Mohamed Omar, Kim Hyeongil, Makowka Steven, AlMozayen Ahmed, Sawangsri Kedith, Li Rui
Assistant Professor, University of Alabama at Birmingham, School of Dentistry, Birmingham, AL.
Associate Professor, Restorative Dentistry Department, University at Buffalo School of Dental Medicine, Buffalo, NY.
J Prosthet Dent. 2025 Jan;133(1):280.e1-280.e6. doi: 10.1016/j.prosdent.2024.09.030. Epub 2024 Oct 29.
Speed sintering techniques have been introduced to shorten the sintering time of zirconia ceramics, yet their impact on multilayered zirconia properties remains understudied.
The purpose of this in vitro study was to assess the effect of speed sintering on the optical properties and the mechanical flexural strength of multilayered zirconia materials.
A total of 360 disks (Ø14 ±2 mm ×1.2 ±0.02 mm) were fabricated by following the International Organization for Standardization (ISO) 6872:2015 standard using 2 types of Vita A2 shade multilayered zirconia materials: IPS e.max ZirCAD Prime (ZP) and IPS e.max ZirCAD Prime Esthetic (ZPE). Each material comprised translucent (Tr), gradient l (Gr), and dentin (De) layers, with 60 disks per layer. Half were sintered using a standard sintering protocol and half using a speed sintering protocol. Biaxial flexural strength was accessed using a universal testing machine equipped with the Blue Hill Universal software program by following the ISO 6872:2015 standard, with 20 disks per subgroup. The spectrophotometric analysis of optical properties (contrast ratio [CR], translucency parameter [TP], and total transmittance [Tt%]) was performed using a dual-beam spectrophotometer (Ultrascan VIS) in accordance with the ISO 7491:2000 standard, with 10 disks per subgroup. The comparison of the optical properties and the mechanical flexural strength between the speed and standard protocol was analyzed using an unpaired t test (α=.05).
Speed sintering reduced biaxial flexural strength in all ZP layers (P<.05) and in ZPE-Gr (P<.05). A statistically significant difference in the CR was observed in the ZP-Tr, ZP-Gr, and ZPE-Gr layers (P<.05). The TP of the ZP-Gr, ZP-De, and ZPE-Gr layers was significantly lower when using the speed sintering protocol. Tt% was significantly lower with speed sintering for both materials (P<.05).
Speed sintering statistically changed both the optical (CR, TP, Tt%) and mechanical (flexural strength) properties of multilayered zirconia materials, but the differences may not be clinically relevant.
已引入快速烧结技术以缩短氧化锆陶瓷的烧结时间，但其对多层氧化锆性能的影响仍研究不足。
本体外研究的目的是评估快速烧结对多层氧化锆材料光学性能和机械弯曲强度的影响。
按照国际标准化组织（ISO）6872:2015标准，使用2种维他A2色多层氧化锆材料制作总共360个圆盘（直径14±2毫米×1.2±0.02毫米）：IPS e.max ZirCAD Prime（ZP）和IPS e.max ZirCAD Prime Esthetic（ZPE）。每种材料包括半透明（Tr）、渐变1（Gr）和牙本质（De）层，每层60个圆盘。一半使用标准烧结方案烧结，另一半使用快速烧结方案烧结。按照ISO 6872:2015标准，使用配备Blue Hill Universal软件程序的万能试验机测定双轴弯曲强度，每个亚组20个圆盘。根据ISO 7491:2000标准，使用双光束分光光度计（Ultrascan VIS）对光学性能（对比度[CR]、半透明度参数[TP]和总透光率[Tt%]）进行分光光度分析，每个亚组10个圆盘。使用不成对t检验（α=0.05）分析快速烧结和标准方案之间光学性能和机械弯曲强度的比较。
快速烧结降低了所有ZP层（P<0.05）和ZPE-Gr层（P<0.05）的双轴弯曲强度。在ZP-Tr、ZP-Gr和ZPE-Gr层中观察到CR有统计学显著差异（P<0.05）。使用快速烧结方案时，ZP-Gr、ZP-De和ZPE-Gr层的TP显著降低。两种材料在快速烧结时Tt%均显著降低（P<0.05）。
快速烧结在统计学上改变了多层氧化锆材料的光学性能（CR、TP、Tt%）和机械性能（弯曲强度），但这些差异可能与临床无关。
