模拟咀嚼条件下层状陶瓷的损伤图谱
Damage maps for layered ceramics under simulated mastication.
作者信息
Kim J-H, Kim J-W, Myoung S-W, Pines M, Zhang Y
机构信息
Department of Biomaterials and Biomimetics, New York University College of Dentistry, New York, NY, USA.
出版信息
J Dent Res. 2008 Jul;87(7):671-5. doi: 10.1177/154405910808700706.
Ceramic restorations, whether monolithic (single layer) or porcelain-veneered, often chip and fracture from repeated occlusal loading. Occlusion involves the opposing tooth sliding along the cuspal incline surface with an applied biting force (off-axis loading). We hypothesized that off-axis contact-load-slide-liftoff fatigue, as compared with normal axial fatigue loading, produces different fracture modes and fatigue lifespans of layered ceramics. Monolithic glass plates were epoxy-bonded to polycarbonate substrates as a transparent model for an all-ceramic crown on dentin. Off-axis and axial (control) cyclic loading was applied through a hard sphere in water, with a mouth-motion machine. The off-axis loading is more deleterious for contact-induced occlusal surface fracture, but less harmful for flexure-induced cementation surface fracture of brittle layers than the axial loading. This is because of the tangential load component associated with the off-axis loading. Clinical relevance is discussed.
陶瓷修复体，无论是整体式（单层）还是烤瓷贴面式，常常会因反复的咬合负荷而出现崩瓷和断裂。咬合涉及相对的牙齿在施加的咬合力（非轴向负荷）作用下沿着牙尖斜面滑动。我们推测，与正常的轴向疲劳负荷相比，非轴向接触 - 负荷 - 滑动 - 抬起疲劳会产生不同的断裂模式和层状陶瓷的疲劳寿命。将单片玻璃板用环氧树脂粘结到聚碳酸酯基板上，作为牙本质上全瓷冠的透明模型。通过置于水中的硬球，利用口腔运动模拟器施加非轴向和轴向（对照）循环负荷。与轴向负荷相比，非轴向负荷对接触引起的咬合面断裂更具损害性，但对脆性层的弯曲引起的粘结面断裂危害较小。这是由于与非轴向负荷相关的切向负荷分量所致。文中讨论了其临床相关性。
Zotero 插件