3种连续旋转镍钛系统对感染根管内粪肠球菌清除效果的比较

Comparison of three rotary file systems for removal of Enterococcus faecalis from infected root canals

目的比较新型连续旋转镍钛系统EZ Pass与两种传统的连续旋转镍钛系统(ProTaper Gold及ProTaper Next)对体外构建的上颌中切牙感染根管内粪肠球菌的清除效果。方法选取因牙周病或正畸新鲜拔除的单根上颌中切牙51颗,建立根管内粪肠球菌感染模型。取1个感染样本进行脱矿、包埋、切片、Talor改良的Brown&Brenn技术染色及光镜下观察;将剩余的50个感染样本随机分为5组:EZ Pass组、ProTaper Gold组、ProTaper Next组、0.9%NaCl组及2%NaClO组。在采用上述机械和化学手段清除根管内细菌前、后分别进行根管内取样,琼脂板菌落计数法定量检测各组根管内细菌减少率及对数减少值之间的差异。结果根管表面可见广泛的粪肠球菌生物膜,大量的细菌渗入牙本质小管深层,最大渗透深度约为475μm。EZ Pass组、ProTaper Gold组、ProTaper Next组和2%NaClO组根管内细菌减少率之间的差异无统计学意义(P>0.05),但均显著高于0.9%NaCl组(P<0.01)。EZ Pass组(1.47±0.12)、ProTaper Gold组(1.74±0.14)及ProTaper Next组(1.63±0.17)根管内细菌对数减少值的组间差异无统计学意义(P>0.05),但上述3组的对数减少值都高于2%NaClO组(P<0.05),后者显著高于0.9%NaCl组(P<0.01)。结论EZ Pass的根管内细菌清除能力与ProTaper Gold和ProTaper Next相当,值得临床推广应用。

Objective To compare the efficacy of a novel rotary file system(EZ Pass)with two well-established rotary file systems(ProTaper Gold and ProTaper Next)for removal of Enterococcus faecalis from infected root canals in extracted maxillary central incisors.Methods Models of root canal infection with Enterococcus faecalis were constructed in 51 extracted single rooted maxillary central incisors.One of the incisor model with infected root canal was demineralized,sectioned,and stained with Brown&Brenn technique for microscopic observation;The remaining 50 models were randomly divided into 5 groups(n=10)for treatment with EZ Pass,ProTaper Gold,ProTaper Next,0.9%NaCl or 2%NaOCl.Samples were collected from the infected root canals before and after the treatments to assess the percent reduction and logarithmic reduction value of CFU in the root canals.Results The incisors with root canal infection by Enterococcus faecalis showed obvious biofilms on the surface of the root canals and massive bacterial invasion deep into the dentinal tubules,with a maximum invasion depth of about 475μm.The percent reduction of the CFU did not differ significantly after treatments with EZ Pass,ProTaper Gold,ProTaper Next and 2%NaOCl(P>0.05),but all these treatments resulted in significantly greater reduction than 0.9%NaCl(P<0.01).The logarithmic reduction of CFU were comparable after treatments with EZ Pass(1.47±0.12),ProTaper Gold(1.74±0.14)and ProTaper Next(1.63±0.17;P>0.05).Conclusion EZ Pass can significantly reduce the bacterial load in infected root canals with an equivalent bacterial elimination capacity to ProTaper Gold and ProTaper Next.