超声波预备根管与Nd:YAG激光照射后根管牙本质的SEM研究

SEM evaluation of canal wall dentin following ultrasonic technique and Nd:YAG laser irradiation

目的：评价超声预备根管及Ｎｄ：ＹＡＧ 激光照射根管壁后，根管内壁的清洁度和管壁牙本质微结构的变化。方法：１２ 个离体成人上前牙分为４ 组制备根管：手用器械、超声根管治疗仪、手用器械＋ Ｎｄ：ＹＡＧ 激光照射、超声波＋ Ｎｄ：ＹＡＧ 激光照射，扫描电镜下观察并照像记录。结果：手用扩锉预备的根管内壁有涂层污染和病理组织残留；超声波预备后根管内壁清洁、涂层消除，牙本质小管口开放；手用器械或超声制备后辅以适当能量激光照射的管内壁牙本质小管口封闭，管间牙本质熔融，并形成空泡状结晶。结论：超声波预备根管可达到理想的清洁效果，但牙本质小管口开放易造成根管术后渗漏。而Ｎｄ：ＹＡＧ 激光照射有利于封闭牙本质小管口，减少根尖孔渗漏，还具有封闭根管内壁死腔的作用。

Aim:To evaluate the effectiveness of ultrasonic technique and Nd:YAG laser irradiation for cleaning and modifing the dentin surfaces of root canals. Methods: 12 extracted human upper anterior teeth were divided into four groups: hand instrumentation, ultrasonic techniqae, ultrasonic and Nd:YAG laser irradiation, hand instrumentation and Nd:YAG laser. After preparation, the inner sides of root canal were examined by SEM. Results: There were smear layer and debris remained in hand instrumented group. Ultrasonic preparation led an improvement in cleanness, without smear layer but leaving tubules open. The effect of Nd:YAG laser beam was melting and recrystallization of canal wall dentin. Conclusions: Ultrasonic preparation is an ideal techniqe for root canal cleaning while application of Nd:YAG laser will do good to reduce permeability and microleakage of canal wall dentin and seal lateral cavities in canals.