Property of sintering zirconia ceramics that is important for metal-free bridge restoration

烧结氧化锆陶瓷的特性对于无金属牙桥修复很重要

• 批准号: 18592142
• 负责人: TAMAKI Yukimichi
• 金额: $ 2.41万
• 依托单位: Showa University
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 2006
• 资助国家: 日本
• 起止时间: 2006 至 2007
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18592142/
• 关键词: zirconia; CAD; CAM; fit; metal-free restoration; mechanical property; 曲げ強さ; セラミックス; ブリッジ; 適合性

Zirconium oxide (Zirconia: ZrO_2) has been expected as a new ceramics material because metal-free restoration is available in dentistry. However, it is well-known that zirconia contracted with sintering process at the high temperature. Additionally, zirconia was too hard to form the complex design by cutting tool. The purpose of this study was to investigate the marginal and internal fit of CAD/CAM-fabricated zirconia frameworks. Furthermore, mechanical property was also investigated under the storage in the thermal stress with 20, 000 cycle. Single crown copings (A: abutment), three-unit bridge frameworks (APA, P: pontic), four-unit bridge frameworks (APPA), and five-unit bridge frameworks (A_1P_1A_2P_2A_3) were fabricated with raw-stage zirconia blanks using a commercial CAD/CAM system(KATANA[○!R], Noritake Dental Supply Co. Ltd., Aichi, Japan). Crown copings and frameworks were cemented to their respective master abutment models, and thickness of the cement layer was measured at specific measuring points. Marginal and internal fit of both APA and APPA were within clinical acceptance. However, the marginal gap and thickness of the cement layer on the axial surface of the pontic side of APA and APPA were slightly higher than those of the non-pontic side. As for the marginal gap of A_1P_1A_2P_2A_3 framework, it was superior to those of APA and APPA because the center abutment supported the framework to prevent distortion. Consequently, the axis of the abutment portion (A2) of the framework was kept vertical, thereby resulting in an excellent marginal fit for A2. Thus, findings of this study clearly showed that framework design was important to preventing distortion of long frameworks during post-machining sintering. On the other hand, the three point bending strength of zirconia bar after thermal cycling was less than that of bars stored in the atmosphere. Within this limited data, it was suspected that zirconia might be influenced by the storing environment.

氧化锆（Zirconia：ZrO_2）因可用于牙科领域的无金属修复而被期待成为一种新的陶瓷材料，但众所周知，氧化锆在高温下烧结过程中会发生收缩。本研究的目的是研究 CAD/CAM 制造的氧化锆框架的边缘和内部配合。此外，还研究了机械性能。对单冠内冠（A：基台）、三单元桥框架（APA、P：桥体）、四单元桥框架（APPA）和五单元桥在热应力储存下进行了研究。框架 (A_1P_1A_2P_2A_3) 是使用商业 CAD/CAM 系统（KATANA[○!R]，Noritake Dental）用原始阶段氧化锆毛坯制造的Supply Co. Ltd，日本爱知县）将牙冠内冠和框架粘合到各自的主基台模型上，并在特定测量点测量了 APA 和 APPA 的边缘和内部贴合度。然而，APA 和 APPA 桥体侧轴面的边缘间隙和水泥层厚度略高于非桥体侧的边缘间隙。 A_1P_1A_2P_2A_3框架，优于APA和APPA，因为中心基台支撑框架以防止变形，框架的基台部分（A2）的轴线保持垂直，从而导致A2的边缘配合良好。因此，这项研究的结果清楚地表明，框架设计对于防止加工后烧结过程中长框架的变形很重要，另一方面，框架的三点弯曲强度。热循环后的氧化锆棒的含量低于储存在大气中的氧化锆棒，在此有限的数据内，怀疑氧化锆可能受到储存环境的影响。

项目成果

CM/CAMを用いたセラミックブリッジ-各種ブリッジ形態による適合性-

使用 CM/CAM 的陶瓷牙桥 - 与各种牙桥形式的兼容性 -

• 发表时间: 2007
• 作者: 国井 淳

CAD/CAMを用いたセラミックブリッジ

使用 CAD/CAM 的陶瓷桥

• 发表时间: 2007
• 作者: 国井 淳

Effect of Sintering on the Marginal and Internal Fit of CAD/CAM-fabricated Zirconia Frameworks

烧结对 CAD/CAM 制造的氧化锆框架的边缘和内部配合的影响

• 发表时间: 2007
• 作者: Jun; KUNII; Yasuhiro; HOTTA; Yukimichi; TAMAKI; et. al
• 通讯作者: et. al

Effects of Post-sintering on the Axial Surface Fit of CAD/CAM Fabricated Zirconia Frameworks

后烧结对 CAD/CAM 制造氧化锆框架轴向表面配合的影响

• 发表时间: 2007
• 作者: J.KUNII

Form Reproductivity and Conformity of Different Preparation Model Using Developed Digitizing Software

使用开发的数字化软件形成不同制备模型的再现性和一致性

• 发表时间: 2007
• 作者: 堀田 康弘