Biomechanical evaluation of horizontal intracoronal reinforcement strategies in endodontically treated teeth: An in vitro study

Context: Comparison of reinforcement strategies for root-filled teeth. Aim: Comparative evaluation of four conservative intracoronal reinforcement techniques on the fracture resistance and compressive stress of root canal-treated premolars. Settings and Design: Recently extracted human upper premolars were randomly divided into five groups ( n = 10): intact teeth (control), horizontal fiber-reinforced composite (FRC) post, horizontal dentin post, polyethylene fiber reinforcement (Ribbond), and pre-impregnated glass fiber reinforcement (Interlig). Excluding the control group, mesio-occluso-distal cavities were prepared in the other groups, root canals were treated, reinforcement was performed according to the assigned techniques, and restoration was done with bulk-fill composite resin. Fracture resistance and compressive stress were measured using a universal testing machine after thermocycling. Statistical Analysis Used: Fracture resistance and compressive stress were analyzed using one-way analysis of variance (ANOVA) and Tukey’s post hoc test (α =0.05). Results: Significant differences were found between the groups ( P = 0.008). The control and pre-impregnated glass fiber groups showed the highest and similar values of compressive stress. The horizontal FRC post group showed the lowest values, which were significantly inferior ( P < 0.05). The horizontal dentin post and polyethylene fiber groups performed better than the horizontal FRC post group. Conclusions: Pre-impregnated glass fiber, horizontal dentin post, and polyethylene fiber reinforcement exhibited biomechanical performance equivalent to intact teeth, while horizontal FRC posts demonstrated inferior performance.