Division of Restorative Sciences, University of Southern California, Herman Ostrow School of Dentistry of USC, Los Angeles, CA, USA.
J Prosthet Dent. 2011 Apr;105(4):217-26. doi: 10.1016/S0022-3913(11)60035-8.
Ultra-thin bonded posterior occlusal veneers represent a conservative alternative to traditional inlays and complete coverage crowns for the treatment of severe erosive lesions. There is a lack of data regarding selection of the most appropriate material and its influence on fatigue resistance, which may affect restoration longevity.
The purpose of this study was to assess the influence of CAD/CAM restorative material (ceramic vs. composite resin) on fatigue resistance of ultra-thin occlusal veneers.
A standardized nonretentive tooth preparation (simulating advanced occlusal erosion) was applied to 40 extracted molars including removal of occlusal enamel, and immediate dentin sealing (Optibond FL). All teeth were restored with a 0.6 mm-thick occlusal veneer (Cerec3 chairside CAD/CAM system). Reinforced ceramics (Empress CAD and e.max CAD) and composite resins (Paradigm MZ100 and XR (experimental blocks)) were used to mill the restorations (n=10). The intaglio surfaces were HF-etched and silanated (reinforced ceramics) or airborne-particle abraded and silanated (composite resins). Preparations were airborne-particle abraded and etched before restoration insertion. All restorations were adhesively luted with preheated Filtek Z100. Cyclic isometric loading was applied at 5 Hz, beginning with a load of 200N (x5,000), followed by stages of 400, 600, 800, 1000, 1200 and 1,400N at a maximum of 30,000 cycles each. The number of cycles at initial failure (first cracks) was recorded. Specimens were loaded until catastrophic failure (lost restoration fragment) or to a maximum of 185,000 cycles. Groups were compared using the life table survival analysis (α=.008, Bonferroni-method).
Empress CAD and e.max CAD initially failed at an average load of 500N and 800N, respectively with no specimen withstanding all 185,000 load cycles (survival 0%); with MZ100 and XR the survival rate was 60% and 100%, respectively.
Both composite resins (MZ100 and XR) increased the fatigue resistance of ultra-thin occlusal veneers (P<.001) when compared to the ceramics evaluated (Empress CAD and e.max CAD).
超薄粘结后牙贴面是治疗严重侵蚀性病变的传统嵌体和全冠覆盖的一种保守替代方法。对于最合适的材料的选择及其对疲劳强度的影响，缺乏相关数据，这可能会影响修复体的使用寿命。
本研究旨在评估 CAD/CAM 修复材料（陶瓷与复合树脂）对超薄牙合面贴面的疲劳强度的影响。
对 40 颗离体磨牙进行了非保留性牙体预备（模拟晚期牙合面侵蚀），包括去除牙合面釉质和即刻牙本质封闭（Optibond FL）。所有牙齿均用 0.6 毫米厚的牙合面贴面（Cerec3 椅旁 CAD/CAM 系统）修复。使用强化陶瓷（Empress CAD 和 e.max CAD）和复合树脂（Paradigm MZ100 和 XR（实验块））来加工修复体（n=10）。凹面进行 HF 酸蚀和硅烷化（强化陶瓷）或气固喷砂和硅烷化（复合树脂）。修复体插入前对预备体进行气固喷砂酸蚀。所有修复体均采用预热 Filtek Z100 进行胶粘固位。在 5 Hz 下进行等距循环加载，初始负载为 200N（x5,000），随后分别为 400、600、800、1000、1200 和 1,400N，每个阶段最大循环 30,000 次。记录初始失效（第一次出现裂纹）的循环次数。将试件加载至灾难性失效（丢失修复体碎片）或最大 185,000 次循环。使用寿命表生存分析（α=.008，Bonferroni 方法）比较各组。
Empress CAD 和 e.max CAD 的初始失效平均载荷分别为 500N 和 800N，没有试件能承受所有 185,000 次加载循环（生存率为 0%）；MZ100 和 XR 的生存率分别为 60%和 100%。
与评估的陶瓷材料（Empress CAD 和 e.max CAD）相比，两种复合树脂（MZ100 和 XR）均能提高超薄牙合面贴面的疲劳强度（P<.001）。
