scholarly journals Effect of Shrinking and No Shrinking Dentine and Enamel Replacing Materials in Posterior Restoration: A 3D-FEA Study

2021 ◽  
Vol 11 (5) ◽  
pp. 2215
Author(s):  
Pietro Ausiello ◽  
Amanda Maria de Oliveira Dal Piva ◽  
Alexandre Luiz Souto Borges ◽  
Antonio Lanzotti ◽  
Fausto Zamparini ◽  
...  
Keyword(s):  
Class Ii ◽  
Maximum Principal Stress ◽  
Class I ◽  
Stress Concentrations ◽  
Finite Elements Analysis ◽  
Polymerization Shrinkage ◽  
Dental Tissues ◽  
Filling Materials ◽  
3D Fea ◽  
Posterior Restorations

The aim of the present study was to investigate the effect of shrinking and no shrinking dental filling materials combination in posterior restorations under the combined effects of polymerization shrinkage and occlusal load by means of 3D Finite Elements Analysis. Six computer-generated and restored class I or class II cavities models of a lower molar were designed in the CAD software and evaluated according to the cavity and restorative procedure. Different shrinking and no shrinking adhesive materials combination with diverse Young’s modulus were considered. A food bolus was modeled on the occlusal surface replicating the chewing load using static linear analyses Polymerization shrinkage was simulated for the shrinking different restorative materials. The maximum principal stress was selected as analysis criteria. All models exhibited higher stresses along the dentine restoration interfaces with different magnitude and a similar stress trend along enamel restoration interface. Stress values up to 22 MPa and 19 MPa were recorded in the enamel and restoration, respectively. The use of elastic not shrinking material layer in combination with bulk fill composite reduced the stress magnitude in dentine and enamel to replace dental tissues. Class I and class II posterior cavities adhesively restored with shrinking filling material’s combination showed the most unfavorable stress concentrations and the multilayer technique is a promising restorative alternative in posterior adhesive restorations when deep dentin and enamel volumes are missing.

scholarly journals Bulk-Fill Composite Restorations Step-by-Step Description of Clinical Restorative Techniques Case Reports

2019 ◽  
Vol 21 (2) ◽  
pp. 23-31
Author(s):  
Renata Vasconcelos Monteiro DDS, MS, PhD Studen ◽  
Carolina Mayumi Cavalcanti Taguchi DDS, MS, PhD Student ◽  
Renata Gondo Machado DDS, MS, PhD ◽  
Silvana Batalha Silva DDS, MS, PhD ◽  
Jussara Karina Bernardon DDS, MS, PhD ◽  
...  
Keyword(s):  
Case Report ◽  
Case Reports ◽  
Class Ii ◽  
Working Time ◽  
Composite Resins ◽  
Posterior Region ◽  
Class I ◽  
Polymerization Shrinkage ◽  
New Class ◽  
And Function

Composite resins are excellent materials for direct restorations in the posterior region, satisfactorily reestablishing esthetics and function. Recently, a new class of composites has been commercialized, the so-called Bulk-fill resins. These resins may be inserted in the dental cavity in increments of 4 to 5 mm thick, and have the advantages of reducing polymerization shrinkage and clinical working time. The aim of this case report was to describe the use of bulk-fill composite resins to restore Class I and Class II cavities by means of two different restorative techniques.

Electron microscopy analysis of degenerating pancreatic ß cells in transgenic mice expressing the MHC Class I antigen Dd

1990 ◽  
Vol 48 (3) ◽  
pp. 548-549
Author(s):  
T. A. Stewart ◽  
D. Liggitt ◽  
S. Pitts ◽  
L. Martin ◽  
M. Siegel ◽  
...  
Keyword(s):  
Type I Diabetes ◽  
Disease Process ◽  
Class Ii ◽  
Class I ◽  
Type I ◽  
Aberrant Expression ◽  
Mhc Molecules ◽  
Endogenous Insulin ◽  
Class Ii Mhc ◽  
Ifn Γ

Insulin-dependant (Type I) diabetes mellitus (IDDM) is a metabolic disorder resulting from the lack of endogenous insulin secretion. The disease is thought to result from the autoimmune mediated destruction of the insulin producing ß cells within the islets of Langerhans. The disease process is probably triggered by environmental agents, e.g. virus or chemical toxins on a background of genetic susceptibility associated with particular alleles within the major histocompatiblity complex (MHC). The relation between IDDM and the MHC locus has been reinforced by the demonstration of both class I and class II MHC proteins on the surface of ß cells from newly diagnosed patients as well as mounting evidence that IDDM has an autoimmune pathogenesis. In 1984, a series of observations were used to advance a hypothesis, in which it was suggested that aberrant expression of class II MHC molecules, perhaps induced by gamma-interferon (IFN γ) could present self antigens and initiate an autoimmune disease. We have tested some aspects of this model and demonstrated that expression of IFN γ by pancreatic ß cells can initiate an inflammatory destruction of both the islets and pancreas and does lead to IDDM.

Tetracycline inducible MHC class II and class I expression

1997 ◽  
Vol 56 (1-3) ◽  
pp. 84
Author(s):  
D Witherden
Keyword(s):  
Mhc Class Ii ◽  
Class Ii ◽  
Class I

Pictish Horse Carvings

1991 ◽  
Vol 17 (1) ◽  
pp. 53-62
Author(s):  
Irene Hughson
Keyword(s):  
Class Ii ◽  
Class I ◽  
Early Historic Period ◽  
High Quality ◽  
Historic Period ◽  
Agricultural Economy ◽  
Different Types ◽  
Early Historic

Summary This paper examines the horse carvings to be found on Class I and Class II Pictish sculptured stones and considers their reliability as evidence of the sort of horses and ponies that would have existed in the Early Historic Period. An attempt is made to show that the availability in Britain of good sized, high quality riding horses during that period is not inconsistent with what is known of the development and distribution of different types of horses in pre-hislory. The importance of horses and ponies in Early Historic societies is stressed and inferences drawn about the agricultural economy that could support horses and the skilled specialists required to look after them.

Inhibition of cytokine-induced MHC class II but not class I molecule expression on mouse islet cells by niacinamide and 3-aminobenzamide

Diabetes ◽  
1990 ◽  
Vol 39 (9) ◽  
pp. 1125-1130 ◽  
Author(s):  
K. Yamada ◽  
E. Miyajima ◽  
K. Nonaka
Keyword(s):  
Mhc Class Ii ◽  
Islet Cells ◽  
Class Ii ◽  
Class I ◽  
Mouse Islet

Different roles of class I and class II Clostridium histolyticum collagenase in rat pancreatic islet isolation

Diabetes ◽  
1995 ◽  
Vol 44 (2) ◽  
pp. 227-233 ◽  
Author(s):  
G. H. Wolters ◽  
G. H. Vos-Scheperkeuter ◽  
H. C. Lin ◽  
R. van Schilfgaarde
Keyword(s):  
Pancreatic Islet ◽  
Class Ii ◽  
Class I ◽  
Islet Isolation ◽  
Clostridium Histolyticum ◽  
Pancreatic Islet Isolation ◽  
Clostridium Histolyticum Collagenase ◽  
Rat Pancreatic Islet

MHC Sınıf I ve MHC Sınıf II Gen Düzenlenmesi

2020 ◽  
Vol 8 (3) ◽  
pp. 144-156
Author(s):  
Şule KARATAŞ ◽  
Fatma SAVRAN OĞUZ
Keyword(s):  
Immune Response ◽  
T Cells ◽  
Gene Regulation ◽  
Mhc Class I ◽  
Mhc Class Ii ◽  
Class Ii ◽  
Class I ◽  
Mhc Molecules ◽  
Class Ii Mhc ◽  
Regulation Mechanisms

Introduction: Peptides obtained by processing intracellular and extracellular antigens are presented to T cells to stimulate the immune response. This presentation is made by peptide receptors called major histocompatibility complex (MHC) molecules. The regulation mechanisms of MHC molecules, which have similar roles in the immune response, especially at the gene level, have significant differences according to their class. Objective: Class I and class II MHC molecules encoded by MHC genes on the short arm of the sixth chromosome are peptide receptors that stimulate T cell response. These peptides, which will enable the recognition of the antigen from which they originate, are loaded into MHC molecules and presented to T cells. Although the principles of loading and delivering peptides are similar for both molecules, the peptide sources and peptide loading mechanisms are different. In addition, class I molecules are expressed in all nucleated cells while class II molecules are expressed only in Antigen Presentation Cells (APC). These differences; It shows that MHC class I is not expressed by exactly the same transcriptional mechanisms as MHC class II. In our article, we aimed to compare the gene expressions of both classes and reveal their similarities and differences. Discussion and Conclusion: A better understanding of the transcriptional mechanisms of MHC molecules will reveal the role of these molecules in diseases more clearly. In our review, we discussed MHC gene regulation mechanisms with presence of existing informations, which is specific to the MHC class, for contribute to future research. Keywords: MHC class I, MHC class II, MHC gene regulation, promoter, SXY module, transcription

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