Comparison of two rotary systems in bacteria/lps removal from endodontic infections: randomized clinical trial

Abstract: This clinical study compared the effectiveness of two rotary systems: HyFlex CM (Coltene-Whaledent, Altstetten, Switzerland) and ProTaper Next (Dentsply Sirona, Ballaigues, Switzerland) on the removal of cultivable bacteria and endotoxins from primarily infected root canals. This study was designed as a randomized single-blinded, 2-arm, clinical trial. Twenty-four primarily infected root canals were selected and randomly divided into 2 groups: HyFlex CM (n = 12); and ProTaper Next (n = 12). Samples were collected before and after the biomechanical preparation and inoculated in specific flasks. Irrigation was performed using 2.5% sodium hypochlorite. A kinetic turbidimetric lysate assay of limulus amoebocytes was used to quantify endotoxins. Microbiological culture technique was used to determine the count of bacterial colony forming units (CFU/mL). Data collected were statistically analyzed using SigmaPlot 12.0 for Windows. The Two-Way ANOVA statistical test was performed and the level of significance was 5%. In the samples before the biomechanical preparation, cultivable bacteria and endotoxins were evidenced in 100% of the cases. The culture analysis revealed that there was no statistically significant difference in the bacterial reduction between the two instrumentation systems. Endotoxins were present in 100% of the canals after instrumentation and there was no statistical difference between the two systems in endotoxin reduction. Thus, it was concluded that both instrumentation systems were effective in reducing root canal bacteria and endotoxins with primary endodontic infection and that there was no statistical difference between them. However, no system was able to eliminate 100% of the bacteria and their by-products.

摘要：本临床研究对比了两种旋转器械系统——HyFlex CM（瑞士阿尔施泰滕市Coltene-Whaledent公司）与ProTaper Next（瑞士巴莱格市登士柏西诺德公司）——从原发感染根管中清除可培养细菌及内毒素的效果。本研究为随机单盲双臂临床试验，共纳入24颗原发感染根管，随机分为两组：HyFlex CM组（n=12）与ProTaper Next组（n=12）。分别在根管预备前后采集样本，并接种于专用培养瓶中。根管冲洗采用2.5%次氯酸钠溶液。采用鲎变形细胞溶解物动态比浊测定法对内毒素进行定量检测，采用微生物培养技术检测细菌菌落形成单位（CFU/mL）计数。采用Windows版SigmaPlot 12.0对采集的数据进行统计学分析，检验方法为双向方差分析（Two-Way ANOVA），检验水准设定为5%。根管预备前的所有样本中，可培养细菌与内毒素的检出率均为100%。培养分析结果显示，两种器械系统的细菌清除率无统计学差异。器械预备后，所有根管样本仍可检出内毒素，且两种系统的内毒素清除率亦无统计学差异。综上，两种器械系统均能有效清除原发牙髓感染根管内的细菌与内毒素，且二者效果无统计学差异，但两种系统均无法完全清除所有细菌及其代谢产物。