Intracanal reinforcement with direct composite buildup as an alternative to fiber posts: An in vitro analysis.

Aim: To evaluate and compare the fracture resistance and mode of failure of endodontically treated maxillary central incisors restored using polyethylene fibers (PFs) and short fiber-reinforced composite (SFRC) followed by direct composite restoration.

Settings and design: Academic, in vitro analysis.

Materials and methods: After seeking the approval of the institutional ethics committee, following the inclusion criteria, 66 maxillary central incisors were selected, disinfected, and randomly divided into three groups (n = 22): Group 1 (control group), Group 2 (PF group), and Group 3 (SFRC group). Each group was subdivided into two subgroups (n = 11). Group 1A was the positive control with intact teeth, while Group 1B was the negative control comprising endodontically treated teeth restored with direct composite buildup. Groups 2 and 3 were subdivided based on the fiber extensions, with subgroups 2A and 3A having fibers extended 1 mm above the remaining tooth structure and subgroups 2B and 3B having 3 mm fiber extensions. Except for the intact teeth subgroup (Group 1A), all teeth were sectioned 3 mm above the cementoenamel junction. Standard root canal procedures were performed, and the samples in Groups 2 and 3 were restored using PFs and SFRC, as per their subgroup designation. The restorations were completed without any intraradicular preparation and restored with direct composite buildup. The samples underwent thermocycling to simulate 1 year of clinical function, before being subjected to a fracture resistance test using the Instron universal testing machine. The fracture resistance values and the mode of fracture were recorded and analyzed.

Statistical analysis: Data were analyzed for significance by analysis of variance and Tukey's post hoc test.

Results: The highest mean fracture resistance was observed in the intact teeth group (792.91 MPa), followed by Group 3B (everX flow 3 mm) at 746.27 and Group 2A (Ribbond 1 mm) at 734.09, with no statistically significant differences. While Group 3A (everX flow 1 mm) and Group 2B (Ribbond 3 mm) showed statistically lower fracture resistance values of 599.73 and 546.50, respectively. The lowest mean fracture resistance was recorded in the negative control group (265.54 MPa).

Conclusion: This ultraconservative approach using the two reinforcing fibers that aims to preserve and reinforce the pericervical dentin and restore the remaining tooth structure with direct composite restoration could be a promising treatment option for the rehabilitation of badly mutilated teeth.