超声冲洗对感染根管内毒素的灭活及清除作用

目的探讨超声冲洗对感染根管内毒素的灭活及清除作用。方法选择因严重慢性根尖周炎拔除的具有双根管的离体上颌前磨牙10颗，常规开髓，用改良双敞法预备根管，将3％过氧化氢溶液30 μL注入根管，行超声振荡，每根管振荡2 min，分别于根管预备后和超声振荡后取样，测量内毒素活性。另外在临床患者中选择患有慢性根尖周炎的双根管上颌前磨牙10颗，采用相同的方法进行根管预备，预备后以无菌蒸馏水为介质进行超声冲洗，每根管均冲洗2 min，分别于根管预备前、根管预备后和超声冲洗2 min后根管取样，测量内毒素活性。内毒素活性的测定采用动态浊度法鲎试验，并对超声处理前后根管内毒素活性的差异进行分析。结果离体牙超声振荡前，根管内毒素的活性平均为4.069 EU·mL-1，超声振荡后为16.410 EU·mL-1，二者差异有统计学意义（P<0.01），超声振荡后内毒素活性明显升高。临床样本中，根管预备前、根管预备后和超声冲洗后根管内毒素的平均活性分别为44.860、4.099、0.116 EU·mL-1，根管预备前与根管预备后内毒素活性的差异有统计学意义（P<0.01），根管预备后内毒素活性明显下降；根管预备后与超声冲洗后内毒素活性的差异也有统计学意义（P<0.01），超声冲洗后内毒素活性明显下降。结论在模拟临床操作的条件下，采用口腔科超声根管治疗仪进行超声冲洗可以明显增强根管冲洗液清除感染根管内毒素的作用，但不能增强根管冲洗液灭活感染根管内毒素的作用。

Study on the effect of ultrasonic irrigation in deactivating and eliminating the endotoxin in the root canals of chronic periapical periodontitis

Objective To study the effect of ultrasonic irrigation in deactivating and eliminating the endotoxin in the root canals of chronic periapical periodontitis. Methods 10 maxillary premolars with 2 root canals extracted because of serious chronic periapical periodontitis were opened conventionally and prepared with modified double-flared technique with apical foramen sealed. 30 μL 3% H_2O_2 solution was introduced into each root canal and 2 minutes ultrasonic vibration was given. Samples were taken before and after ultrasonic vibration. 10 maxillary premolars with 2 root canals of chronic periapical periodontitis of 10 patients in clinic were selected. The root canals of them were instrumented as above, followed by 2 minutes ultrasonic irrigation with asepsis distilled water. Samples were taken before, after root canal preparation and after ultrasonic irrigation. The endotoxin activity of them was tested by kinetic turbidimetric limulus test. Results The mean endotoxin activity of extracted premolars before ultrasonic vibration was 4.069 EU·mL~(-1) while after ultrasonic vibration it was 16.410 EU·mL~(-1). There was great statistical difference between them (P<0.01). The endotoxin activity after ultrasonic vibration was significantly higher than that of before vibration. The clinically mean endotoxin activity before, after root canal preparation and after ultrasonic irrigation were 44.860, 4.099, and 0.116 EU·mL~(-1) respectively. There was great statistical difference between the endotoxin activity before and after root canal preparation (P<0.01). After the preparation, the endotoxin activity droped obviously. There was great statistical difference between the endotoxin activity before and after ultrasonic irrigation (P<0.01). After ultrasonic irrigation, the endotoxin activity droped obviously. Conclusion Under the condition of simulating clinical work presence, the ultrasonic irrigation can not intensify the effect of the root canal rinse solution in deactivating the endotoxin of infected root canals, but it may intensify the effect of the root canal rinse solution in eliminating the endotoxin of infected root canals.