Veselinova Maya, Diamantopoulou Sofia, Paximada Chariklia, Papazoglou Efstratios
Department of Operative Dentistry, National and Kapodistrian University of Athens, 11527 Athens, Greece.
J Funct Biomater. 2023 Aug 11;14(8):422. doi: 10.3390/jfb14080422.
To evaluate the fracture strength and the failure mode of endodontically treated molars restored with monolithic lithium disilicate and zirconia endocrowns and overlays. A total of 48 extracted mandibular molars were endodontically treated, decoronated 2 mm above the cementoenamel junction and divided into four 12-specimen groups. Group ELD: lithium disilicate endocrowns. Group EZ: monolithic zirconia endocrowns. Group OLD: lithium disilicate overlays. Group OZ: monolithic zirconia overlays. Overlays did not extend in the pulp chamber and endocrowns extended in the pulp chamber 2 mm. After adhesive bonding of the restorations, the specimens were subjected to thermocycling (×5000 cycles) and then to fracture resistance testing at lateral static loading (1 mm/min) at a universal testing machine. The failure mode of the specimens was qualitatively evaluated. Differences in means were compared using with t-tests for independent samples or Mann-Whitney test ( < 0.05). Weibull distribution analysis was also performed. Group ELD showed significantly higher fracture strength than all other groups ( = 0.001), and the highest Weibull modulus. Conclusions: Lithium disilicate endocrowns exhibit higher fracture strength and are more reliable compared to the other types of restorations examined. Endocrowns had more catastrophic failures compared to overlays.
评估经根管治疗的磨牙采用整块式二硅酸锂和氧化锆内冠及覆盖体修复后的断裂强度和失效模式。总共48颗拔除的下颌磨牙经根管治疗后，在牙骨质釉质界上方2毫米处截冠，并分为四个每组12个样本的组。ELD组：二硅酸锂内冠。EZ组：整块式氧化锆内冠。OLD组：二硅酸锂覆盖体。OZ组：整块式氧化锆覆盖体。覆盖体未延伸至髓腔，内冠延伸至髓腔2毫米。修复体粘结后，样本进行热循环（5000次循环），然后在万能试验机上以横向静态加载（1毫米/分钟）进行抗断裂测试。对样本的失效模式进行定性评估。使用独立样本t检验或Mann-Whitney检验（<0.05）比较均值差异。还进行了威布尔分布分析。ELD组显示出比所有其他组显著更高的断裂强度（P = 0.001），且威布尔模量最高。结论：与所检查的其他类型修复体相比，二硅酸锂内冠表现出更高的断裂强度且更可靠。与覆盖体相比，内冠有更多灾难性失效。
