根管治疗术和全部去髓术是保存牙齿的重要治疗方法。进行根管治疗术和全部去髓术时,必须准确测量牙齿根管的长度。目前国内测量根管长度的方法有两种:一是主观感觉法,操作者根据自己的经验用扩孔器械探测根尖孔的位置,或者根据患者是否有疼痛感觉来判断器械是否超出根尖孔,利用这种操作者或患者的主观感觉来测量根管长度。这种方法显然是经验性的,不科学的。 Root canal therapy and all to the pulp surgery is an important treatment for the preservation of teeth. Root canal therapy and all to the pulp surgery, you must accurately measure the length of the root canal. Currently there are two ways to measure the length of the root canal: First, the subjective sensory method, the operator according to their own experience with the reaming device to detect the position of the apical foramen, or according to whether the patient has a pain feeling to determine whether the device exceeds the apical foramen , Using this subjective perception of the operator or patient to measure the root canal length. This method is obviously empirical and unscientific.