• 主页
  • 查找结果
  • Comparison of fracture resistance and fracture characterization of bilayered zirconia/fluorapatite and monolithic lithium disilicate all ceramic crowns.

Comparison of fracture resistance and fracture characterization of bilayered zirconia/fluorapatite and monolithic lithium disilicate all ceramic crowns.

The international journal of esthetic dentistry (2014-04-24)
Abdulaziz M Altamimi, Aris Petros Tripodakis, George Eliades, Hiroshi Hirayama
摘要

To compare the fracture resistance between bilayered zirconia/ fluorapatite and monolithic lithium disilicate heat-pressed crowns and characterize the mode of fracture failure. Thirty crown samples were sequentially fitted on a mandibular right first molar metal replica of an ivory prepared molar tooth. The crown specimens were divided in three groups (A, B, and C; n = 10 for each group). Group A consisted of bilayered zirconia/fluorhapatite pressed-over crowns with standard design crown copings (0.7 mm uniform thickness), Group B of bilayered zirconia/fluorhapatite with anatomical design crown copings, and Group C of lithium disilicate monolithic crowns. The samples were then dynamically loaded under water for 100,000 cycles with a profile of 250 N maximum load at 1,000 N/s rate and 2.0 Hz frequency. Loading was performed with a steel ball (5 mm in diameter) coming into contact with the test crown, loading to maximum, holding for 0.2 s, unloading and lifting off 0.5 mm. The samples were then fractured under static loading, in order to determine the ultimate crown strength. Analysis of the recorded fracture load values was carried out with one-way analysis of variance (ANOVA) followed by Tukey tests. Fractured specimens were examined by stereomicroscopy and scanning electron microscopy. The fracture loads measured were (N, means and standard deviations): Group A: 561.87 (72.63), Group B: 1,014.16 (70.18) and Group C: 1,360.63 (77.95). All mean differences were statistically significant (P < 0.001). Catastrophic fractures occurred in Group C, whereas mainly veneer fractures were observed in Groups A and B. In the present study, the heat-pressed monolithic lithium-disilicate crowns showed more fracture resistance than zirconia/fluorapatite pressed-over crowns. Within the bilayered groups, the anatomical zirconia coping design presented increased ceramic fracture resistance.

材料
货号
品牌
产品描述

Sigma-Aldrich
水, Nuclease-Free Water, for Molecular Biology
Sigma-Aldrich
水, suitable for HPLC
Sigma-Aldrich
水, sterile-filtered, BioReagent, suitable for cell culture
Sigma-Aldrich
水, HPLC Plus
Supelco
水, suitable for ion chromatography
Sigma-Aldrich
水, deionized
Sigma-Aldrich
水, for molecular biology, sterile filtered
Sigma-Aldrich
水, for embryo transfer, sterile-filtered, BioXtra, suitable for mouse embryo cell culture
Sigma-Aldrich
氧化锆 (IV), powder, 5 μm, 99% trace metals basis
纯水密度标准物质RM, 0.9982 g/mL(20 °C), UKAS ISO/IEC17025 and ISO Guide 34 certified, density: 0.9982 g/mL at 20 °C, density: 0.9970 g/mL at 25 °C
Supelco
水, for TOC analysis
Supelco
水, ACS reagent, for ultratrace analysis
Sigma-Aldrich
水, BioPerformance Certified
Sigma-Aldrich
水, PCR Reagent
Sigma-Aldrich
氧化锆 (IV), nanopowder, <100 nm particle size (TEM)
Sigma-Aldrich
E-Toxate 水, endotoxin, free
Sigma-Aldrich
水, for cell biology, sterile ultrafiltered
Sigma-Aldrich
锆, powder, −100 mesh
Supelco
密度标准品 998kg/m3, H&D Fitzgerald Ltd. Quality
Sigma-Aldrich
低氘水, ≤1 ppm (Deuterium oxide)
Sigma-Aldrich
水, ACS reagent
Sigma-Aldrich
水, tested according to Ph. Eur.
Sigma-Aldrich
锆, foil, thickness 0.1 mm, 99.98% trace metals basis
Supelco
水, for HPCE, for luminescence, suitable for UV/Vis spectroscopy
Sigma-Aldrich
氧化锆 (IV), 99.99% trace metals basis (purity excludes ~2% HfO2)
Sigma-Aldrich
氧化锆(IV), nanoparticles, dispersion, <100 nm particle size (BET), 5 wt. % in H2O
水, UKAS ISO/IEC17025 and ISO Guide 34 certified, density: 0.9982 g/mL at 20 °C, density: 0.9970 g/mL at 25 °C
Sigma-Aldrich
锆, sponge, ≥99% trace metals basis
Sigma-Aldrich
锆, rod, diam. 6.35 mm, ≥99% trace metals basis
Sigma-Aldrich
水-16O, ≥99.94 atom % 16O

社交媒体

LinkedIn icon
Twitter icon
Facebook Icon
Instagram Icon

Merck

科研、开发、生产。

作为生命科学行业的全球领先供应商,我们致力于为科研、生物技术开发和生产,以及制药药物疗法开发和生产提供各类解决方案和服务。

© 2021年版权归德国达姆施塔特默克集团(Merck KGaA)及/或其附属公司所有。版权所有。

未经许可,严禁复制本网站上的任何资料。