Department of Prosthodontics, Faculty of Dental Medicine, "Victor Babes" University of Medicine and Pharmacy, Revolutiei Ave. 1989, No. 9, 300580, Timișoara, Romania.
TADERP Research Center-Advanced and Digital Techniques for Endodontic, Restorative and Prosthetic Treatment, "Victor Babeș" University of Medicine and Pharmacy, Revolutiei Ave. 1989, No. 9, 300041, Timişoara, Romania.
Odontology. 2023 Apr;111(2):360-374. doi: 10.1007/s10266-022-00741-5. Epub 2022 Sep 12.
In the present study are depicted valuable observations for practitioners, obtained from an in vitro study which aims to evaluate the compressive strength of occlusal veneers fabricated from 3 type of restorative materials, before and after 1 month of acidic artificial saliva exposure (pH = 2.939). In this context, 90 extracted human molars were prepared to receive computer-aided design/computer-aided manufacturing (CAD/CAM) occlusal veneers. The restorative materials considered in this study were: Cerasmart; Straumann Nice and Tetric CAD. The occlusal veneers were designed, milled and cemented with an adhesive dual-cure resin cement. From all the extracted human molars, only sixty specimens were immersed in acidic artificial saliva, for 1 month, at 37 °C ± 1 °C and part of this specimens were also thermo-cycled, between 5 and 55 °C ± 2 °C, before compressive strength test. The results showed a lower compressive strength for both the samples exposed to acidic artificial saliva as well as for the samples exposed to acidic artificial saliva and thermo-cycled. Scanning electron microscopy (SEM) showed that after compressive strength, all the specimens non-exposed to acidic artificial saliva, present extensive cracks formation at the surface of the restorations, and after exposure to acidic artificial saliva for 1 month, the surface damage was characterized by longitudinal and profound fractures of the restoration, as well as the fracture of the tooth structure. Between CAD/CAM materials tested, nanoceramic resin shows more favorable fracture patterns, both before and after acidic artificial saliva exposure.
本研究从一项体外研究中获得了对临床医生有价值的观察结果，该研究旨在评估在经历 1 个月的酸性人工唾液（pH = 2.939）暴露前后，由 3 种修复材料制成的牙合面贴面的抗压强度。在这种情况下，准备了 90 个人类离体磨牙来接受计算机辅助设计/计算机辅助制造（CAD/CAM）牙合面贴面。本研究中考虑的修复材料为：Cerasmart；Straumann Nice 和 Tetric CAD。牙合面贴面用一种具有双重固化性能的树脂水门汀进行设计、研磨和黏合。从所有提取的人类磨牙中，只有 60 个样本被浸入酸性人工唾液中，在 37°C±1°C 下放置 1 个月，其中一部分样本还进行了热循环，在 5 到 55°C±2°C 之间进行热循环，然后进行抗压强度测试。结果表明，暴露于酸性人工唾液的两组样本以及同时暴露于酸性人工唾液和热循环的样本的抗压强度均较低。扫描电子显微镜（SEM）显示，在进行抗压强度测试后，所有未暴露于酸性人工唾液的样本的修复体表面都出现了广泛的裂纹形成，而在暴露于酸性人工唾液 1 个月后，表面损伤的特征是修复体的纵向和深度裂缝以及牙体结构的断裂。在所测试的 CAD/CAM 材料中，纳米陶瓷树脂在暴露于酸性人工唾液前后都表现出更有利的断裂模式。
