Clinical evaluation of composite restorations with polyethylene fiber placement in endodontically treated premolar and molar teeth

The aim of this study was to compare the clinical performance of direct composite restorations with polyethylene fiber (Ribbond) placed in different orientations (O shape; buccolingual I shape; mesiodistal I shape) in endodontically treated premolar and molar teeth at 6- and 12-month follow-ups. The study included 85 patients (59 females, 26 males) aged between 18 and 50 years, and a total of 90 endodontically treated posterior teeth. The Clearfil SE Bond adhesive system, G-aenial Universal Injectable, G-aenial A'chord universal composites, and Ribbond (polyethylene fiber) were used in the restorations. According to the remaining tooth structure, Ribbond was placed in different orientations and the restorations were divided into three groups: Group 1: Ribbond was placed in a circular orientation covering the pulpal floor, Group 2: Ribbond was placed on the pulpal wall in a mesiodistal I shape, Group 3: Ribbond was placed on the pulpal wall in a buccolingual I shape. All restorations were evaluated at the 1st week, 6th month, and 12th month follow-ups according to modified USPHS criteria. For statistical analysis, the time-dependent changes in clinical scores of the restorations grouped by fiber orientation (O, MD, and BL) were assessed using the Cochran Q test with Bonferroni correction. The Alpha score rates of restorations with different fiber orientations at the same time point were compared using the Fisher-Freeman-Halton test (p < 0.05). Within the limitations of our study, composite restorations applied with Ribbond in three different orientations in endodontically treated premolar and molar teeth demonstrated successful and similar clinical results at both 6- and 12-month follow-ups. Key words: Ribbond-reinforced composite, endodontically treated posterior teeth, modified USPHS, different fiber placement.