Evaluation of the Fracture Resistance of Endodontically Treated Teeth Restored with Ribbon Fibers (an in vitro study)

The aim of this study was to evaluate the fracture resistance of maxillary premolars restored with direct EverX composite and Ribbond fibers, and to compare the results with those of natural, untreated teeth. The sample consisted of 30 freshly extracted maxillary premolars, obtained for orthodontic purposes from the Department of Orthodontics, Faculty of Dentistry, University of Aleppo. All teeth were free of cracks and caries. They were mounted in custom acrylic molds. Twenty teeth underwent endodontic treatment and MOD cavity preparation. Of these, ten teeth were restored using direct EverX composite alone, while the remaining ten received Ribbond fibers placed in the palatal canal prior to EverX restoration. The remaining ten teeth served as a control group and received no treatment. Fracture resistance was tested using a universal testing machine (Testometric M350, England). Data were analyzed using IBM SPSS Statistics 27. The results showed that endodontically treated teeth restored with EverX composite and Ribbond fibers exhibited high fracture resistance, closely approximating that of natural, intact teeth without significant differences. Teeth restored with direct EverX also demonstrated enhanced resistance, though the difference between the two restoration techniques was not statistically significant (p>0.05). Modern restorative approaches using short fiber-reinforced composites, with or without the addition of polyethylene fiber reinforcement, can significantly improve the fracture resistance of endodontically treated maxillary premolars, approaching that of natural teeth.