Department of Operative Dentistry, Faculty of Oral and Dental Medicine, Delta University for Science and Technology, Gamasa, Egypt.
Department of Operative Dentistry, Faculty of Dentistry, Mansoura University, Mansoura, Egypt.
J Esthet Restor Dent. 2018 May;30(3):229-239. doi: 10.1111/jerd.12364. Epub 2018 Jan 25.
To assess the influence of new light curing lab composite, lithium-disilicate glass-ceramic and yttrium-stabilized zirconia-based ceramic on the fracture resistance of maxillary premolars with class II inlay and onlay preparations.
Seventy sound maxillary premolars were divided randomly into seven main groups. The first group was left intact (control group). The remaining six groups were prepared with inlay and onlay cavities and restored with lab composite (SR Nexco), lithium-disilicate glass-ceramic (IPS e.max Press) and yttrium-stabilized zirconia-based ceramic (ICE Zirkon). The restorations were cemented with luting resin composite (Variolink N). All specimens were thermocycled 5000 cycles between 5°C ± 2°C and 55°C ± 2°C and were then cyclic loaded for 500 000 cycles. The specimens were subjected to a compressive load in a universal testing machine using a metal sphere until fracture occurred. The results were analyzed by 2-way ANOVA and Tukey HSD post hoc tests. The level of significance was set at P < .05.
There were no statistically significant differences among the means of control group and the groups restored with zirconia ceramic inlays and onlays (P > .05). However, statistically significant differences were found among the means of control group and the groups restored with lab composite inlays, lab composite onlays, pressable glass ceramic inlays and pressable glass ceramic onlays (P < .05).
The fracture resistance of prepared teeth for inlay and onlay restorations is inferior to the intact teeth when lab composite is used. Conversely, when a ceramic material being used, the prepared teeth for inlay and onlay restorations showed a comparable strength to the intact teeth especially zirconia ceramic.
Premolar teeth restored with zirconia ceramic inlays and onlays exhibited fracture resistance comparable to intact teeth.
评估新型光固化实验室复合树脂、锂硅玻璃陶瓷和氧化钇稳定氧化锆基陶瓷对 II 类嵌体和高嵌体预备上颌前磨牙抗折性能的影响。
70 颗健康的上颌前磨牙随机分为 7 组。第一组保持完整（对照组）。其余 6 组制备嵌体和高嵌体窝洞，并分别用实验室复合树脂（SR Nexco）、锂硅玻璃陶瓷（IPS e.max Press）和氧化钇稳定氧化锆基陶瓷（ICE Zirkon）修复。所有修复体均用粘固树脂复合树脂（Variolink N）粘固。所有标本均在 5°C±2°C 和 55°C±2°C 之间进行 5000 次热循环，然后进行 500000 次循环加载。在万能试验机上用金属球对标本施加压缩载荷，直至发生断裂。采用 2 因素方差分析和 Tukey HSD 事后检验对结果进行分析。显著性水平设为 P<.05。
与氧化锆陶瓷嵌体和高嵌体修复组相比，对照组和用氧化锆陶瓷修复的嵌体和高嵌体组的平均值之间没有统计学上的显著差异（P>.05）。然而，对照组和用实验室复合树脂嵌体、实验室复合树脂高嵌体、可压玻璃陶瓷嵌体和可压玻璃陶瓷高嵌体修复的组之间的平均值之间存在统计学上的显著差异（P<.05）。
当使用实验室复合树脂时，预备嵌体和高嵌体修复的牙齿的抗折性能低于完整牙齿。相反，当使用陶瓷材料时，预备嵌体和高嵌体修复的牙齿的强度与完整牙齿相当，尤其是氧化锆陶瓷。
用氧化锆陶瓷嵌体和高嵌体修复的前磨牙具有与完整牙齿相当的抗折性能。
