Objectives: The aim of this study was to determine the Weibull and slow crack growth (SCG) parameters of bulk-fill resin based composites. The strength degradation over time of the materials was also assessed by strength-probability-time (SPT) analysis.
Methods: Three bulk-fill [Tetric EvoCeram Bulk Fill (TBF); X-tra fil (XTR); Filtek Bulk-fill flowable (BFL)] and a conventional one [Filtek Z250 (Z250)] were studied. Seventy five disk-shaped specimens (12mm in diameter and 1mm thick) were prepared by inserting the uncured composites in a stainless steel split mold followed by photoactivation (1200mW/cm(2)/20s) and storage in distilled water (37°C/24h). Degree of conversion was evaluated in five specimens by analysis of FT-IR spectra obtained in the mid-IR region. The SCG parameters n (stress corrosion susceptibility coefficient) and σf0 (scaling parameter) were obtained by testing ten specimens in each of the five stress rates: 10(-2), 10(-1), 10(0), 10(1) and 10(2)MPa/s using a piston-on-three-balls device. Weibull parameter m (Weibull modulus) and σf0 (characteristic strength) were obtained by testing additional 20 specimens at 1MPa/s. Strength-probability-time (SPT) diagrams were constructed by merging SCG and Weibull parameters.
Results: BFL and TBF presented higher n values, respectively (40.1 and 25.5). Z250 showed the highest (157.02MPa) and TBF the lowest (110.90MPa) σf0 value. Weibull analysis showed m (Weibull modulus) of 9.7, 8.6, 9.7 and 8.9 for TBF, BFL, XTR and Z250, respectively. SPT diagram for 5% probability of failure showed strength decrease of 18% for BFL, 25% for TBF, 32% for XTR and 36% for Z250, respectively, after 5 years as compared to 1 year.
Significance: The reliability and decadence of strength over time for bulk-fill resin composites studied are, at least, comparable to conventional composites. BFL shows the highest fatigue resistance under all simulations followed by TBF, while XTR was at par with Z250.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/j.dental.2015.06.006 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Predicting airway immune responses and protection from immune parameters in blood following immunization in a pig influenza model.
Front Immunol
January 2025
Nuffield Department of Medicine, Pandemic Sciences Institute, University of Oxford, Oxford, United Kingdom.
Whereas the intranasally delivered influenza vaccines used in children affect transmission of influenza virus in the community as well as reducing illness, inactivated influenza vaccines administered by intramuscular injection do not prevent transmission and have a variable, sometimes low rate of vaccine effectiveness. Although mucosally administered vaccines have the potential to induce more protective immune response at the site of viral infection, quantitating such immune responses in large scale clinical trials and developing correlates of protection is challenging. Here we show that by using mathematical models immune responses measured in the blood after delivery of vaccine to the lungs by aerosol can predict immune responses in the respiratory tract in pigs.
View Article and Find Full Text PDFA comparison of the physiochemical features of three tertiary hybrid pigs with and without spent coffee ground supplementation.
J Anim Sci Technol
November 2024
Department of Animal Industry Convergence, Kangwon National University, Chuncheon 24341, Korea.
The objective of this experiment was to evaluate the physiochemical characteristics of three tertiary hybrids (crossbreeds) of pigs, with and without coffee supplementation. A total of fifty pigs of different mixed breeds Landrace × Yorkshire × Duroc (LYD), Yorkshire × Berkshire (YB), and Yorkshire × Woori (YW); 113.45 kg ± 3.
View Article and Find Full Text PDFBound states in the continuum (BIC) refers to waves that are entirely confined within the continuous spectrum of radiation waves without interacting with them. In our study, we attempted to construct a waveguide satisfying BIC conditions by forming a polymer layer on a 4H-SiC substrate, positioned on an insulator. By fine-tuning the waveguide parameters, we minimized losses to the substrate continuum and determined that the lowest loss meeting BIC conditions occurs when the HSQ width is 1.
View Article and Find Full Text PDFAnatomical Targeting of the Superior Cervical Ganglion on Computed Tomography Imaging for Guidance of Endovascular Transmural Intervention.
World Neurosurg
December 2024
Department of Neurosurgery, University of California Los Angeles, Los Angeles, California, USA. Electronic address:
Article Synopsis
- Endovascular transmural targeting of the superior cervical ganglion (SCG) is being explored as a minimally invasive method for delivering therapeutics, potentially beneficial for certain medical conditions due to its proximity to major cervical blood vessels.
- A retrospective study analyzed CT angiography from patients with head trauma or brain aneurysms to assess the dimensions of the SCG and its relationship to cervical vessels.
- Results indicated that 95% of SCGs are accessible via an endovascular approach from the internal carotid artery, which has the longest connection with the SCG, demonstrating the anatomical feasibility of this targeting method.
DR.BEAT: Rule-Based Algorithm for SCG Analysis Without ECG Reference.
Stud Health Technol Inform
August 2024
Peter L. Reichertz Institute for Medical Informatics, Germany.
The DR.BEAT project aims to develop an accelerometer-based, wearable sensor system for measuring ballistocardiographic (BCG) signals, coupled with signal processing and visualization, to support cardiac health monitoring. A rule-based heartbeat detection was developed to enable the derivation of health parameters independent of an existing reference.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!