Purpose: To investigate and compare the effect of different heat treatment on the metal- ceramic bonding strength and the interfacial microstructure of the Co-Cr alloy.
Methods: Thirty specimens were made according to ISO 9693,and then divided into 3 groups (n=10) through the measurements .Group A(degassed 60s):degassed and then maintained 60s in 980 degrees centigrade Group B(degassed 60s and preoxidation 60s): degassed and maintained 60s in 980 degrees centigrade, then were maintained continuously for 60s in 980 degrees centigrade after re-gassed,Group C(degassed 120s): degassed and maintained 120s in 980 degrees centigrade. The bonding strengths of the three groups were evaluated through three point bending test. Six specimens divided into 3 group were made in the same method to observe the metal-ceramic interface through scanning electronic microscope(SEM) and energy dispersive spectrum(EDS).The bonding strength data were analyzed using ANOVA and Bonferroni's test by SPSS13.0 software package.
Results: The mean value of bonding strength was (39.03±2.70)MPa for group A, (34.43±2.36)MPa for group B, (31.65±1.49)MPa for group C, respectively. There were significant difference between every two groups (P<0.05). SEM demonstrated that the width of interfacial transition layer was 12.3-16.4μm in group A, 15.2-21.8μm in group B and 26.3-32.2μm in group C.
Conclusions: Higher metal-ceramic bonding strength for Co-Cr alloy will be formed under the situation of degassed,and maintained 60s in 980 degrees centigrade ; while extending degassed time, prolonging the heat maintained time and preoxidation after degassing will reduce metal-ceramic bonding strength.
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J Mol Model
January 2025
Escuela Superior de Física y Matemáticas, IPN S/N, Edificio 9 de la Unidad Profesional "Adolfo López Mateos", Col. Lindavista, Alc. Gustavo A. Madero, 07738, Mexico City, Mexico.
Context: "Nanostructure of graphene-reinforced with polymethyl methacrylate" (PMMA-G), and vice versa, is investigated using its molecular structure, in the present work. The PMMA-G nanostructure was constructed by bonding PMMA with graphene nanosheet in a sense to get three different configurations. Each configuration consisted of polymeric structures with three degrees of polymerization (such as monomers, dimers, and trimers polymers, respectively).
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January 2025
Department of Endodontics, Faculty of Dentistry, Dicle University, Diyarbakir, Turkey.
BACKGROUND Different temperature conditions can affect the efficiency of irrigation solutions and consequently the ability of canal sealers to bond to root canal walls. The aim of this endodontic study was to evaluate the effect of irrigation solutions at different temperatures on the bond strength of a bioceramic-based root canal sealer. MATERIAL AND METHODS Root canal preparations were completed through irrigation with the following solutions: Group 1 was irrigated with 5 ml NaOCl (sodium hypochlorite) +5 ml EDTA (Ethylenediamine tetra-acetic acid) (22°C); Group 2 was irrigated with 5 ml NaOCl +5 ml EDTA (37°C); Group 3 was irrigated with 5 ml NaOCl +5 ml GA (Glycolic acid) (22°C); Group 4 was irrigated with 5 ml NaOCl +5 ml GA (37°C), Group 5 was irrigated with 20 ml Dual Rinse® HEDP (Etidronate) - NaOCl mixture (22°C); and Group 6 was irrigated with 20 ml of Dual Rinse® HEDP mixture (37°C).
View Article and Find Full Text PDFSci Rep
January 2025
Department of Civil Engineering, University of Guilan, Rasht, Iran.
Glassphalt suffers from performance defects, especially against moisture damage and fatigue cracking. In this research, the performance of glassphalt modified with CF has been evaluated against moisture damage, fatigue cracking and rutting. Based on this, Modified Lottman, Wilhelmy Plate (WP), Indirect Tensile Stiffness Modulus (ITSM), Indirect Tensile Fatigue (ITF), and Repeated Load Axial (RLA) tests have been performed on glassphalt modified with CF.
View Article and Find Full Text PDFSci Rep
January 2025
Department of Conservative Dentistry and Endodontics, Saveetha Dental College and Hospitals, Saveetha Institute of Medical and Technical Sciences, Saveetha University, Chennai, Tamil Nadu, 600077, India.
Polydopamine (PD), inspired by the wet adhesion mechanism of mussel foot proteins, has emerged as a promising adhesive material with wide-ranging applications. This study aimed to compare the adhesive properties of PD and Glass Ionomer Cement (GIC) on enamel and dentin substrates, evaluating PD's potential as an alternative adhesive in dental practice. A total of 120 human premolars were prepared, with 80 teeth allocated for Scanning Electron Microscopy (SEM) analysis and 40 teeth reserved for shear bond strength testing.
View Article and Find Full Text PDFInt J Paediatr Dent
January 2025
Department of Paediatric Dentistry, Medical Centre for Dentistry, University Medical Centre Giessen and Marburg GmbH (Campus Giessen), Justus-Liebig-University, Giessen, Germany.
Background: Limited reports are available regarding bonding of universal adhesives to primary teeth' enamel.
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