Plat铸造陶瓷包埋料的研究

本文介绍了Plat铸造陶瓷专用包埋料的组成成分及有关物理性能,用此包埋料制作铸造陶瓷全冠,考察了铸造陶瓷冠修复体的适合性。结果指出:全冠粘固后边缘浮出量,代型涂隙料组为54/μm,未涂隙料组为269μm。说明用此包埋料,辅以隙料技术,可获得适合性优良、可被临床应用的Plat铸造陶瓷修复体。并推导出所需隙料厚度的公式。     

热铸型陶瓷包埋料的研制和铸造精度的检测

目的 :根据新型热铸型玻璃陶瓷的性能 ,研制出专用包埋材料 ,并对其性能和铸造精度进行检测。方法 :通过组分筛选和工艺合成得出优选配方 ,对包埋料的物理性能进行检测 ;并用研制的包埋料铸造陶瓷全冠 ,用片切法观察代型与全冠之间的粘固膜厚度。结果 :热铸型陶瓷包埋料为石英磷酸盐包埋料 ,凝固时间 8.5 -9min ,凝固膨胀率 2h后为 0 .5 8% ,80 0℃热膨胀率为 0 .78% ,总膨胀率为 1.3 6% ,抗压强度 2 4h后 2 9MPa ,80 0℃焙烧后为 17MPa。代型与陶瓷全冠之间的粘固膜厚度 ,与对照组之间无显著性差异 (P >0 .0 5 )。结论 :热铸型陶瓷专用包埋料具有适宜的凝固时间、膨胀率及抗压强度 ,能够制作出适合性良好的陶瓷修复体。     

包埋料和热处理对自研贵金属合金铸造适合性的影响

目的　比较不同包埋料和热处理方法对牙科铸造贵金属合金BS 1金合金铸件铸造适合性的影响。方法　采用 2种包埋料 (F 1和Z 1包埋料 )包埋模拟后牙冠的帽状代型蜡型 ,用BS 1金合金铸造 ,铸件经过不同的热处理 (软化热处理 ,硬化热处理和恒温时效硬化热处理 )后试合于各自的石膏代型 ,在体视显微镜和金相显微镜下分别测试铸件的边缘适合性和组织面密合度 ,求各自的平均值 ,统计分析各组之间的统计学差异性。结果　F 1包埋料组的边缘差异明显小于Z 1包埋料组 (P <0 0 5 )。热处理对金合金铸件的铸造适合性无显著性影响。结论　BS 1金合金用F 1包埋料包埋铸造的铸件其铸造适合性优于Z 1包埋料组。热处理对其铸造适合性无显著性影响     

热压铸入型玻璃陶瓷材料的初步研制Ⅱ.材料的生物安全性评估

目的 :评估新型热压铸入型玻璃陶瓷材料的生物安全性。方法 :根据ISO标准 ,采用急性全身毒性试验、溶血试验、细胞毒性试验、皮肤刺激试验和口腔粘膜刺激试验对玻璃陶瓷进行评估。结果 :玻璃陶瓷对实验小鼠无全身急性毒性作用 ,溶血指数 1.38% ,细胞生长无明显抑制现象 ,细胞毒性评分为Ⅰ级 ,对皮肤和口腔粘膜无刺激作用。结论 :新型热压铸入型玻璃陶瓷材料具有良好的生物安全性 ,符合临床应用标准。     

2种石膏基包埋料对铸造精度影响的比较研究

目的研究2种商品化包埋料Cristo balite MicroⅡ和Cristo Quick的膨胀性能及其对铸件精度的影响。方法选用传统型石膏基包埋料Cristo balite MicroⅡ和快速加热型石膏基包埋料Cristo Quick,按粉液质量比为1∶3的比例混合调拌,分别测定2种包埋料的凝固膨胀率和热膨胀率。以预制标记点的圆盘形蜡型为铸件原型,采用0.45 mm陶瓷纤维衬层铸圈,分别用2种包埋料包埋铸造,测量铸件在相应标记点方向上的尺寸变化率。结果1）Cristo baliteMicroⅡ的凝固膨胀率、热膨胀率和总膨胀率分别为0.68、1.18和1.86,Cristo Quick则分别为0.94、1.03和1.97。2种材料的凝固膨胀率和热膨胀率的差异有统计学意义（P<0.05）,而总膨胀率的差异无统计学意义（P>0.05）。2）在衬层厚度相同的情况下,采用2种包埋料铸造的铸件,其尺寸变化率的差异无统计学意义（P>0.05）。结论本研究选择的2种石膏基包埋料膨胀量相同但膨胀特性不同,对铸造精度都没有影响。     

快速和慢速包埋方法对铸造冠精度影响的比较研究

目的研究快速和慢速包埋方法对铸造全冠精度的影响。方法在同一模具上制作36个熔模冠,随机分为6组,分别用3个厂家的磷酸盐包埋材料进行快速包埋和慢速包埋。测定各组铸造冠的边缘浮升量。结果慢速包埋组铸造冠的平均边缘浮升量为41.67±3.94μm,快速包埋组铸造冠的平均边缘浮升量为96.63±7.46μm,两组间的差别有统计学意义。结论慢速包埋方法比快速包埋方法制作的铸造冠边缘浮升量小,铸造精度高。     

热压铸入型玻璃陶瓷材料的初步研制：Ⅰ.材料的制备,结构分析？…

目的 对初步研制出的新型热压铸入型玻璃陶瓷材料进行结构分析和性能测试。方法 经组分筛选，合成ＳｉＯ２－ＡｌＯ３－Ｋ２Ｏ－Ｎａ２Ｏ系玻璃陶瓷，应用差热分析仪，Ｘ射线衍射仪，扫描电镜等对材料进行分析和观察。     

快速加热型石膏包埋料对铸造精度影响的研究

目的研究快速加热型石膏包埋料包埋后放置时间对其膨胀及铸件铸造精度的影响。方法选用传统型石膏包埋料CRISTOBALITE P(CBP)、快速加热型石膏包埋料CRISTOBALITE PF(CBPF)和CRISTQUICK20(CQ)。根据包埋料类型及包埋后放置时间不同分组为CBP、CBPF-30、CBPF-60、CQ-20、CQ-40、CQ-60。分别测定各组包埋料的硬化膨胀率和热膨胀率。以六棱柱形状蜡型为铸件原型,应用各组包埋料包埋铸造,测量各组所得铸件的尺寸变化率。结果CBPF-30组、CQ-20组的硬化膨胀率和热膨胀率均小于CBP组。随着包埋后放置时间的延长,CBPF和CQ各组的硬化膨胀率明显增大,热膨胀率逐渐减小。CBPF-30组和CQ-20组包埋料所得铸件的收缩率均大于CBP组。CBPF两组所得铸件的尺寸变化率无差别,CQ3组所得铸件的尺寸变化率无差别。结论在一定限度内适当延长快速加热型石膏包埋料包埋后放置时间对铸件的铸造精度无明显影响。     

热压铸入型玻璃陶瓷材料的初步研制：Ⅱ．材料的生物安全性评估

目的：评估新型热压铸入型玻璃陶瓷材料的生物安全性。方法：根据ISO标准,采用急性全身毒性试验、溶血试验、细胞毒性试验、皮肤刺激试验和口腔粘膜刺激试验对玻璃陶瓷进行评估。结果：玻璃陶瓷对实施小鼠无全身急性毒性作用,溶血指数1．38％细胞生长无明显抑制现象,细胞毒性评分为Ⅰ级,对皮肤和口腔粘膜无刺激作用。结论：新型热压铸入型玻璃陶瓷材料具有良好的生物安全性、符合临床应用标准。     

Repair strength of heat-pressed ceramics

summary The bond strengths of porcelain bonded to porcelain specimens using two different filled resin-based cements were compared by means of notched-disc test specimens. As a control group, unrepaired porcelain test specimens were fractured. Additionally, one group of broken half-repairs was achieved by applying a bonding agent only. The control test specimens had significantly higher fracture strengths (P < 0.05) than the specimens bonded with either bonding agent or resin-based cements. No difference between the resin-based cements was found (P>005).     

Bond strength of ceramics heat-pressed onto three dental alloys

Statement of problem

The press-on-metal (PoM) technique has been used as an alternative fabrication method for metal-ceramic restorations. However, how the PoM technique compares with the conventional porcelain layering (CPL) technique under a variety of conditions is unclear.

Influence of layer and stain firing on the fracture strength of heat-pressed ceramics

summary Fracture strength ( T = torque to initiate fracture; K_IC= fracture toughness) and the fractography of heat-pressed leucite reinforced ceramic (IPS Empress, Ivoclar AG-Schaan, Liechtenstein) were analysed by the notched disc test technique and scanning electron microscopy methodologies. To determine the effects of additional firing schedules on the heat-pressed core ceramic, three groups of specimens were prepared. These groups were heat pressed core, heat-pressed core and simulated stain firing, and heat-pressed core and simulated layer firing. Statistical analysis of both T and K_IC values showed that there was no statistically significant difference between these three groups (P > 0–05). Scanning electron microscopy analysis of the fractured surfaces revealed that crack propagation occurred around some of the leucite particles and also partly and directly through other leucite particles.     

Influence of abutment materials on the resultant color of heat-pressed lithium disilicate ceramics

The purpose of this study was to evaluate the influence of abutment materials on the color of IPS Empress 2 ceramic coping with different thicknesses. Ceramic coping specimens (12.0x12.0x0.8-2.0 mm) were fabricated from IPS Empress 2 material (Ingot-100, n=5/group). Abutment specimens were fabricated from a build-up composite, a gold alloy, or a silver-palladium alloy. Color was evaluated using a colorimeter according to the CIE L*a*b* system. The L*a*b* values of the ceramic coping specimens of different thicknesses on each abutment specimen were measured. Following which, the color difference (deltaE*ab) values between the ceramic coping specimens on various abutment specimens were calculated. Significant differences in deltaE*ab value were observed among different abutment specimens at certain ceramic coping thicknesses (P<0.05). Thus, it was concluded that the color of IPS Empress 2 coping material was influenced significantly by both the thickness of the coping and the color of the abutment material.     

氧化锆桩及核树脂材料对热铸压全瓷材料颜色的影响

目的探讨氧化锆做基底覆盖不同厚度核树脂时,对其表面IPS-Empress2热铸压陶瓷颜色的影响。方法采用不同材料分别制作直径11．65mm的标准件,其中核树脂厚0．5mm（A-05）,1mm（A-10）各5个,氧化锆厚3．5mm黄（Y）、白（Wh）色各5个,A3色Z100复合树脂（D）厚3mm 1个,IPS-Empress2铸瓷（P）厚1．5mm 1个。将铸瓷置于复合树脂和氧化锆表面形成实验试件;将铸瓷置于核树脂和A3色Z100复合树脂表面作为对照试件。分别测量P-A05-Wh试件至P-D试件的色度值CIE L＊、a＊、b＊,计算P-A05-Wh、P-A05-Y试件分别与P-A05-D试件之间的色差值,以及P-A10-Wh、P-A10-Y试件分别与P-A10-D试件之间的色差值,并使用析因方差分析和SNK方差分析法统计色差。结果核树脂厚度为0．5mm和1．0mm时,铸瓷配合核树脂置于氧化锆表面与对照组之间的色差值（AE）均小于平均色差识别阈1．8。随着核树脂标准件厚度的增加,铸瓷色度值的改变逐渐减小。结论白、黄两种颜色氧化锆对配合A3色核树脂的130号1．5mm厚IPS-Empress2全瓷标准件无肉眼可见的颜色影响。随着核树脂厚度的增加,氧化锆对130号IPS-Empress2全瓷标准件颜色的影响逐渐减小。