracture resistance was observed in group D samples. Fracture strength in group A samples showed significantly higher fracture resistance values compared to all other groups (p < 0.05). Fracture resistance values in group F specimens were significantly higher than specimens in groups B, C, D, and E respectively (p < 0.05). Monoblock technique using single cementation and core material (Multicore Flow) when polymerized simultaneously exhibited the highest fracture resistance of glass fiber post compared to other cementation techniques.