Abstract
OBJECTIVE: Polyethylene fiber (PF) and fiberglass (FG) posts have been recommended for intraradicular anchorage when there is a significant loss of coronal structure. However, few studies have evaluated their performance in anterior teeth combined with direct restorations as an alternative to single crowns. The objective of this study is to compare the fracture resistance and failure modes of endodontically treated anterior teeth restored with a FG post, a biomimetic technique using PF, and a direct resin composite (RC). MATERIALS AND METHODS: Forty sound upper central incisors were selected, endodontically treated, standardized for clinical crown height, and randomly distributed into four groups (n = 10): Positive control: teeth with an intact clinical crown, subjected only to access and endodontic treatment (CT), RC, PF, and FG post. Restorations were performed according to specific clinical protocols using a universal adhesive system. Fracture resistance was tested on a universal testing machine under compressive load at a 45° angle (1 mm/min). Fracture patterns were analyzed under a stereomicroscope and classified as either repairable or catastrophic. Data were analyzed using ANOVA and Fisher's exact test (α = 0.05). RESULTS: The CT group exhibited the highest mean resistance (840 N), followed by PF (740 N), FG (700 N), and RC (480 N), with a significant difference between the RC group and the others (p < 0.001). No significant difference was found among the groups regarding the failure mode (p > 0.05). CONCLUSION: FGs and PFs provided greater fracture resistance and a higher incidence of repairable fractures, with more favorable outcomes than when the procedure is performed exclusively with RC restorations.