Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Osaka, Japan.
J Endod. 2013 Jan;39(1):88-91. doi: 10.1016/j.joen.2012.06.033. Epub 2012 Aug 9.
It is difficult to make a definite diagnosis of a cracked tooth solely based on an inspection within the root canal, especially in case of microcracks. At present, there seems to be no established method to detect dentinal microcracks in roots; therefore, the current detection techniques need to be improved. Vibrothermography (VibroIR) helps to detect microcracks by the friction heat generated from ultrasonic vibration. The purpose of this study was to establish a novel method using VibroIR to detect dentinal microcracks.
The root canals of 20 roots with cracks and control roots were prepared after removing the tooth crowns. A tapered indenter was inserted into the root canal and pressed until a microcrack was created under an optical microscope. Using VibroIR, the detection trials for dentinal microcracks were performed with an ultrasonic vibration power ranging from 0.43 to 1.48 W at an angle of 0°, 30°, 45°, 60°, and 90° between the ultrasonic vibration point and the microcrack line. After the detection test, the microcrack width was measured with an optical microscope.
Frictional heat was detected in the microcracks with thermography at 0.89 to 1.48 W and at an ultrasonic vibration point angle less than 60° from the crack line for 10 seconds. Microcracks with a width of 4 to 35.5 μm were detected with this method.
VibroIR may be an effective method for the diagnosis of root dentinal microcracks.
仅通过根管内检查很难对牙隐裂做出明确诊断，尤其是对于微裂纹。目前，似乎还没有一种确定的方法可以检测根内的牙本质微裂纹；因此，目前的检测技术需要改进。声热像法（VibroIR）通过超声振动产生的摩擦热来帮助检测微裂纹。本研究的目的是建立一种使用 VibroIR 检测牙本质微裂纹的新方法。
在去除牙冠后，对 20 个有裂纹的牙根和对照牙根进行根管制备。将锥形压头插入根管中，并按压直至在光学显微镜下形成微裂纹。使用 VibroIR，在 0°、30°、45°、60°和 90°的超声振动点与微裂纹线之间的角度下，用 0.43 至 1.48 W 的超声振动功率进行牙本质微裂纹的检测试验。检测试验后，用光学显微镜测量微裂纹的宽度。
在 0.89 至 1.48 W 的温度记录和超声振动点角度小于 60°的情况下，热像图中检测到微裂纹有摩擦热，持续 10 秒。该方法检测到宽度为 4 至 35.5 μm 的微裂纹。
VibroIR 可能是诊断牙根牙本质微裂纹的有效方法。
