Assistant Professor, Department of Restorative Dental Sciences, College Of Dentistry, King Saud University, Riyadh, Saudi Arabia.
J Prosthodont. 2020 Jan;29(1):26-33. doi: 10.1111/jopr.12929. Epub 2018 Jul 2.
To evaluate the influence of various Y-TZP thicknesses and veneer firing cycles on the strength of two ceramic veneers.
180 Y-TZP cores of 0.5, 1.0, and 5.0 mm thickness were prepared followed by sintering in a high temperature furnace; 180 presintered veneering ceramic discs (Vita VM9 porcelain and e.max Ceram) were also prepared using a mold. The discs were placed on zirconia plates (zirconia cores) of different thickness (0.5, 1.0, and 5.0 mm) and exposed to different firing cycles (Vita VM9 porcelain-910, 930, and 950°C; e.max Ceram-750, 770, and 790°C). Ball-on-three-balls flexural strength test was performed (universal testing machine) at a crosshead speed of 0.5 mm/min. Scanning electron microscopy of fractured specimens was performed. Means and standard deviations of flexural strength were analyzed using Tukey-Kramer HSD test for multiple comparisons.
Specimens within material groups showed no significant difference (p > 0.05) for flexural strength with respect to Y-TZP core thickness (0.5, 1.0, and 5.0 mm) (VM9 [117.30 ± 14.328, 117.75 ± 13.66, 113.75 ± 20.10], e.max Ceram [94.79 ± 17.5, 100.02 ± 14.7, 95.23 ± 15.4]). Flexural strength within material groups with respect to different firing cycles ([VM9-910, 930, 950°C], e.max Ceram [750, 770, 790°C]), for VM9 (111.49 ± 15.7, 120.86 ± 13.2, 116.46 ± 18.4), and e.max Ceram (94.64 ± 15.2, 101.6 ± 16.69, 93.8 ± 15.20) showed no significant difference (p > 0.05).
Different zirconia thicknesses (0.5, 1.0, and 5.0 mm) and veneer firing cycles for Vita VM9 and e.max ceramics failed to show any significant influence on their biaxial flexural strengths.
评估不同 Y-TZP 厚度和贴面烧制循环对两种陶瓷贴面强度的影响。
制备 180 个 0.5、1.0 和 5.0 毫米厚的 Y-TZP 核，然后在高温炉中烧结；使用模具还制备了 180 个预烧贴面陶瓷盘（Vita VM9 瓷和 e.max Ceram）。将这些圆盘放置在不同厚度（0.5、1.0 和 5.0 毫米）的氧化锆板（氧化锆核）上，并暴露在不同的烧制循环（Vita VM9 瓷-910、930 和 950°C；e.max Ceram-750、770 和 790°C）下。在 0.5 毫米/分钟的十字头速度下进行球对三球弯曲强度测试（万能试验机）。对断裂标本进行扫描电子显微镜检查。使用 Tukey-Kramer HSD 测试对多个比较进行弯曲强度均值和标准差分析。
在 Y-TZP 核厚度（0.5、1.0 和 5.0 毫米）方面，材料组内的标本在弯曲强度方面没有显示出显著差异（p>0.05）（VM9[117.30±14.328、117.75±13.66、113.75±20.10]，e.max Ceram[94.79±17.5、100.02±14.7、95.23±15.4]）。在不同的烧制循环（[VM9-910、930、950°C]，e.max Ceram[750、770、790°C]）方面，材料组内的弯曲强度，对于 VM9（111.49±15.7、120.86±13.2、116.46±18.4）和 e.max Ceram（94.64±15.2、101.6±16.69、93.8±15.20），没有显示出显著差异（p>0.05）。
不同的氧化锆厚度（0.5、1.0 和 5.0 毫米）和 Vita VM9 和 e.max 陶瓷的贴面烧制循环对其双轴弯曲强度没有显示出任何显著影响。
