Decreasing in sintering temperature and improvement in abrasion properties of dental porcelains

降低烧结温度并改善牙瓷的耐磨性能

基本信息

批准号：
10671852
负责人：
BAN Seiji
金额：
$ 2.05万
依托单位：
Aichi-Gakuin University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10671852/
关键词：
dental porcelain abration sintering temperature leucite glass thermal expansion 歯科用陶材焼成温度摩耗特性

项目摘要

X-ray diffractometry (XRD) was used to analyze the crystal phases of three commercial dentin and incisal porcelains prepared by normal cooling, quenching in water, and controlled slow annealing after normal firing. The results suggest that the cooling condition has little effect on the microstructural changes of leucite crystals in the dental porcelains, since the leucite crystals were formed at a higher temperature range than the firing - and cooling- temperature range and were stabilized by incorporation of additives into the lattice.The leucite crystals having modified compositions from stoichiometric one were prepared by the incorporation of Na, Rb, Cs, Ca, Ba, and Sb substituted for 5 -50 at% of K in the leucite. The lattice parameters of a- and c-axes of these tetragonal leucite were derived from the diffraction angles of (400) and (004) peaks due to tetragonal leucite, respectively. It is concluded that the crystal lattice of leucite was deformed by the incorporation of cations … More substituted for K and their variations mainly depend upon the kind of cation, namely ionic size and substitution site in the lattice.Thermal expansion coefficients were determined using a dilatometer on commercial dental porcelains, stoichiometric tetragonal leucite, cesium added cubic leucite, three kinds of glasses, and mixtures of leucite and glass. Thermal expansion coefficients of leucite were also derived from the lattice parameter changes using high temperature X-ray diffractometry. The results suggested that the glass surrounded around leucite particles is required to have a high glass transformation temperature than 650℃ because of the remains of high stress in the surrounded matrix glass.The influences of cubic leucite having various contents, particle sizes, and firing conditions on various properties (biaxial flexure strength, Vicker's hardness, thermal expansion, and abrasion of human enamel) of dental porcelains were investigated. FE-SEM and XRD analyzes revealed that cubic leucite was changed to tetragonal leucite on the boundary between cublic leucite particle and glass matrix by firing. There were no significant differences in the biaxial flexure strengths of the experimental porcelains containing different content of cubic leucite (p<0.05). It is concluded that the flexure strength of feldspathic dental porcelains was independent on the dispersion of cubic leucite, but depended on the dispersion of tetragonal leucite. Vicker's hardness values of the fired specimens containing cubic leucite increased with the particle size of cubic leucite. Thermal expansion coefficient of the fired specimens containing cubic leucite increased with their contents. Contents of cubic leucite had little effect on abrasion rate. Less

X射线衍射测量法（XRD）用于分析通过正常冷却，在水中淬灭的三个商业牙本质和切口瓷器的晶体阶段，并在正常射击后受控缓慢退火。结果表明，冷却条件对牙瓷中白细胞晶体的微观结构变化几乎没有影响，因为亮氨酸晶体在温度范围更高的温度范围内形成，而不是放电和冷却温度范围，并且通过将Na和cain in Na的白细胞晶体纳入晶状体中，并通过稳定稳定。 5 -50在亮石中的K％。这些四方亮石的A-和C轴的晶格参数分别来自（400）和（004）峰的衍射角，分别是由于四方亮石而引起的。 It is concluded that the crystal Lattice of leucite was deformed by the corporation of cations … More substituted for K and their variations mainly depend upon the kind of cation, namely ionic size and substitution site in the lattice.Thermal expansion coefficients were determined using a dilatometer on commercial dental porcelains, stoichiometric tetragonal leucite, cesium added cubic leucite, three kinds of玻璃杯和亮矿和玻璃的混合物。使用高温X射线衍射法的变化，也从晶格参数变化中得出了亮岩的热膨胀系数。 The results suggested that the glass surrounding around leucite particles is required to have a high glass transformation temperature than 650℃ because of the remainder of high stress in the surrounding matrix glass.The influences of cubic leucite having various contents, particle sizes, and firing conditions on various properties (biaxial flexure strength, Vicker's hardness, thermal expansion, and Abrasion of human enamel) of dental porcelains were investigated. FE-SEM和XRD分析表明，通过射击，Cutic Leucite更改为Cubic Leucite颗粒和玻璃基质之间边界上的四方亮石。实验瓷器的双轴弯曲强度没有显着差异，其中包含不同含量的立方叶丁酸（p <0.05）。独立于立方亮石的分散体，但取决于四方亮石的分散。维克（Vicker）的硬度值含有立方亮石的燃料标本随着立方亮矿的粒径增加。含有立方亮岩的燃料标本的热膨胀系数随着其内容而增加。立方亮石的含量对磨损率几乎没有影响。较少的