Fracture strength of minimally prepared all-ceramic CEREC crowns after simulating 5 years of service.
Fracture strength of minimally prepared all-ceramic CEREC crowns after simulating 5 years of service.
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模拟使用 5 年后，最低限度制备的全瓷 CEREC 牙冠的断裂强度。
DOI：
10.1016/j.dental.2013.03.019
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
E. Tsitrou
中科院分区：
文献类型：
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作者：
Nikoleta Skouridou;S. Pollington;M. Rosentritt;E. Tsitrou
方法选择30颗上颌磨牙，分为3组，即传统冠预备组（I组）、微量冠预备组（II组）和咬合贴面预备组（III组），比较传统冠预备和微量冠预备的CAD/CAM全瓷粘结冠疲劳载荷后的强度和断裂方式。使用白榴石增强玻璃陶瓷（IPS Empress CAD）制作冠。使用CEREC InEOS系统（v3.10）进行扫描、设计和铣削。模拟5年的临床使用，并测量冠的断裂强度。数据分析采用单因素方差分析和Kruskal-Wallis检验（α=0.05）。结果：Ⅰ组平均断裂强度为1070 N（±181），Ⅱ组平均断裂强度为1110 N（±222）。单因素方差分析显示，两组间差异无统计学意义（p>0.05）。在第三组中，所有的牙列在TCML过程中出现裂纹，并且没有受到断裂载荷。三个传统设计的冠（组I）和4个最低限度设计的冠（组II）在TCML. SIGNIFICANCE最低限度的全瓷树脂粘结冠的表面裂纹可以潜在地形成一个可行的修复选择，因为他们表现出相当的强度，传统的全瓷冠。然而，这应谨慎解释，因为许多牙冠在模拟使用5年后出现裂纹。所有的咬合贴面在模拟过程中出现裂缝，需要进一步的调查，这被认为是一个可行的选择。
OBJECTIVESTo examine the strength and mode of fracture of traditionally and minimally prepared all-ceramic resin bonded CAD/CAM crowns after fatigue loading.METHODSThirty human maxillary molars were used and divided in three groups namely; traditional crown preparation group (I), minimal crown preparation group (II) and occlusal veneer preparation group (III). A leucite reinforced glass ceramic (IPS Empress CAD) was used for fabricating the crowns. The CEREC InEOS system (v3.10) was used for scanning, designing and milling. Five years of clinical service were simulated and the fracture strength of the crowns was measured. One-way ANOVA and Kruskal–Wallis test were used for data analysis (α=0.05).RESULTSThe mean fracture strength and SD in Group I was 1070N (±181) and in Group II 1110N (±222). One-way ANOVA analysis showed no statistically significant difference between the two groups (p>0.05). In Group III all restorations developed cracks during TCML and were not subjected to fracture loading. Three of the traditionally designed crowns (Group I) and 4 of the minimally designed crowns (Group II) developed surface cracks during TCML.SIGNIFICANCEMinimal all-ceramic resin-bonded crowns can potentially form a viable restorative option as they demonstrated comparable strength to traditional all-ceramic crowns. However, this should be interpreted with caution as a number of crowns showed cracks after 5 years of simulated service. All the occlusal veneers developed cracks during simulation and further investigation is needed for this to be considered a viable option.