Bioceramics and their application for dental restoration

Abstract

This review article covers the historical development of ceramics, from the beginnings to the present. Feldspar based ceramic biomaterials for veneering metal frameworks, which are based on the jacket porcelain crown, have firmly established themselves in restorative dentistry since the 1970s. Currently, the development of restorative dental materials that can be used to replace metal represents a major challenge. As a result, this review will focus on the latest materials in this field. These materials include glass ceramics as well as high performance sintered ceramics. Glass ceramics exhibit more favourable optical properties, such as translucency and colour, compared with high performance ceramics, while the latter demonstrate high flexural strength and toughness. Both groups of materials have specialised applications in restorative dentistry and are capable of covering all the indications of dental restorations. The two types of materials, that is, glass ceramics and ceramics, have to be processed in accordance with their properties. As a result, the processing techniques, such as moulding, sintering and machining, will be discussed in detail in addition to the properties of the materials. Additional development possibilities for the materials will be presented on the basis of customer/patient needs and the successful long term use of glass ceramics and ceramics. In this context, it is clear that high performance ceramics and layered composites (consisting of high performance ceramics veneered with glass ceramics) offer the best possible solution for indications in the posterior region of the mouth. In contrast, glass ceramics are used to fabricate inlays and onlays for all parts of the jaw. In addition, glass ceramics can be used to fabricate crowns and small bridges to replace anterior dentition.     

电子陶瓷和器件的低温共烧技术

较系统地介绍了电子器件用低温共烧陶瓷(low temperature cofired ceramics,LTCCs)材料,探讨了其工艺中的若干问题。电子器件用低温共烧陶瓷材料包括:玻璃/陶瓷复合材料、结晶化玻璃、晶化玻璃/陶瓷复合材料以及液相烧结陶瓷,其中典型的和最为常用的LTCCs为玻璃/陶瓷(特别是氧化铝)复合材料。正在研究的一些陶瓷介质材料中,Bi基介质材料引起了人们的关注。玻璃/陶瓷复合材料的制备工艺中,应当着重关注和加深了解玻璃的流动性和结晶性、玻璃的起泡、玻璃和陶瓷颗粒间的反应、共烧材料的匹配等问题,从优选材料配方和优化工艺着手,从而获得优质可靠的材质和器件。     

The Ural mineral raw-material base for the ceramics, refractory, and glass industry

Brief information is reported on the promising deposits of clays and kaolins, feldspars and their substituents, quartz minerals, carbonate rocks, pyrophyllites and kyanites, magnesia and magnesia-silicate materials, and many other types of raw materials for the ceramics, glass, and refractories industry.     

Phase-separation engineering in fluorozirconate glass for designing and fabricating of transparent perfluorinate glass ceramic

Perfluorinate glass ceramics with ultra-low phonon energy are very important optical and photonic materials. Unfortunately, there is no suitable method to obtain transparent perfluorinate glass ceramics due to poor thermal stability of fluoride glass. As a result, wide applications of glass ceramics in advanced infrared systems are restricted. Here, an effective method based on phase-separation engineering is used to develop transparent perfluorinate glass ceramics. In this article, a novel transparent Er³⁺-doped ZnZrF₆-Ba₆Zn₇F₂₆ perfluorinate glass ceramic was designed and fabricated by phase-separation engineering. The sample exhibits low phonon energy (564 cm⁻¹), ultra-wide transmission range (0.33–8.2 μm, T ≥ 50 %), and strong infrared emission, which is better than that of ZBLAN glass, oxide-, and oxyfluoride-glass ceramics. These good properties of the perfluorinate glass ceramic demonstrate that phase-separation engineering not only offers an effective approach to obtain perfluorinate glass ceramics but also provides wide-ranging opportunities for advanced infrared optical and photonic materials.     

Characterization of New Categories of Bioactive Based Tellurite and Silicate Glasses

New types of tellurite glass ceramics were prepared and studied from the viewpoint of bioactivity. The obtained results were compared with those of silicate glass ceramics. The crystallization behaviors of both silicate and tellurite glass ceramics with equal ratio of CaO/P₂O₅ were investigated. The silicate glass samples were transformed to glass ceramics by a thermal treatment process. While the tellurite glass ceramics were directly obtained without any thermal treatment. The microstructure of these materials was characterized by X-ray diffraction (XRD), Fourier transform infrared absorption spectroscopy (FTIR) and a scanning electron microscope (SEM) equipped with an energy dispersive spectrometer (SEM/EDX). The results revealed clear proof that TeO₂ promoted the nucleation and crystallization processes which led to the formation of different crystalline bio-phases. While the silicate glasses showed a much lower degree of crystallinity than that presented by the tellurite glass ceramics. The crystals of tellurite containing glass were needle- like morphology, which is attributed to the one-dimensional rapid growth of the apatite-tellurite phase. On the other hand, a particle-like morphology is shown in the silicate glass matrix. Bioactivity of the glasses in simulated body fluids (SBF) was investigated. Tellurite containing glass ceramics showed a better bioactivity during the in vitro test than that of the silicate one. This was attributed to a great analogous between the morphology of crystals of tellurite glass and the morphology of hydroxyapatite in human bone, since both possess a needle-like morphology.     

骨修复用生物玻璃的研究现状及其发展趋势

生物活性玻璃和生物微晶玻璃因其优异的生物活性及组分与性能的可设计性而引起广泛关注，人们力图在此基础上研制出性能优良的骨修复材料。笔者综述了目前生物玻璃及生物微晶玻璃体系、组分及其活性机理，探讨了其在医学领域的应用及其发展趋势。     

Technology of New Materials with Controlled Properties in Integrated Industrial Waste Treatment

A method of industrial waste treatment by melting in a reducing medium with the subsequent separation of the mixture was considered. This method produces x-ray amorphous raw material of constant chemical composition, which contains almost no compounds of iron and other transition metals. The raw material produced can be used to manufacture glass ceramics that are transparent in the visible region and have a low thermal expansion coefficient. Glass ceramics were synthesized that are promising for use as substrates for optical and magneto-optical data storage media, for manufacturing visible and near-IR bandpass filters, and also for producing optical fiber materials. The possibility of obtaining porous materials with different types of crystal structures, low density, and controlled pore size and type was demonstrated.     

Femtosecond laser micro-milling dental glass ceramics: An experimental analysis and COMSOL finite element simulation

Dental glass ceramic materials are widely used in all-ceramic restoration technology. In order to effectively solve the problems existing in the process of traditional diamond cutter milling dental glass ceramic materials, such as severe needle loss, large tool wear and general milling efficiency, a new method of ultrafast laser milling dental glass ceramics is proposed. In this paper, 1030 nm femtosecond laser with pulse width of 600fs was used to micro-mill dental glass ceramics. Confocal laser microscopy was used to measure the milling depth and surface roughness of single-layer milling under selected laser processing parameters. The pre-layered milling software was developed to control the z-axis lifting and to compensate the focal length synchronously. Scanning electron microscope (SEM), Raman spectrometer and Vickers micro-hardness tester were used to characterize the dental glass ceramics after femtosecond laser milling. The results showed that under the specific laser processing parameters, the infrared femtosecond laser milling system can achieve a good processing morphology without changing the surface composition and surface hardness of dental glass ceramics. This new dental glass ceramics processing method based on ultrafast laser technique indicated a new direction for further chair processing of dental all-ceramic restoration technology.     

烧结微晶玻璃的生产及其着色

介绍了烧结微晶玻璃的工艺原理、生产工艺,结合实践着重分析和讨论了烧结微晶玻璃的着色工艺及典型的一次着色微晶玻璃的着色剂种类和着色机理.     

低温封接玻璃的研究现状及发展趋势

低温封接玻璃能在400～700℃的温度范围内,实现玻璃、陶瓷、金属合金乃至各类新型复合材料等的完美连接.随着低温封接玻璃无铅化的推进,目前主流研究主要集中于具有潜在应用背景的磷系、铋系、钒系以及硼系低温封接玻璃.本文综述了近年来国内外关于低温封接玻璃的研制现状以及未来的发展趋势.低温封接玻璃在无铅、低温的大趋势下,未来还需具备一定的导热性能和向复合化方向发展.     

浅谈矿渣微晶玻璃

介绍了国内外矿渣微晶玻璃以工业废渣或冶金采矿尾砂为主要原料,配以其它辅助原料,经熔化、成形、结晶退火等工序而制得微晶玻璃材料的研制和开发概况。并同时简介了采用烧结法、浮法工艺、压延法等工艺方法制造微晶玻璃产品的状况。     

MgO-Al2O3-SiO2系透明玻璃陶瓷研究进展

透明玻璃陶瓷具有热膨胀系数可调、强度高、化学稳定性好的优点,且兼具透光/发光的特性,是一种在光学信息、生物技术、激光技术、红外遥感及民用照明等领域有着广泛的应用前景的新型功能材料。本文简述了玻璃陶瓷的透光机制,对形核剂、过渡金属离子及稀土离子掺杂MgO-Al₂O₃-SiO₂(MAS)系透明玻璃陶的析晶及透光/发光性能方面的研究进展进行了介绍,并简要分析了开发具备透光/发光性质的高结晶度MAS透明玻璃陶瓷材料存在的问题,最后展望了透明玻璃陶瓷的发展趋势与前景。     

Glass Ceramics Based on Oil Shale Ash

The experience of synthesizing glass ceramics of pyroxene composition based on the mineral component formed by pyrogassing of solid types of fuel, in particular, in processing oil shale is generalized. The structure and properties of glass ceramics produced by various molding methods are studied.     

工业固体废弃物在硅酸盐材料中的应用研究与展望

工业固体废弃物在材料领域中的应用非常广泛,这里综述了工业固体废弃物在陶瓷、微晶玻璃、玻璃三种硅酸盐材料中的应用及其研究现状,并对现存的问题提出了一些建议。     

激光玻璃陶瓷的研究进展

简述了激光玻璃陶瓷的主要类别,介绍了其在通讯信息、工业生产、生化医疗、军事等领域的应用,并提出其将来可能成为玻璃或单晶的替代材料。     

Lithium-Bearing Heat-Resistant Ceramics (A Review)

Literature and patent data on the production and use of lithium-bearing heat-resistant ceramics are analyzed; the results of studying the properties of products made of this ceramics are summarized. It is proposed to use the specified ceramics in materials capable of operating under abrupt temperature variations. __________ Translated from Steklo i Keramika, No. 6, pp. 26 – 31, June, 2005.     

Glass enamels for steel and cast-iron articles (Review)

Various types of enamels for steel and cast iron are analyzed. Their chemical compositions and main physicochemical properties are considered. The current state of research in the synthesis of new enamels and improvement of the physicomechanical properties of existing glass enamels is discussed. The possibilities of replacing costly material components in enamels by less expensive and more available materials as well as recycled waste are specified.     

THE MANUFACTURE AND TREATMENT OF GLASS MELTING POTS*

Manufacture of glass melting pots .—The raw materials used, the methods of grinding and mixing the raw clay and grog, and the way in which pots are built and dried are briefly described for the purpose of impressing glass makers with the amount of labor and care involved. At present only one grade of pot is made; but the difficulty of getting a pot suitable for all kinds of glass suggests the desirability of making special grades of pot for use with specified kinds of glass. Proper treatment of pots by the glass maker .—The authors emphasize the importance of gently handling pots and of storing them in a warm and dry place. The precautions to be taken in preheating pots in arches are discussed at length for this is the critical period in the life of the pot. The batch should be properly crushed and mixed and should either be preheated or loaded in gradually; and the furnace temperature should be carefully regulated. It is particularly urged that the technical treatment of pots in the glass be entrusted to a man trained in ceramics and physical chemistry. Arches for heating glass melting pots .—After discussing the usual design the authors suggest improvements as to fire box locations, construction of walls and door, etc.     

Determination of ceramic flaw populations from component strengths

A procedure is outlined for determining the population of flaws in manufactured ceramics from strength measurements of sampled components. The broad applicability of the procedure is demonstrated in a quantitative manner, using strength measurements from a range of ceramic materials (eg, glass, glass-ceramic, single crystal, and polycrystal) with different flaw types (eg, bulk, surface, and edge). The deconvoluted flaw populations are mostly dominated by small flaws with extended large flaw tails and are all in domains of tens of micrometers. The procedure greatly extends the useful information to be gained by ceramics manufacturers and designers from strength distribution measurements and emphasizes the importance of identifying strength-limiting characteristics within a flaw population.     

Production of Glass Ceramics as a Method for Comprehensive Utilization of Chemical Industry Waste

A variant of comprehensive utilization of waste generated at a chemical enterprise in the production of pyroxene glass ceramics is considered. The structure and properties of synthesized glass ceramic materials are investigated.