Kondoh Yoshihiro, Takeda Tomotaka, Ozawa Takamitsu, Narimatsu Keishiro, Konno Michiyo, Fujii Toshiki, Sekiguchi Chieko, Nakajima Kazunori, Ishigami Keiichi, Shomura Masahito
Department of General Dentistry, Tokyo Dental College Chiba Hospital.
Department of Sports Dentistry, Tokyo Dental College.
Open Dent J. 2013 Nov 29;7:162-8. doi: 10.2174/1874210601307010162. eCollection 2013.
This pilot study compared impact strain at the core and root surfaces between two different post-core systems.
The form of a bovine mandibular front tooth was modified to resemble that of a human maxillary incisor as a test specimen. A cast post and core (Metal PC) and composite resin and glass fiber-reinforced epoxy resin post (Fiber-Resin PC) system were tested. Four gauges were affixed to the buccal and lingual surfaces of the core and root. The specimens were then embedded in a metal mold using dental stone. A pendulum-type device with a pyramid-shaped metal impact object with a titanium alloy head was used to provide 2 different shock forces. Maximum distortion was measured and analyzed.
Distortion at the core at each measurement point and total amount of distortion with Fiber-Resin PC was significantly greater (p<0.05) than that with Metal PC against both impact forces. On the other hand, distortion at the root at the buccal measurement point with Fiber-Resin PC was significantly less than that with Metal PC against both impact forces. Total distortion was significantly less with Fiber-Resin PC than that with Metal PC against the greater impact shock. Acceleration with Fiber-Resin PC was significantly less than that with Metal PC against both impact forces.
Fiber-Resin PC has the potential to protect remaining root against traumatic force. This suggests that a Fiber-Resin PC is more suitable for non-vital teeth against not only occlusal but also traumatic impact force.
本前瞻性研究比较了两种不同桩核系统在核部和牙根表面的冲击应变。
将牛下颌前牙的外形修改为类似人类上颌切牙作为测试样本。测试了铸造桩核（金属桩核）和复合树脂与玻璃纤维增强环氧树脂桩（纤维树脂桩核）系统。在核部和牙根的颊侧和舌侧表面粘贴四个应变片。然后使用牙科石膏将样本嵌入金属模具中。使用带有钛合金头部的金字塔形金属冲击物的摆锤式装置提供两种不同的冲击力。测量并分析最大变形。
在两种冲击力作用下，纤维树脂桩核在每个测量点处核部的变形以及总变形量均显著大于金属桩核（p<0.05）。另一方面，在两种冲击力作用下，纤维树脂桩核在颊侧测量点处牙根的变形显著小于金属桩核。在较大冲击力作用下，纤维树脂桩核的总变形显著小于金属桩核。在两种冲击力作用下，纤维树脂桩核的加速度显著小于金属桩核。
纤维树脂桩核有保护剩余牙根免受外力损伤的潜力。这表明纤维树脂桩核不仅更适合于无活力牙承受咬合冲击力，也适合承受外力冲击力。
