KaVo KEY激光对感染根管和根面粪肠球菌杀菌效果的体外研究

目的评价KaVo KEY激光对感染根管和根面粪肠球菌的杀菌效果。方法选用50颗人离体单根牙,建立粪肠球菌感染模型,随机分为3组,即空白对照组、激光组1和激光组2。激光组1和激光组2分别使用80、140 mJ能量激光照射整个根面,照射后再分别照射根管15、30 s。标本处理前与处理后即刻取样进行细菌培养计数。分别取激光处理后根管标本3个不同深度（100、200、300 μm）的牙本质碎屑培养24 h,比浊计数。结果激光处理后根管内和根面各组的细菌量均显著下降（P<0.05）,但各组间灭菌效果差异无统计学意义（P>0.05）。各个深度的牙本质碎屑培养24 h比浊显示80 mJ能量激光照射可清除100 μm处牙本质小管内的细菌,且照射15 s时差异有统计学意义（P<0.05）,其余组与空白对照组比较差异无统计学意义。结论KaVo KEY激光能有效杀灭感染根管内壁和根面的粪肠球菌;用低能量、短时间照射根管可有效清除浅层牙本质小管内的粪肠球菌。

The antibacterial efficacy of KaVo KEY laser on Enterococcus faecalis within infected root canals and roots surface in vitro

Objective To evaluate the antibacterial efficacy of KaVo KEY laser on Enterococcus faecalis（E. faecalis） within infected root canals and roots surface in vitro. Methods Fifty single-rooted teeth were selected, and infected root canals and roots surface vitro models were prepared. Then, these specimens were divided into three groups. First group were untreated as blank control. The other two groups were the laser groups: Irradiated 15 s and 30 s respectively with 80 mJ and 140 mJ in root canals and on roots surface. Microbiological samples were collected from root canals and roots surface at two time points（before irrigation and immediately after irrigation）. The dentin chips from three different zone of part of root canals in each group were immediately collected and were cultured for 24 h in brain heart infusion（BHI）. Results The number of E. faecalis in root canal and root surface in each of the groups were effectively reduced（P <0.05）, and there was no significant difference between each two groups（P>0.05）. Compared with the blank control, the bacterial number in 100 μm of dental tubules decreased after specimens treated with 80 mJ, and the experimental group irradiated 15 s was a significant decease（P<0.05）. The other groups were no changed in different zone of dental tubules. Conclusion KaVo KEY laser is effective on sterilizing infected root canals and roots surface. It has also significant effect on bacterial in superficial dental tubules with low energy and short time.