Department of Dental Materials and Prosthodontics, State University of São Paulo, São José dos Campos, Brazil.
J Prosthodont. 2010 Aug;19(6):471-7. doi: 10.1111/j.1532-849X.2010.00600.x. Epub 2010 Apr 28.
To evaluate the effect of the opaque layer firing temperature and mechanical and thermal cycling on the flexural strength of a ceramic fused to commercial cobalt-chromium alloy (Co-Cr). The hypotheses were that higher opaque layer temperatures increase the metal/ceramic bond strength and that aging reduces the bond strength.
Metallic frameworks (25 x 3 x 0.5 mm(3); ISO 9693) (N = 60) were cast in Co-Cr and airborne-particle abraded (Al(2)O(3): 150 mum) at the central area of the frameworks (8 x 3 mm(2)) and divided into three groups (N = 20), according to the opaque layer firing temperature: Gr1 (control)-900 degrees C; Gr2-950 degrees C; Gr3-1000 degrees C. The opaque ceramic (Opaque, Vita Zahnfabrick, Bad Säckingen, Germany) was applied, and the glass ceramic (Vita Omega 900, Vita Zahnfabrick) was fired onto it (thickness: 1 mm). While half the specimens from each group were randomly tested without aging (water storage: 37 degrees C/24 hours), the other half were mechanically loaded (20,000 cycles; 50 N load; distilled water at 37 degrees C) and thermocycled (3000 cycles; 5 degrees C to 55 degrees C, dwell time: 30 seconds). After the flexural strength test, failure types were noted. The data were analyzed using 2-way ANOVA and Tukey's test (alpha= 0.05).
Gr2 (19.41 +/- 5.5 N) and Gr3 (20.6 +/- 5 N) presented higher values than Gr1 (13.3 +/- 1.6 N) (p= 0.001). Mechanical and thermal cycling did not significantly influence the mean flexural strength values (p > 0.05). Increasing the opaque layer firing temperature improved the flexural bond strength values (p < 0.05). The hypotheses were partially accepted.
Increasing of the opaque layer firing temperature improved the flexural bond strength between ceramic fused to Co-Cr alloy.
评估不透明层烧制温度、机械和热循环对与商用钴铬合金（Co-Cr）熔附陶瓷的弯曲强度的影响。假设是较高的不透明层温度会增加金属/陶瓷的结合强度，而老化会降低结合强度。
将金属框架（25 x 3 x 0.5 毫米 3 ；ISO 9693）（N = 60）铸造为 Co-Cr，并在框架的中心区域（8 x 3 毫米 2 ）进行空气喷丸处理（Al 2 O 3 ：150 微米），然后将其分为三组（N = 20），根据不透明层烧制温度：Gr1（对照）-900°C；Gr2-950°C；Gr3-1000°C。施加不透明陶瓷（Vita Zahnfabrik，Bad Säckingen，德国的 Opaque），然后在其上烧制玻璃陶瓷（Vita Omega 900，Vita Zahnfabrik）（厚度：1 毫米）。每组一半的样本随机进行无老化测试（水储存：37°C/24 小时），另一半则进行机械加载（20000 次循环；50 N 负载；37°C 的蒸馏水）和热循环（3000 次循环；5°C 至 55°C，停留时间：30 秒）。进行弯曲强度测试后，记录失效类型。使用双因素方差分析和 Tukey 检验（alpha=0.05）对数据进行分析。
Gr2（19.41 +/- 5.5 N）和 Gr3（20.6 +/- 5 N）的数值高于 Gr1（13.3 +/- 1.6 N）（p=0.001）。机械和热循环对平均弯曲强度值没有显著影响（p>0.05）。提高不透明层烧制温度提高了陶瓷与 Co-Cr 合金的弯曲结合强度值（p<0.05）。假设部分成立。
提高不透明层烧制温度提高了陶瓷与 Co-Cr 合金的弯曲结合强度。
