The Effect of Preparation Design on the Fracture Resistance of Zirconia Crown Copings (Computer Associated Design/Computer Associated Machine, CAD/CAM System)
The Effect of Preparation Design on the Fracture Resistance of Zirconia Crown Copings (Computer Associated Design/Computer Associated Machine, CAD/CAM System)
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制备设计对氧化锆冠冠抗折性能的影响（计算机关联设计/计算机关联机器、CAD/CAM系统）
DOI：
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发表时间：
2011
期刊：
影响因子：
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通讯作者：
R. Rostami
中科院分区：
文献类型：
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作者：
E. Jalalian;B. Atashkar;R. Rostami
目的全瓷修复体存在的主要问题之一是在咬合力的作用下易发生断裂。本体外研究的目的是比较两种边缘设计（倒角和肩台）对氧化锆冠CERCON（CAD/CAM）抗断裂性的影响。材料与方法本体外研究采用单盲实验技术进行。使用铣床制备具有50 ′倒角终止线设计（0.8mm深度）的不锈钢染料。制备了10种环氧树脂染料，回收相同的染料，将50 ′倒角转化为肩部（1 mm），再由肩部染料制备10种环氧树脂染料。在牙科实验室中，在20个环氧树脂染料（10个样品倒角和10个样品肩部）上制造0.4 mm厚和35 μ m骨水泥间距的氧化锆核。然后将氧化锆芯粘结在环氧树脂染料上，并用通用试验机（GOTECH AI-700LAC，Arson，USA）进行断裂试验，并从失效起源的角度对样品进行研究。结果肩缘抗折强度平均值为788.90 ± 99.56N，倒角缘抗折强度平均值为991.75 ± 112.00N。学生T检验显示组间差异具有统计学意义（P = 0.001）。结论氧化锆核的边缘设计对其抗折强度有影响。倒角边缘可以改善后牙单氧化锆冠修复的生物力学性能。这可能是因为倒角边缘的整体性强，内角圆。
Objective One of the major problems of all ceramic restorations is their probable fracture against the occlusal force. The aim of the present in-vitro study is was to compare the effect of two marginal designs (chamfer & shoulder) on the fracture resistance of zirconia copings, CERCON (CAD/CAM). MATERIALS AND METHODS This in vitro study was done with single blind experimental technique. One stainless steel dye with 50′ chamfer finish line design (0.8 mm depth) was prepared using milling machine. Ten epoxy resin dyes were made, The same dye was retrieved and 50′ chamfer was converted into shoulder (1 mm).again ten epoxy resin dyes were made from shoulder dyes. Zirconia cores with 0.4 mm thickness and 35 μm cement Space fabricated on the 20 epoxy resin dyes (10 samples chamfer and 10 samples shoulder) in a dental laboratory. Then the zirconia cores were cemented on the epoxy resin dyes and underwent a fracture test with a universal testing machine (GOTECH AI-700LAC, Arson, USA) and samples were investigated from the point of view of the origin of the failure. RESULT The mean value of fracture resistance for shoulder margins were 788.90±99.56 N and for the chamfer margins were 991.75±112.00 N. The student’s T-test revealed a statistically significant difference between groups (P=0.001). CONCLUSION The result of this study indicates that marginal design of the zirconia cores effects on their fracture resistance. A chamfer margin could improve the biomechanical performance of posterior single zirconia crown restorations. This may be because of strong unity and round internal angle in chamfer margin.