Evaluating mechanical properties of resin infused veneer materials
Date
2015
DOI
Authors
Abuzinadah, Samar Hatem
Version
OA Version
Citation
Abstract
Objectives: The objectives of this study were to investigate the mechanical properties including flexural strength and hardness of resin-infused ceramic and to compare it to feldspathic porcelain and commercially available composite resin products, and to investigate the effect of thermocycling and cyclic fatigue on flexural strength of resin-infused ceramic, feldspathic porcelain and composite resin and to test their abrasion resistance against vita MKII.
Materials: RIC ceramic powder and Enamic Vita dry pressed blocks were used in this study. Diurethane dimethacrylate and silane solution were used for fabricating resin-infused ceramics. For biaxial flexural strength, thermocycling and cyclic fatigue testings, discs cut out of blocks were made from resin-infused RIC, resin-infused Enamic, Vita blocks MKII, Paradigm MZ100, and Lava Ultimate Paradigm. One of the specimens from a biaxial flexure strength test of each material was tested for knoop microhardness, while bars cut out of blocks were used for wear testing.
Methods: Die-pressed porous ceramic blocks were prepared from RIC ceramic powder. The blocks were sintered at different temperatures and density was measured. The porous ceramic blocks were infused with UDMA (Diurethane dimethacrylate), TEGDMA (Triethylene glycol dimethacrylate), and BP (Benzoyl Peroxide) resin mixture under vacuum condition. The polymerized resin-infused ceramic blocks were smoothed into round cylinders and cut into disc-shaped specimens (13x2 ±2 mm) and subjected to biaxial flexural strength test. They were also cut into bar-shaped specimens (21x13x2 ± 2 mm) and subjected to wear test using Pin-on-Plate wear mach ine. Fragments from biaxial flexural strength test were used for knoop microhardness using a Buehler Micromat 2003 microhardness (Manufacturer, location) indenter. Specimens were categorized into two main ceramic groups (RIC and Enamic mono) and two main composite resin groups (MZl00 Paradigm and Lava Ultimate Paradigm). In the Enamic resin infused group, there were two subgroups, one vita resin infused and one resin infused at BU lab. For a study of thermocycling effect, specimens were thermocycled between water temperature of S°C and 55°C in a custom fabricated thermocycling machine. After being thermocycled, specimens were subjected to cyclic fatigue to test their fracture toughness then to biaxial flexural strength test. Another group of specimens were only subjected to a cyclic fatigue test then to biaxial flexural strength test without thermocycling. The data were analyzed using one-way ANOVA and Tukey multiple comparisons.
Results and Conclusions: In the Biaxial flexural strength test, Paradigm MZl00 had the highest mean biaxial flexural strength (219.86 ± 30.31 MPa), followed by Paradigm Lava Ultimate (165.20 ± 27.37 MPa), RIC post-sintering density 1.75g/ mm 3 (160.59 ± 9.76 MPa), RIC post-sintering density 1.6 g/ mm3 (149.17 ± 11.16 MPa), Vita MKII (126.67 ± 7.82MPa), experimental Vita resin-infused Enamic (126 ± 11.77 MPa), and experimental BU lab resin-infused Enamic (121.91 ± 9.82 MPa) materials. Thermocycling plus cyclic fatigue had a statistically significant effect on the biaxial flexural strength of the materials with no difference observed between cyclic fatigued groups without thermocycling. In the Knoop microhardness test, RIC post-sintering density 1.75 g/ mm3 recorded the highest mean hardness (240 ± 18.57 HK), followed by Vita MKII (232.80 ± 15.04 HK), experimental Vita resin-infused Enamic (219.10 ± 20.73 HK), experimental BU lab resin-infused Enamic (195 ± 8.24 HK), RIC post-sintering density 1.6g/ mm3 ( 175.59 ± 13.89 HK), Paradigm MZ100 (109.82 ± 6.34), and Paradigm Lava Ultimate (96.67 ± 4.74 HK) materials with statistically significant higher hardness values of ceramics over composites and no statistically significancant difference between Paradigm MZ100 and Paradigm Lava Ultimate. In the pin-on-plate abrasion test, Vita Mark II and resin-infused Enamic demonstrated wear that was significantly higher than all other materials tested (RIC, and composite MZ100 Paradigm and composite Lava ultimate Paradigm) significantly when they were abraded by the same type of ceramic over a long span (39 mm length) regardless of resin infusion RIC material scored scoring the lowest volume loss among this travel span. However, when Vita Mark II and resin infused Enamic were abraded over a short span (15 mm wear groove length) they gave comparable results to the other materials were obtained; with resin-infused Enamic scoring the lowest wear values.
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Dissertation (DScD)--Boston University, Henry M. Goldman School of Dental Medicine, 2015 (Department of Restorative Sciences and Biomaterials)
Includes bibliographic references: leaves 235-247.
Dissertation (DScD)--Boston University, Henry M. Goldman School of Dental Medicine, 2015 (Department of Restorative Sciences and Biomaterials)
Includes bibliographic references: leaves 235-247.
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This work is protected by copyright. Downloading is restricted to the BU community. If you are the author of this work and would like to make it publicly available, please contact open-help@bu.edu.