The Influence on Fracture Resistance of Different Composite Resins and Prefabricated Posts to Restore Endodontically Treated Teeth

Abstract

Recent formulations of resin-based composites have incorporated different combinations of materials. However, the mechanical and bonding behavior of these materials with intraradicular posts are unclear. This study aimed to evaluate the effect of light-cure and dual-cure resin composite posts on the fracture resistance of endodontically-treated teeth. Materials and Methods: Ninety extracted human upper canines were selected and randomly divided into nine groups (n=10): (G1) endodontically treated teeth without endodontic posts; (G2) glass-fiber post cemented with glass-ionomer cement; (G3) endodontic post by dual-cure composite resin (Rebilda DC); (G4) endodontic post by dual-cure composite resin (Cosmecore); (G5) endodontic post by dual-cure composite resin (Bis-Core); (G6) endodontic post by light-cure composite resin; (G7) glass-fiber post customized with flowable composite resin; (G8) glass-fiber post cemented with light-cure composite resin; (G9) glass-fiber post cemented with self-adhesive resin cement. After the post insertion, all specimens were subjected to mechanical (250,000 cycles) and thermocycling (6000 cycles, 5 °C/55 °C) and immediate loading at 45 degrees in a universal testing machine until fracture. The data were analyzed by one-way ANOVA and multiple comparisons using the Fisher LSD Method (p < 0 05). Results: The mean failure loads (±SD) for the groups ranged from 100.7 ± 22.6 N to 221.9 ± 48.9 N. The G1 group (without endodontic posts) had a higher fracture strength than all experimental groups (p < 0.001). Conclusions: Within the limitations, the light- and dual-cure post technique did not present lower fracture resistance values as compared to the conventional glass-fiber post.

The effect of touch-cure polymerization on the push-out bond strength of fiber posts

“…This complex improves fracture resistance through the good distribution of stresses along the root canal. These outcomes are consistent with previous articles ( Gutiérrez et al, 2022 , Pamato et al, 2023 ).…”

“…These findings may be related to the use of a new trend of customized (GF) posts that adapt to the root walls more effectively than the prefabricated single fiber posts and reduce the volume of the luting agent around the posts increasing the fit of the posts and reducing the possibility of post-debonding. Thick cement film is prone to voids, pores, and cracks increasing the risk of catastrophic fractures or post-debonding ( Jamel et al, 2019 , Pamato et al, 2023 ). In addition, the braided structure of the (GFs) modulates the applied forces before they are transferred to the tooth structure and enhances the plastic deformation of the dentin walls forming a post-dentin-cement mono-block structure in the root to resist loads as a single unit.…”

“…However, clinical limitations have been associated with the mismatch in modulus of elasticity and over-instrumentation. In the past few years, prefabricated fiber posts have become another technique to reduce the possibility of tooth fracture ( Alamdari et al, 2023 , Pamato et al, 2023 ). Prefabricated glass fiber-reinforced composite (GFRC) posts have received more attention owing to their better clinical performance, aesthetics, and high flexural strength (Duarte Lopes et al, 2021 , Al Najajrah et al, 2023 ).…”

Effects of glass fibers reinforced and non-reinforced composite resin on fracture behavior of severely destructed primary incisors and restored with post and core system

“…The rod tip was applied to mid -palatal surface of restoration and force-inducing fracture was recorded in Newton. All specimens were examined visually for failure type that was categorized into: type 1; partial fracture of coronal restoration but intact post, type 2; coronal fracture of post and restoration, type 3: post-debonding with restoration, and type 4; root fracture ( Pamato et al, 2023 ).…”