FRC (Fiber-reinforced composite) posts have been used since the beginning of the 90s with the introduction of carbon fiber posts. Fiber posts are widely used to restore endodontically treated teeth that have insufficient coronal tooth structure. Many in vitro and in vivo studies have shown the advantage of using FRC over prefabricated and cast metal post especially indicated in narrow root canals which are prone to vertically root fracture. The most frequent failure of FRC is debonding of a post at the resin cement/dentin interface. Bonding to dentin may be achieved by using etch-and-rinse and self-etch adhesives. The bond strength formed by self-adhesive cements is noticeably lower in comparison to the bond strength formed with resin cements applied in combination with etch-and-rinse adhesives. In an attempt to maximize resin bonding to fiber posts, several surface treatments have been suggested. Sandblasting with alumina particles results in an increased surface roughness and surface area without affecting the integrity of the post as long as it is applied by 50 microm alumina particles at 2.5 bars for maximally 5 seconds at a distance of 30 mm. The efficiency of post salinization is controversial and its contribution to the retention is of minor importance. Hydrofluoric acid has recently been proposed for etching glass fiber posts but this technique produced substantial damage to the glass fibers and affected the integrity of the post. Delayed cementation of fiber post (at least 24h post endodontic treatment) resulted in higher retentive strengths in comparison to immediate cementation and the best results were obtained when the luting agent was brought into the post space with lentulo spirals or specific syringes. The resin cement film thickness also influences the pullout strengths of fiber-reinforced posts .The highest bond strength values were obtained when the cement layer oversized the post spaces but not larger than 0.3 mm. The use of core build-up materials as post luting cements is not recommended. The use of FRC post, combined with proper adhesive cementation technique can give an excellent solution when restoring endodontically treated teeth that are prone to fracture.
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Sci Adv
January 2025
Guangdong Provincial Key Laboratory of Optical Fiber Sensing and Communications, Institute of Photonics Technology, Jinan University, Guangzhou 510632, China.
Artificial nanostructures with ultrafine and deep-subwavelength features have emerged as a paradigm-shifting platform to advanced light-field management, becoming key building blocks for high-performance integrated optoelectronics and flat optics. However, direct optical inspection of integrated chips remains a missing metrology gap that hinders quick feedback between design and fabrications. Here, we demonstrate that photothermal nonlinear scattering microscopy can be used for direct imaging and resolving of integrated optoelectronic chips beyond the diffraction limit.
View Article and Find Full Text PDFJ Funct Biomater
December 2024
Department of Endodontics, Faculty of Dentistry, Kütahya Health Sciences University, 43020 Kütahya, Türkiye.
This study evaluated the effect of resin cements and post-space irrigation solutions on the push-out bond strength of diabetic and non-diabetic dentin. A total of 160 human central teeth (80 diabetic, 80 non-diabetic) were prepared using X5 files and obturated with AH Plus sealer and X5 gutta-percha. Post spaces were prepared, and teeth were divided into eight groups based on resin cements (Variolink N, Panavia SA Universal) and irrigation protocols (saline, saline + 2% CHX).
View Article and Find Full Text PDFJ Prosthodont
January 2025
Department of Prosthodontics, Yeditepe University Faculty of Dentistry, Istanbul, Turkey.
Purpose: To compare the effect of post-and-core material type and production technique on the fracture resistance of teeth.
Materials And Methods: Sixty human maxillary central incisors were used for the study. Root canal treatments were performed, and the post cavities were created.
Photodiagnosis Photodyn Ther
January 2025
Department of Prosthetic Dental Sciences, College of Dentistry. King Saud University. Riyadh, Saudi Arabia PO Box-60169. Electronic address:
Aim: To investigate the effectiveness of unconventional post space disinfection techniques, specifically Er:YAG laser, Temoporfin, and Carbon Nanoparticles (CNPs), in improving Martens hardness (MH), eliminating the smear layer (SL), and enhancing the push-out bond strength (PBS) of glass fiber posts in canal dentin.
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Heliyon
July 2024
Department of Cardiovascular Surgery, First Affiliated Hospital of Nanjing Medical University, Nanjing, 210029, China.
Recent studies have attempted to characterize the layer-specific mechanical and microstructural properties of the aortic tissues in either normal or pathological state to understand its structural-mechanical property relationships. However, layer-specific tissue mechanics and compositions of normal and dissected ascending aortas have not been thoroughly compared with a statistical conclusion obtained. Eighteen ascending aortic specimens were harvested from 13 patients with type A aortic dissection and 5 donors without aortic diseases, with each specimen further excised to obtain three tissue samples including an intact wall, an intima-media layer and an adventitia layer.
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