Objectives: Dentin microstructure undergoes changes with age and its materials properties degrade over time. In the present study, we investigate the coupled influence of increased filled tubules and decreased materials properties on the fracture behavior of human dentin.
Methods: We assume degraded materials properties are linked with increased advanced glycation end-products (AGEs) crosslinks in dentin tissue. We use morphological data of human molars to create 2D and 3D models of dentin microstructure, and utilize a phase field fracture framework to study crack growth trajectories. We construct aged dentin samples (i.e., filled tubules and degraded properties) and compare the fracture results with the samples without age-related changes.
Results: The simulations show an increase in the number of filled tubules can deactivate the toughening mechanisms such as crack deflection and microcracking. In addition, filled tubules have adverse impacts on the ability of peritubular dentin to shield microcracking. We further show how the dentinal tubules' orientations affect the crack surface growth. We also investigate that an increase in the AGEs level can result in increased brittleness.
Significance: The developed model and findings of the present study provide region-dependent information on crack growth trajectories as well as more understanding of crack surface growth at the presence of filled tubules.
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http://dx.doi.org/10.1016/j.dental.2022.09.009 | DOI Listing |
Acta Parasitol
January 2025
Department of Molecular Biology and Genetics, Faculty of Arts and Science, Ordu University, Ordu, Türkiye.
Purpose: The brown marmorated stink bug, Halyomorpha halys (Hemiptera: Pentatomidae), is an invasive and a highly polyphagous species with a strong dispersal capacity. Unfortunately, there is currently no effective control method that can prevent or reduce the economic loss caused by this pest. Among natural enemies, microsporidia cause infections in insects so that they can generally shorten life span, reduce fertility and inhibit growth.
View Article and Find Full Text PDFBiol Reprod
January 2025
Department of Anatomy and Cell Biology, Brody School of Medicine, East Carolina University, Greenville, NC USA.
The adult mammalian testis is filled with seminiferous tubules, which contain somatic Sertoli cells along with germ cells undergoing all phases of spermatogenesis. During spermatogenesis in postnatal mice, male germ cells undergo at least 17 different nomenclature changes as they proceed through mitosis as spermatogonia (=8), meiosis as spermatocytes (=6), and spermiogenesis as spermatids (=3) [1-6]. Adding to this complexity, combinations of germ cells at each of these stages of development are clumped together along the length of the seminiferous tubules.
View Article and Find Full Text PDFCalcif Tissue Int
January 2025
Department of Periodontology, Division of Oral Biology and Disease Control, Osaka University Graduate School of Dentistry, Osaka, Japan.
Human dentin performs its function throughout life, even though it is not remodeled like bone. Therefore, dentin must have extreme durability against daily repetitive loading. Elucidating its durability requires a comprehensive understanding of its shape, structure, and anisotropy at various levels of its structure.
View Article and Find Full Text PDFDent J (Basel)
December 2024
Faculty of Dentistry, Iuliu Hatieganu University of Medicine and Pharmacy, 400012 Cluj-Napoca, Romania.
Adhesion within endodontic obturation material and root canal walls improves the efficacy of the endodontic treatment by establishing a barrier that inhibits reinfection and entombs residual bacteria. This study evaluates the push-out bond strength (POBS) of calcium silicate sealers compared to an epoxy-resin-based sealer. A total of 36 extracted mono-radicular teeth were prepared with Pro Taper Ultimate and irrigated with 5.
View Article and Find Full Text PDFShanghai Kou Qiang Yi Xue
October 2024
Department of Periodontology, School and Hospital of Stomatology, Cheeloo College of Medicine, Shandong University; Shandong Key Laboratory of Oral Tissue Regeneration; Shandong Engineering Research Center of Dental Materials and Oral Tissue Regeneration; Shandong Provincial Clinical Research Center for Oral Diseases. Jinan 250012, Shandong Province, China. E-mail:
Purpose: This study was aimed to compare the difference between iRoot SP and AH Plus on root canal sealing ability for teeth extracted due to severe periodontitis and explore whether the dentin tubule pathway plays an important role in the development of endodontic-periodontic lesions(EPL), in order to provide a theoretical basis for selection of proper time for root canal therapy and suitable root canal sealants in patients with EPL.
Methods: Fifty single-root anterior teeth extracted due to severe periodontitis were selected. The roots were completely debrided to remove the calculus, dental plaque and cementum.
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