Division of Operative Dentistry, Department of General Dentistry, University of Tennessee Health Science Center College of Dentistry, Memphis, Tennessee, USA.
Department of Operative Dentistry, Aichi Gakuin University School of Dentistry, Nagoya, Japan.
Microsc Res Tech. 2024 Dec;87(12):2811-2817. doi: 10.1002/jemt.24649. Epub 2024 Jul 14.
To assess the fracture resistance of computer-aided design and computer-aided manufacturing (CAD/CAM) ultratranslucent multilayered zirconia (5Y-YZP) veneers with varying facial thickness. Sixty translucent zirconia veneers were designed and milled using a chairside CAD/CAM system for maxillary central incisors. The butt joint incisal veneer tooth preparations consisted of 1.00 mm incisal reduction, 0.40 mm chamfer margin, and three different facial reductions; 0.50, 0.75, and 1 mm, respectively. The ceramic veneers were cemented to printed resin dies and subjected to thermal cycling. Subsequently, the restorations were loaded with compressive loading force, and fracture occurrences were recorded. Scanning electron microscope (SEM) images of the fractured specimens were captured. The fracture resistance varied among the veneers with different facial thicknesses. Ultratranslucent zirconia veneers with a facial thickness of 1.00 mm exhibited the highest fracture resistance values (742.15 N), followed by those with 0.75 mm facial thickness (673 N). Minimally invasive veneers with 0.50 mm thickness displayed similar fracture resistance as thicker veneers with 0.75 mm. However, veneers with 1.00 mm thickness displayed the highest values. SEM fracture patterns for 0.50 and 0.75 mm display similar and fewer crack lines than 1.00 mm veneers. RESEARCH HIGHLIGHTS: Minimally invasive zirconia veneers exhibit similar fracture resistance to thicker veneers.
评估不同面厚的计算机辅助设计和计算机辅助制造（CAD/CAM）超透明多层氧化锆（5Y-YZP）贴面的抗折能力。使用椅旁 CAD/CAM 系统设计并铣削 60 个上颌中切牙的半透明氧化锆贴面。对接切缘贴面牙预备包括 1.00mm 的切缘预备、0.40mm 的切缘斜面和三种不同的面预备：分别为 0.50mm、0.75mm 和 1mm。陶瓷贴面粘接到打印树脂模具上，并进行热循环。随后，将修复体加载压缩力，并记录断裂发生情况。拍摄断裂标本的扫描电子显微镜（SEM）图像。不同面厚的贴面的抗折能力不同。面厚为 1.00mm 的超透明氧化锆贴面具有最高的抗折强度值（742.15N），其次是面厚为 0.75mm 的贴面（673N）。面厚为 0.50mm 的微创贴面与面厚为 0.75mm 的贴面具有相似的抗折强度，但面厚为 1.00mm 的贴面具有最高的抗折强度值。0.50mm 和 0.75mm 的 SEM 断裂模式显示相似的和比 1.00mm 贴面更少的裂纹线。研究亮点：微创氧化锆贴面的抗折强度与较厚的贴面相似。
