Compressive Strength and Porosity Evaluation of Innovative Bidirectional Spiral Winding Fiber Reinforced Composites

Abstract

The aim of this in vitro study was to investigate the compressive strength and the bulk porosity of a bidirectional (bFRC) and an experimental bidirectional spiral winding reinforced fiber composite (bswFRC). Cylindrical-shape specimens were prepared for each material group and processed for the evaluation of compressive strength after different storage conditions (dry, 1 and 3 months) in distilled water at 37 °C. The specimens were also assessed for the degree of bulk porosity through X-ray tomography. A scanning electron microscope (SEM) was used to determine the fracture mode after a compressive strength test. Data were statistically analyzed using Two-Way Analysis of Variance (ANOVA). A significantly lower compressive strength was obtained in dry conditions, and after 1 month of water immersion, with the specimens created with bFRC compared to those made with bswFRC (p < 0.05). No significant difference (p > 0.05) was found between the two groups after 3 months of water immersion. However, the presence of water jeopardized significantly the compressive strength of bswFRC after water storage. The type of fracture was clearly different between the two groups; bswFRC showed a brutal fracture, whilst bFRC demonstrated a shear fracture. The bswFRC demonstrated higher pore volume density than bFRC. In conclusion, bswFRC is characterized by greater compressive strength compared to bFRC in dry conditions, but water-aging can significantly decrease the mechanical properties of such an innovative FRC. Therefore, both the novel bidirectional spiral winding reinforced fiber composites (bswFRC) and the bidirectional fiber reinforced composites (bFRC) might represent suitable materials for the production of post-and-core systems via CAD/CAM technology. These findings suggest that both FRC materials have the potential to strengthen the endodontically treated teeth.

Physicochemical and Mechanical Properties of Premixed Calcium Silicate and Resin Sealers

“…Volume reconstruction was performed with the software Xact64 (RX Solutions) after applying geometrical corrections and ring artefact attenuation. Such an image process was performed using the Avizo software (ThermoFisher, Waltham, MA, USA) that allowed us to (i) de-noise the images with a median filter; (ii) segmentate the image intensity to reveal the objects of interest (here, the pores); (iii) remove insignificant small objects (below a size of 10 pixels from the segmented 3D data); and (iv) determine the 3D geometrical aspects of the objects of interest (volume and equivalent diameter) [ 28 ].…”

Special Issue “Recent Advances in Biomaterials and Dental Disease” Part I

“…Until now, there is no specific restoration for endodontically treated teeth which could avoid the restorative complications that lead to failure and tooth extraction [29][30][31]. Recently, Kharouf et al [32] studied a new material-a bidirectional, spiral-winding, fiber-reinforced composite-which demonstrated a high compressive strength resistance; this material could be a promising solution for restoring endodontically treated teeth. In addition, different techniques could be used to fabricate the final restoration, such as the digital light-processing 3D-printing technique [7].…”

Do the Mechanical Properties of Calcium-Silicate-Based Cements Influence the Stress Distribution of Different Retrograde Cavity Preparations?

“…The software Xact64 (Version: 22.01.1 2022-03-14, RX Solutions, Chavanod, France) was used to perform the volume reconstruction after the application of ring artifact attenuation and the geometrical corrections. The Avizo software (Version: 3D 2022-2) was used in the image process to remove insignificant small objects, de-noise the images with a median filter, determine the 3D geometrical aspects of the objects of interest, and segment the image intensity in order to reveal the objects of interest [19].…”