Objectives: The aim of this study was to investigate whether the diameter and direction of the plunger and simulation of the periodontal ligament (PDL) affected the stress distribution in endodontically treated premolars.
Methods: A fracture strength test was simulated via finite element analysis. A base model was set up, and the following parameters were modified: plunger diameter (3 mm vs. 6 mm), plunger direction (vertical vs. 135° angular to the central fossa), and PDL simulation. The analysis was conducted using the CosmosWorks structural analysis program, and the results are presented in terms of von Mises stresses.
Results: The smaller plunger increased the stresses at the contact area of the crown, but the plunger diameter had no effect on the stress distribution within the root. An angular plunger direction increased stresses within the root, as well as at the buccal cusp of the crown, compared with the vertical direction. Simulation of the PDL caused higher stress accumulation, especially in the cervical region of the root.
Conclusions: The plunger diameter had no effect on the stress distribution in the roots, whereas the plunger direction and PDL simulation did affect the stress distribution. More stringent standards can be established by taking such parameters into account when performing fracture testing in future studies.
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http://dx.doi.org/10.5395/rde.2019.44.e15 | DOI Listing |
Foot Ankle Surg
January 2025
Biomechanics Research Laboratory, School of Mechanical & Materials Engineering, Indian Institute of Technology Mandi, Mandi, Himachal Pradesh 175075, India. Electronic address:
Background: Tibial bone fractures in the malleolar regions are a major concern during the early postoperative period of total ankle replacement (TAR), affecting patient outcomes such as stability and recovery. Design, placement, and anatomic misalignment of implant components can contribute to malleolar fractures. The aim of this study is to understand the influence of implant design features, including keel, peg, stem, and bar type design, and bone-implant interfacial conditions on malleolar fracture following TAR.
View Article and Find Full Text PDFEcotoxicol Environ Saf
January 2025
Center for Clinical and Epidemiologic Research, Beijing An Zhen Hospital, Capital Medical University, Beijing, China; Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China; National Clinical Research Center of Cardiovascular Diseases, Beijing, China; The Key Laboratory of Remodeling-Related Cardiovascular Diseases, Ministry of Education, Beijing, China; The Beijing Municipal Key Laboratory of Clinical Epidemiology, Beijing, China. Electronic address:
Background: Ambient temperatures and PM can trigger myocardial infarction (MI), while little is known about the complex interplay between these two factors on MI, especially morbidity.
Objectives: To investigate bidirectional effect modifications of temperature and PM on MI morbidity and mortality.
Methods: A time-stratified case-crossover study was conducted utilizing high-resolution data of temperature and PM, along with 498,077 MI cases from the citywide registry in Beijing, China from 2007 to 2021.
Plant Physiol Biochem
January 2025
State Key Laboratory of Herbage Improvement and Grassland Agro-ecosystems, College of Pastoral Agriculture Science and Technology, Lanzhou University, Lanzhou, Gansu 730020, China. Electronic address:
Alfalfa (Medicago sativa L.) is a prominent and distinct species within the pasture germplasm innovation industry. However, drought poses a substantial constraint on the yield and distribution of alfalfa by adversely affecting its growth.
View Article and Find Full Text PDFNat Commun
January 2025
Department of Physics and Competence Centre for Catalysis, Chalmers University of Technology, SE-412 96, Göteborg, Sweden.
The performance of Cu-exchanged chabazite (Cu-CHA) for the ammonia-assisted selective catalytic reduction of NO (NH-SCR) depends critically on the presence of paired complexes. Here, a machine-learning force field augmented with long-range Coulomb interactions is developed to investigate the effect of Al-distribution and Cu-loading on the mobility and pairing of complexes. Performing unbiased and constrained molecular dynamics simulations, we obtain unique information inaccessible to first-principle calculations and experiments.
View Article and Find Full Text PDFChemosphere
January 2025
Nanoqam, Department of Chemistry, University of Quebec at Montreal, H3C 3P8, Canada; École de technologie supérieure, Montréal (Québec), Canada, H3C 1K3. Electronic address:
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