不同功率Diode激光用于乳牙根管清洁的体外研究

目的: 评价不同功率Diode激光(810 nm)对乳牙根管壁玷污层的清除效果。方法: 选取66颗因滞留拔除的乳前牙,随机分为:阴性对照组(未处理,n=6)、阳性对照组(5.25%次氯酸钠冲洗, n=6)和实验组(Diode激光照射,n=54);实验组按不同激光功率分为0.1 W、0.5 W、1.0 W、1.5 W、2.0 W、2.5 W、3.0 W、3.5 W和4.0 W组(n=6)。将光纤头插入根管至工作长度后照射,扫描电子显微镜(SEM)观察根管内壁清洁效果。结果: SEM下可见根管上段、中段和下段分别在1.0W、1.5W和2.0W时有明显的清洁效果,优于与之相邻低功率组和阳性对照组(P<0.05),与高于此功率组相比无显著差异;功率在3.0 W时,根管管壁开始出现牙本质熔融。结论: Diode激光可有效清除乳牙根管玷污层,其有效功率范围为1.0~2.5 W,最佳功率为2.0 W。

Cleaning Effect of Diode Laser on Smear Layer in Root Canals of Primary Teeth.

Objective: To evaluate the efficiency on smear layer removal of primary teeth after irradiating with 810-nm Diode laser energy at different parameters. Methods: Sixty-six human anterior teeth with apical foramen extracted for retained primary teeth were selected. Samples were randomly divided into negative control group (n=6), positive control group (5.25% sodium hypochlorite, n=6) and experimental groups (Diode Laser, n=54). The experimental groups were divided into 6 subgroups due to different power protocols, including 0.1W, 0.5W, 1.0W, 1.5W, 2.0W, 2.5W, 3.0W, 3.5W and 4.0W. Teeth were subjected to scanning electron microscope (SEM) and the remaining smear layer was evaluated. Results: Diode laser at 1.0W, 1.5W and 2.0W removed the smear layer more effectively at the coronal, middle and apical thirds of root canals respectively, which demonstrated statistically significant differences compared to the lower power groups or the positive group (P<0.05), while these groups showed no significant differences compared to the high power groups. When the power was at 3.0W or more than 3.0W, a few parts of the dentin surface began to fuse. Conclusion: Diode Laser at 1.0-2.5W has a positive effect on removing smear layer of primary teeth and 2.0W is more appropriate.