Hinckfuss Simon, Wilson Peter R
School of Dental Science, University of Melbourne, Victoria, Australia.
J Prosthodont. 2008 Aug;17(6):456-61. doi: 10.1111/j.1532-849X.2008.00324.x. Epub 2008 Jun 9.
The purpose of this study was to evaluate the fracture resistance of bovine teeth restored with one-piece cast core/crowns and no ferrule, compared to teeth restored with amalgam cores and full coverage crowns, with and without a dentine ferrule.
Thirty bovine incisors were selected and modified to ensure all teeth had axial dentine walls of similar size. The teeth were then randomly allocated to one of the three groups: control group restored with amalgam core and cast crown without ferrule; ferrule group restored with amalgam core and cast crown with a 2-mm dentine ferrule; one-piece group restored with one-piece cast core/crown without ferrule. Each tooth was loaded to the point of fracture.
The mean load resisted by the control group, the ferrule group, and the one-piece group were 1092.5, 1843.5, and 1463.1 N, respectively. The mean load resisted by the ferrule group was significantly greater than the control group (p < 0.001) and the one-piece cast core/crown group (p= 0.04). The mean load resisted by the one-piece cast core/crown group was significantly greater than the control group (p= 0.04).
The maximum load resistance was significantly enhanced by a 2-mm ferrule compared with teeth with no ferrule and teeth restored with one-piece cast core/crowns. Teeth restored with one-piece cast core/crowns were significantly more resistant to loading than teeth restored with amalgam cores and crowns without a ferrule.
本研究的目的是评估与用汞合金核和全冠修复的牙齿相比，用一体式铸造核/冠且无箍带修复的牛牙的抗折性，后者修复的牙齿有或没有牙本质箍带。
选择30颗牛切牙并进行改良，以确保所有牙齿具有相似尺寸的轴向牙本质壁。然后将牙齿随机分配到三组中的一组：对照组用汞合金核和无箍带的铸造冠修复；箍带组用汞合金核和有2毫米牙本质箍带的铸造冠修复；一体式组用无箍带的一体式铸造核/冠修复。对每颗牙齿加载直至折断。
对照组、箍带组和一体式组的平均抗载力分别为1092.5、1843.5和1463.1牛。箍带组的平均抗载力显著高于对照组（p < 0.001）和一体式铸造核/冠组（p = 0.04）。一体式铸造核/冠组的平均抗载力显著高于对照组（p = 0.04）。
与无箍带的牙齿和用一体式铸造核/冠修复的牙齿相比，2毫米的箍带显著提高了最大抗载力。用一体式铸造核/冠修复的牙齿比用汞合金核和无箍带的冠修复的牙齿对加载的抵抗力显著更强。
