两种方法比较3种根管封闭剂体外抗菌效果的研究

Comparasion of the antibacterial efficacy of 3 root canal sealers in vitro

目的:比较3种根管封闭剂的抗菌效果。方法:直接接触(DCT)实验:将封闭剂AH-plus(A)、Gutta Flow(B)、iRoot SP(C)分别放入离心管中,分别于20 min和1、7、14、21 d取出,与粪肠球菌混合1 h后,进行细菌计数。感染根管模型(IRCM)实验:将成功建立感染根管内粪肠球菌模型的100个离体单根管人牙,随机分为A、B、C 3个实验组和1个阳性对照组(n=25)。根管预备充填后,将所有样本置于厌氧环境中分别培养20 min和1、7、14、21 d,每组于各时间点分别随机取出5个样本,收集充填材料和牙本质粉末进行细菌培养计数,并分别检测3种封闭剂的pH值。结果:在DCT中,A、C组与对照组相比,除20 min和1 d时能有效杀灭细菌(P<0.05)外,其他时间点均无统计学差异(P>0.05);A、C组比较P>0.05;B组在各时间点均抗菌效果差(P>0.05)。在IRCM实验中,A、C组抗菌效果的时间较DCT延长,与对照组相比C组除了在21 d抗菌性较差外,在其他各时间点均有较强的抗菌性(P<0.05);A组在20 min和1、7 d时均有较强的抗菌性(P<0.05);而B组在各时间点抗菌效果均较差(P>0.05)。C组在各时间点p H值最高(P<0.05),A、B组pH值比较,P>0.05。结论:pH的高低与封闭剂的抗菌性无直接对应关系。AH-plus和iRoot SP抗菌效果优于Gutta Flow。

AIM：To compare the antimicrobial effect of AH-plus（A）,GuttaFlow（B）and iRootSP（C）in vitro.METHODS：Direct contact test （DCT）and infected root canal model （IRCM）test were performed.In DCT, the sealers were respectively stored in the centrifuge tubes freshly mixed for 20 min,1,7,14 and 21 d.At each time point,Enterococcus faecalis bacterial suspension was exposed to the sealers for 60 m.The CFU of the bacteria were counted.In infected root canal model（IRCM）test,the root canals of 100 single rooted human teeth were infected with Enterococcus faecalis and were filled with AH-plus,GuttaFlow,and iRoot SP respectively （n=25 ）.25 non-filled root canals served as the controls.The filling materials and dentine powder were collected and cultured.The numbers of＆amp;nbsp;bacteria after filling were counted.Data were analyzed by one-way ANOVA.The pH values on sealers at different time points were also measured.RESULTS：In DCT,AH-plus and iRoot SP reduced CFUs at 20 min and 1 d （P〈0.05）,but the difference at other time points showed no statistical significance （P〉0.05）.GuttFlow showed no antibacterial efficacy at each time point （P＆gt;0.05）.In IRCMtest,AH-plus killed more bacteria than the control at 20 min,1 d and 7 d （P 〈0.05 ）.iRoot SP killed more bacteria than control at 20 min,1 d,7 d and 14 d （P〈0.05）.GuttFlow show no antibacterial efficacy at each time point （P＆gt;0.05）.In pH test,iRootsp had the high-est pH value at different times （11.04-11.78）.AH-plus had the similar pH value with GuttFlow.CONCLUSION：The pH value of the sealers can not explain their antibacterial effect.AH-plus and iRoot SP has antibacterial efficacy in virto.GuttaFlow is ineffective against Enterococcus faecalis.