The Experts below are selected from a list of 10665 Experts worldwide ranked by ideXlab platform
Lippo V J Lassila - One of the best experts on this subject based on the ideXlab platform.
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mechanical properties fracture resistance and fatigue limits of short fiber reinforced Dental Composite Resin
Journal of Prosthetic Dentistry, 2016Co-Authors: Jasmina Bijelicdonova, Sufyan Garoushi, Pekka K Vallittu, Lippo V J LassilaAbstract:Abstract Statement of problem Cycling masticatory loads decrease the strength of particulate filler Composites (PFCs) and initiate the failure process by fatigue. The life expectancy of a Composite Resin restoration under stress remains difficult to predict. Purpose The purpose of this study was to determine the fracture resistance and the compressive fatigue limits (CFL) of anterior crown restorations made of a short-fiber reinforced Composite Resin (SFC), to investigate selected mechanical properties of the material following standard test methods, and to observe their correlation with the CFL. Material and methods Specimens (n=10) were fabricated either from SFC (everX Posterior, GC Corp) or PFC (G-aenial anterior, GC Corp). The properties investigated were flexural strength (FS), compression strength (CS), diametral-tensile strength (DTS), and single-edge-notched-bend fracture toughness (FT) following ISO standards. Fracture resistance was determined by static load (n=10) and the CFL at 10000 cycles was determined using a staircase approach (n=20), both on anterior Composite Resin crowns. The results were analyzed with 1-way ANOVA (α=.05) or 2-way ANOVA (α=.05) followed by a Tukey B post hoc test and the Pearson-correlation analysis. Results The SFC crowns had higher fracture resistance (954 ±121 N) than the PFC crowns (415 ±75 N) ( P P 1/2 ) than the PFC (1.0 ±0.2 MPa·m 1/2 ) (F=69.313, P 2 =0.899; P Conclusions SFC crowns showed good performance under static and fatigue loading. FT was the only in vitro test method that filtered as a clinically relevant parameter.
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short glass fiber reinforced restorative Composite Resin with semi inter penetrating polymer network matrix
Dental Materials, 2007Co-Authors: Sufyan Garoushi, Lippo V J LassilaAbstract:Abstract Objectives The purpose of this study was to investigate the reinforcing effect of short E-glass fiber fillers on some mechanical properties of Dental Composite Resin with interpenetrating polymer network (IPN)-polymer matrix. Materials and methods Experimental Composite Resin was prepared by mixing short fibers (3 mm in length) with a fraction of 22.5 wt% and IPN-Resin 22.5 wt% with silane treated silica filler 55 wt% using high speed mixing machine. Test specimens (2 mm × 2 mm × 25 mm) and (9.5 mm × 5.5 mm × 3 mm) were made from the experimental Composite (FC) and conventional particulate Composite Resin (control, Z250, 3M-ESPE). The test specimens ( n = 6) were either dry stored or water stored (37 °C for 30 days) before the mechanical tests. Three-point bending test was carried out according to ISO 10477 and compression loading test was carried out using a steel ball (O3.0 mm) with speed of 1.0 mm/min until fracture. Degree of monomer conversion (DC %) of both Composites was determined by FTIR spectrometry. Water sorption and solubility of specimens were also measured. Scanning electron microscopy was used to evaluate the microstructure of the Composite. Results ANOVA revealed that experimental fiber Composite had statistically significantly higher mechanical performance of flexural strength (210 MPa) and compressive load-bearing capacity (1881 N) ( p Significance The use of short fiber fillers with IPN-polymer matrix yielded improved mechanical performance compared to conventional restorative Composite.
Sufyan Garoushi - One of the best experts on this subject based on the ideXlab platform.
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mechanical properties fracture resistance and fatigue limits of short fiber reinforced Dental Composite Resin
Journal of Prosthetic Dentistry, 2016Co-Authors: Jasmina Bijelicdonova, Sufyan Garoushi, Pekka K Vallittu, Lippo V J LassilaAbstract:Abstract Statement of problem Cycling masticatory loads decrease the strength of particulate filler Composites (PFCs) and initiate the failure process by fatigue. The life expectancy of a Composite Resin restoration under stress remains difficult to predict. Purpose The purpose of this study was to determine the fracture resistance and the compressive fatigue limits (CFL) of anterior crown restorations made of a short-fiber reinforced Composite Resin (SFC), to investigate selected mechanical properties of the material following standard test methods, and to observe their correlation with the CFL. Material and methods Specimens (n=10) were fabricated either from SFC (everX Posterior, GC Corp) or PFC (G-aenial anterior, GC Corp). The properties investigated were flexural strength (FS), compression strength (CS), diametral-tensile strength (DTS), and single-edge-notched-bend fracture toughness (FT) following ISO standards. Fracture resistance was determined by static load (n=10) and the CFL at 10000 cycles was determined using a staircase approach (n=20), both on anterior Composite Resin crowns. The results were analyzed with 1-way ANOVA (α=.05) or 2-way ANOVA (α=.05) followed by a Tukey B post hoc test and the Pearson-correlation analysis. Results The SFC crowns had higher fracture resistance (954 ±121 N) than the PFC crowns (415 ±75 N) ( P P 1/2 ) than the PFC (1.0 ±0.2 MPa·m 1/2 ) (F=69.313, P 2 =0.899; P Conclusions SFC crowns showed good performance under static and fatigue loading. FT was the only in vitro test method that filtered as a clinically relevant parameter.
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short glass fiber reinforced restorative Composite Resin with semi inter penetrating polymer network matrix
Dental Materials, 2007Co-Authors: Sufyan Garoushi, Lippo V J LassilaAbstract:Abstract Objectives The purpose of this study was to investigate the reinforcing effect of short E-glass fiber fillers on some mechanical properties of Dental Composite Resin with interpenetrating polymer network (IPN)-polymer matrix. Materials and methods Experimental Composite Resin was prepared by mixing short fibers (3 mm in length) with a fraction of 22.5 wt% and IPN-Resin 22.5 wt% with silane treated silica filler 55 wt% using high speed mixing machine. Test specimens (2 mm × 2 mm × 25 mm) and (9.5 mm × 5.5 mm × 3 mm) were made from the experimental Composite (FC) and conventional particulate Composite Resin (control, Z250, 3M-ESPE). The test specimens ( n = 6) were either dry stored or water stored (37 °C for 30 days) before the mechanical tests. Three-point bending test was carried out according to ISO 10477 and compression loading test was carried out using a steel ball (O3.0 mm) with speed of 1.0 mm/min until fracture. Degree of monomer conversion (DC %) of both Composites was determined by FTIR spectrometry. Water sorption and solubility of specimens were also measured. Scanning electron microscopy was used to evaluate the microstructure of the Composite. Results ANOVA revealed that experimental fiber Composite had statistically significantly higher mechanical performance of flexural strength (210 MPa) and compressive load-bearing capacity (1881 N) ( p Significance The use of short fiber fillers with IPN-polymer matrix yielded improved mechanical performance compared to conventional restorative Composite.
Abdulkadir Sengun - One of the best experts on this subject based on the ideXlab platform.
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cytotoxicity evaluation of self adhesive Composite Resin cements by dentin barrier test on 3d pulp cells
European Journal of Dentistry, 2009Co-Authors: Hayriye Esra Ulker, Abdulkadir SengunAbstract:OBJECTIVES The aim of this study was to evaluate the effects of five self-etch Dental Composite Resin cements on the cell viability of bovine Dental papilla-derived cells. METHODS The cytotoxicity of Composite Resin cements (Rely X Unicem Clicker, 3M ESPE; MaxCem; KERR, Panavia F 2.0; Kuraray, BisCem; Bisco and Bistite II DC; Tokuyama) was analyzed in a dentin barrier test device using three-dimensional (3D) pulp cell cultures. A commercially available cell culture perfusion chamber was separated into two compartments by 500 mum dentin disc. The three dimensional cultures placed on a dentin disk held in place by a special biocompatible stainless-steel holder. Test materials were introduced into the upper compartment in direct contact with the cavity side of the dentin disks according to the manufacturer's instructions. Subsequently, the pulpal part of the perfusion chamber containing the cell cultures was perfused with medium (2 ml/h). After an exposure period of 24 h, the cell survival was determined by the MTT assay. Statistical analyses were performed using the Mann-Whitney U-test. RESULTS In dentin barrier test, cell survival was similar with Maxcem and negative control group (P>.05), and all other tested materials were cytotoxic for the three dimensional cell cultures (P>.05). CONCLUSIONS The significance of Composite Resin cements is being more important in dentistry. The cytotoxic potencies demonstrated by these materials might be of clinical relevance. Some Composite Resin cements include biologically active ingredients and may modify pulp cell metabolism when the materials are used in deep cavities or directly contact pulp tissue.
Meifang Zhu - One of the best experts on this subject based on the ideXlab platform.
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polymer grafted hydroxyapatite whisker as a filler for Dental Composite Resin with enhanced physical and mechanical properties
Materials Science and Engineering: C, 2013Co-Authors: Fengwei Liu, Ruili Wang, Yanhua Cheng, Xiaoze Jiang, Qinghong Zhang, Meifang ZhuAbstract:Abstract The objective of this study was to investigate the effect of surface graft polymerization of hydroxyapatite whisker (HW) on physical and mechanical properties of Dental Composite Resin. Poly bisphenol A glycidyl methacrylate (Poly(Bis-GMA)) was grafted onto silanized hydroxyapatite whisker (SHW) via solution polymerization and the amount of the Poly(Bis-GMA) on the surface was effectively controlled by polymerization time. The obtained poly(Bis-GMA) grafted hydroxyapatite whisker (PGHW) with different polymer contents was filled into a Resin matrix respectively, meanwhile the Composites with HW and with SHW served as controls. Monomer conversion was characterized by Fourier transform infrared spectroscopy (FTIR) and volume shrinkage of the Composite Resin was measured with a density tester. Mechanical properties were tested with a universal testing machine. The results indicated that the Composite filled with PGHW-1 h (graft ratio of poly(Bis-GMA): 8.5 wt.%) showed lower shrinkage and better mechanical properties, improving flexural strength by 6.5% and 11.9% compared with SHW filled Composite and HW filled Composite, respectively. However, PGHW with higher graft ratios aggregated seriously and formed defects in the Composite, leading to deterioration of mechanical properties. It was revealed that the poly(Bis-GMA) on the surface of PGHW acted as a functional transition layer and enhanced interfacial compatibility and interaction between whisker and Resin matrix, which facilitated the dispersion of PGHW in the Composite and decreased the Composite shrinkage. Thus, the graft polymerization of Bis-GMA on the surface of filler might be a promising modification method for the fabrication of Dental materials.
Insung Luke Yeo - One of the best experts on this subject based on the ideXlab platform.
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influence of acid ethanol and anthocyanin pigment on the optical and mechanical properties of a nanohybrid Dental Composite Resin
Materials, 2018Co-Authors: Sukhyun Hwang, Shin Hye Chung, Jungtae Lee, Yongtae Kim, Yoo Jin Kim, Insung Luke YeoAbstract:This study investigated the influences of acidity, ethanol, and pigment on the optical properties, microhardness, and surface roughness (Ra) of a nanohybrid Dental Composite Resin. A total of 108 disc-shaped specimens were fabricated using a nanohybrid Dental Composite and allocated into 36 different storage solutions according to the levels of pH (2.0, 3.0, 4.0, and 5.5), ethanol (0%, 20%, and 40%), and anthocyanin pigment (0%, 2.5%, and 12.5%). Measurements of the colorimetric parameter and the amount of color change (ΔE), translucency parameter (TP), microhardness, and surface roughness (Ra) were performed at 24 h (baseline), 1-, 2-, 3-, and 4-weeks. Repeated measures of analysis of variance (ANOVA) with a Tukey honestly significant difference test and Pearson correlation analysis were carried out (α = 0.05). Pigment of 12.5% or 40% ethanol significantly increased the ΔE (P < 0.001, P = 0.048, respectively). Pigment of 2.5% or 12.5% significantly decreased the TP (P = 0.001, P < 0.001, respectively). Microhardness of Composite Resin stored in pH 2.0, 3.0, 4.0 solution was lower than that for pH 5.5 (P < 0.001). Pigment, ethanol, and pH did not influence the Ra. TP change and ΔE, and Ra and ΔE had a significant positive correlation (P < 0.05). In conclusion, pigment and ethanol levels influenced the optical properties and acidity affected the microhardness of Composite Resin.