Effect of Resin Cement Porosity on Retention of Glass-Fiber Posts to Root Dentin: An Experimental and Finite Element Analysis

Abstract

The aim of this study was to evaluate the effect of porosity of self-adhesive resin on the stress distribution, post retention and failure mode of fiber post cemented to human root dentin. Ten human central upper incisors with circular root canal were selected. They were sectioned with 15 mm and were endodontically filled. The roots were scanned using micro-CT after post space preparation for root filling remaining evaluation. Fiber posts were cemented using self-adhesive resin cement (Rely X U200, 3M-ESPE). Two 1-mm-thick slices from the cervical, medium and apical thirds were scanned for resin cement bubbles volume measurements and submitted to a push-out test (PBS). Three operators using stereomicroscopy and confocal laser microscopy classified the failure mode. Stress distributions during the push-out test were analyzed using 3D finite element analysis. PBS values (MPa) were submitted to one-way ANOVA and Tukey's post hoc tests and the failure modes using the Kappa coefficient to assess inter-operator agreement. Chi-square test was used to determine significant differences between the methods ( = 0.05). Push-out bond strength was significantly affected by the bubbles presence in all root depth (p<0.05). The stress concentration was higher when the bubbles were present. Adhesive dentin/resin cement interface failure was the most frequent type of failure. Confocal microscopy was better than stereomicroscopy for failure analysis. Bubbles generated during resin cement insertion into the root canal negatively affect the stress distribution and the bond strength. The use of confocal microscopy is recommended for failure analysis.

Effect of Anatomical Customization of the Fiber Post on the Bond Strength of a Self-Adhesive Resin Cement

“…The most prevalent failure mode in this study is in agreement with earlier studies and reinforces the assertion that the most sensitive interface is between the dentin and resin cement, as it has the greatest concentration of stress [25]. …”

Effect of Fabrication Technique and Thermal Cycling on the Bond Strength of CAD/CAM Milled Custom Fit Anatomical Post and Cores: An In Vitro Study

“…A thick layer of cement is prone to volumetric shrinkage and polymerization stress. As a result, voids and gaps are generated between the cement and root dentin, which will reduce the bonding area inside the canal and concentrate the stress on the remaining intact interface (Fig ). Custom‐fit posts and cores ensure a better fit in the canal (Fig ) and an increase in the pressure during cementation, which may result in better contact between the cement/post assembly and the dentin .…”

Fratura Dental Com Tratamento Multidisciplinar

“…Contudo, a resistência de união de cimento resinoso e pino de fibra é um fator crítico para o sucesso de procedimentos endodônticos (SILVA et al, 2015). A utilização do pino foi associada à colagem …”