Universidade de São Paulo, Departamento de Dentística, Faculdade de Odontologia, São Paulo, SP, Brazil.
J Biomed Opt. 2012 Nov;17(11):118002. doi: 10.1117/1.JBO.17.11.118002.
Endotoxins released in the dental root by Gram-negative microorganisms can be neutralized by calcium hydroxide, when this medication is applied inside the root canal for at least seven days. However, several clinical situations demand faster root canal decontamination. Thus, for faster endotoxin neutralization, endodontists are seeking additional treatments. The in vitro study tested whether or not intracanal Nd:YAG laser irradiation would be able to neutralize endotoxin within the human dental root canal in a single session. Twenty-four human teeth with one root were mounted between two chambers. After conventional endodontic treatment, root canals were contaminated with Escherichia coli endotoxin. Then they were irradiated or not (controls) in contact mode with an Nd:YAG laser (1.5 W, 15 Hz, 100 mJ and pulse fluency of 124 J/cm2). The endotoxin activity was measured using the limulus lysate technique and data were statistically compared (p≤0.05). The concentration of active endotoxin measured in the negative control group was significantly lower than that of the positive control group (p=0.04). The concentrations of endotoxin in both irradiated groups were significantly lower than that of the positive control group (p=0.027) and similar to that of negative control group (p=0.20). A single session of intracanal Nd:YAG laser irradiation is able to neutralize endotoxin in the dental root tissues.
由革兰氏阴性微生物在牙根中释放的内毒素可以被氢氧化钙中和，当这种药物在根管内至少应用七天时。然而，一些临床情况需要更快的根管去污。因此，为了更快地中和内毒素，牙髓病医生正在寻求其他治疗方法。这项体外研究测试了在单次根管内 Nd:YAG 激光照射是否能够在人类根管内中和内毒素。二十四颗具有一个牙根的人类牙齿被安装在两个腔室之间。在常规根管治疗后，用大肠杆菌内毒素污染根管。然后用接触模式用 Nd:YAG 激光（1.5 W，15 Hz，100 mJ 和脉冲通量 124 J/cm2）对其进行照射或不照射（对照）。使用鲎试剂技术测量内毒素活性，并对数据进行统计比较（p≤0.05）。阴性对照组中活性内毒素的浓度明显低于阳性对照组（p=0.04）。两个照射组的内毒素浓度均明显低于阳性对照组（p=0.027），与阴性对照组相似（p=0.20）。单次根管内 Nd:YAG 激光照射能够中和牙本质组织中的内毒素。
