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The Basic Research of A Dental Machinable Ceramic Based on Diatomite

Author: LiuMei
Tutor: ZhangFeiMin
School: Nanjing Medical University
Course: Clinical Stomatology
Keywords: Dental thermal die-cast porcelain Element Microstructure Leucite Machinable ceramics Diatomite Strength
CLC: R783
Type: Master's thesis
Year: 2009
Downloads: 26
Quote: 0
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Abstract

All-ceramic dental restorations has good biocompatibility and aesthetic properties, clinical application is more and more widely. In many of the all-ceramic materials, cutting ceramic combined with computer-aided design and aided manufacturing (computer aided design / computer aided manufacture, CAD / CAM) technology, you can quickly and accurately create restoration and ceramic pre block by manufacturers produced more advantageously control the mechanical properties of materials and aesthetic properties. The introduction of CAD / CAM technology, groundbreaking, revolutionary changes in the oral fixed prosthesis design and production technology, cutting ceramic materials for CAD / CAM technology to provide the material basis of the driving force behind the development of more diverse CAD / CAM . Therefore, the development applicable to oral rehabilitation needs of the low melting point, high strength, high toughness, easy processing of dental cutting ceramic repair of oral science clinical will have important practical value. The topic First select existing thermal die-cast porcelain products on the market Cergo as the object of study, analysis of the chemical composition and the microstructure before and after the sintering, mechanical properties measured before and after the sintering, and thermodynamic analysis to explore the material during sintering substances changes in the relationship between the performance and structure of the study materials, a new machinable Diatomite all-ceramic materials developed to provide a reference. The second portion of the subject of the present invention in the domestic first select celite as raw material, to use its loose frame structure, and by adding the nano toughener to improve the mechanical properties of the material, and explore the sintering process of the material was prepared by a novel dental all-ceramic material cutting diatomaceous earth, its mechanical properties and aesthetic performance in line with the requirements of the all-ceramic dental materials, good cutting performance, and has broad prospects. Ingredients around the first part of the dental heat-pressed ceramic sintering and microstructure analysis purposes to explore the Cergo hot die-cast porcelain material sintering before and after the composition and microstructure, and sintering process on its properties. Full spectrum of direct reading inductively coupled plasma atomic emission spectrometer (inductively coupled plasma ICP) and UV-visible spectrophotometric analysis of the chemical composition of the sintering the Cergo hot die-cast porcelain material, heat / poor heat associated with thermal analyzer (Thermogravimetric / differential The characterization of the sintering process of the thermal analyzer TG / DTA) Cergo hot die-cast porcelain material thermodynamic transformation mechanism, X-ray diffraction (X-ray diffractometer XRD) Cergo hot die-cast porcelain material characterization before and after sintering polymorphs, scanning electron microscopy (scanning electron microscope SEM) surface morphology observed the Cergo thermal die-cast porcelain materials, and test the Cergo sintered before and after the micro-hardness and density as well as three-point bending strength of the sintered. Results Cergo hot die casting Sintering is an amorphous ceramic material containing mainly of SiO ₂, Al, ₂ O ₃, Na < sub> 2 O and K ₂ O, etc. oxide, and which contains nanoscale particles. Sintered samples by X-ray diffraction analysis and scanning electron microscopy, suggesting that precipitation of tetragonal leucite crystals, crystal particle size of approximately 1 ~~ 3μm dense glass matrix. The Cergo sintered microhardness and density are from 4.96 ± 0.27GPa and 2.22 ± screen overflow ^{3 , significantly higher than before sintering 2.00 ± 0.20 GPa and 1.68 ± 0.07 g / cm ^{3 (P lt; 0.05). After sintering a three point bending strength of 76.27 ± 9.40MPa. Conclusions the Cergo hot die-cast porcelain material before sintering in SiO ₂-Al ₂ O ₃-Na ₂ O- K ₂ O as a main component of the glassy material, after high-temperature sintering, solid-phase reaction, the resulting dense tetragonal leucite crystals strengthened glass ceramic. A sintering process of the material comprises a fusion of the glass particles and the crystals precipitated, the precipitation of the crystals so that the mechanical properties of the ceramic can be significantly improved. The second part of the dental cutting diatomaceous earth all-ceramic materials research purposes to develop a new type of dental ceramic materials cutting diatomite, explore the relationship of structure and performance, the research base for the development of a new all-ceramic dental materials. Methods celite-based raw material, in its original formulation, adding nano-zirconium oxide, aluminum oxide and titanium oxide whisker as a toughening agent, in accordance with the dry pressing of milling → → sintering process, the ceramic material was prepared. Using X-ray diffraction (X-ray diffractometer XRD) analysis of ceramic the component crystalline phase, a scanning electron microscope (scanning electron microscope SEM) to observe the microstructure of the ceramic, and to measure the mechanical properties of materials (three-point bending strength, fracture toughness and microhardness). Were prepared by sintering temperature of 600 ° C, 700 ° C, 800 ° C, 900 ° C ceramic material, the evaluation material cutting and screening optimal sintering temperature. Results of the dental cutting diatomaceous earth all-ceramic material surface is smooth, is white, no cracking; electron microscopy inside the material presented dense polycrystalline structure, clear grain boundary less, porosity, no cracks; their three-point bending strength of 177.23 ± 7.02 MPa, microhardness to 9.73 ± 0.64GPa, and fracture toughness of 3.93 ± 0.58MPa · m ^{0.5 . Early sintered ceramic material sintering temperature of 700 ° C and the cutting performance is good. The conclusion that the material meets the dental cutting the mechanical properties of ceramic materials, aesthetics, performance and cutting the basic requirements, but the strength necessary to further improve.}}}

The Basic Research of A Dental Machinable Ceramic Based on Diatomite

Abstract

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