Fracture strength of four-unit Y-TZP FPD cores designed with varying connector diameter.: An in-vitro study
Fracture strength of four-unit Y-TZP FPD cores designed with varying connector diameter.: An in-vitro study
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DOI：
10.1111/j.1365-2842.2007.01770.x
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发表时间：
2007-09-01
影响因子：
2.9
通讯作者：
von Steyern, P. Vult
中科院分区：
文献类型：
--
作者：
Larsson, C.;Holm, L.;von Steyern, P. Vult
据报道，由高强度氧化物陶瓷制成的全瓷固定局部义齿 (FPD) 的临床成功率在 82.5% 至 100% 之间。全陶瓷FPD失效的主要原因是连接器区域的断裂。然而，对于什么连接器尺寸合适还没有达成共识。因此，这项体外研究的目的是比较采用不同连接器直径设计的四单元 Y-TZP FPD 芯的断裂强度。总共 40 个由端基台支撑并具有两个桥体的四单元 FPD 核心是用 Procera((R)) 氧化锆制造的。生产了五组连接器尺寸为 2.0、2.5、3.0、3.5 和 4.0 mm 的 FPD 磁芯。所有 FPD 芯均根据制造商对贴面瓷的建议进行烧制程序、循环预加载、热循环以及最后加载直至断裂。连接器直径每次增加，断裂强度都会显着提高，但 2.0 毫米和 2.5 毫米直径除外，这两种直径的断裂均发生在预载期间。所有 FPD 芯在连接器区域均断裂。在本体外研究的限制范围内，对于长跨度或替换磨牙的全陶瓷氧化锆基 FPD，建议最小直径为 4.0 mm。然而，需要进行临床研究来确定足够的连接器尺寸。
Reported clinical success rates of all-ceramic fixed partial dentures (FPDs) made of high-strength oxide ceramics range between 82.5% and 100%. The main cause of all-ceramic FPD failure is fracture in the connector area. There is, however, no consensus on what connector dimensions are adequate. The aim of this in-vitro study was, therefore, to compare the fracture strength of four-unit Y-TZP FPD cores designed with different connector diameters. A total of 40 four-unit FPD cores supported by end abutments and having two pontics were manufactured in Procera((R)) Zirconia. Five groups of FPD cores with connector dimensions of 2.0, 2.5, 3.0, 3.5 and 4.0 mm were produced. All FPD cores underwent a firing programme according to the manufacturer's recommendations for the veneering porcelain, a cyclic preload, thermocycling and finally, load until fracture. Fracture strength was significantly higher for each increase in connector diameter except for the 2.0-mm and 2.5-mm diameters where all fractures occurred during preload. All FPD cores fractured in the connector area. Within the limitations of this in-vitro study, a minimum diameter of 4.0 mm is recommended for all-ceramic zirconia-based FPDs with long spans or replacing molars. Clinical studies are, however, needed to determine adequate connector dimensions.