摘要目的 评价5种终末冲洗液在模拟的粪肠球菌感染根管中抗菌性及残余抗菌性,以期寻找最佳的根管治疗终末冲洗液.方法 在100颗无龋单根前牙根管内建立标准的粪肠球菌感染模型,并采用随机数字表法随机抽取其中30颗检测细菌模型建立的质量.用机动ProTaper以Crown-Down法对剩余70颗实验牙进行根管预备,将70颗实验牙分为7组,每组10颗,分别用A(Qmix,成分为双胍类抗菌剂、钙离子螯合剂和表面活性剂)、B(MTAD,成分为多西环素、柠檬酸和Tween 80)、C(0.2％西曲溴铵,cetrimide,CTR)、D(2％氯己定,chlorhexidine,CHX)及E(17％乙二胺四乙酸,ethylene diamine tetraacetic acid,EDTA)5种冲洗液对5组预备后的实验牙行终末冲洗;其余2组1组用蒸馏水冲洗(蒸馏水组),另1组不进行终末冲洗(未冲洗组).将终末冲洗后的5个实验组及2个对照组分别于冲洗后的第0至14天每天进行取样、细菌培养、观察、记录,检测根管的根冠1/3、根中1/3及根尖1/3冲洗液的抗菌性及残余抗菌性,将脑心浸液出现浑浊计为有菌生长.采用皮尔逊卡方检验行抗菌性的统计学分析,采用重复测量资料的广义估计方程法行不同组间残余抗菌性分析.结果 抗菌性:终末冲洗后第0天,A、B、C、D组的根冠1/3、根中1/3及根尖1/3均无细菌生长;B组和蒸馏水组根冠1/3、根中1/3及根尖1/3无细菌生长的样本均分别为7、6、9个,A、B、C、D组与E组、蒸馏水组和未冲洗组差异均有统计学意义(P＜0.05).残余抗菌性:终末冲洗后的第1、2、3天,E组、蒸馏水组、未冲洗组分别与A、B、C、D组两两比较差异均有统计学意义(P＜0.05),其余各组间两两比较差异均无统计学意义(P＞0.05);终末冲洗后第4～11天,A组到第6天、B组到第9天、C组到第8天、D组到第5天仍有部分标本无细菌生长;但上述4组间两两比较差异均无统计学意义(P＞0.05).根冠1/3与根尖1/3、根中1/3与根尖1/3的抗菌性差异均有统计学意义(P＜0.05),根冠1/3与根中1/3的抗菌性差异无统计学意义(P＞0.05).结论 冲洗液A、B、C、D均有一定的抗菌性,冲洗液E和蒸馏水无抗菌作用;根冠1/3冲洗液的抗菌性优于根尖1/3;冲洗液A、B、C、D均有一定的残余抗菌性,残余抗菌性的持续时间由长到短依次为:B、C、A、D.

abstractsObjective To evaluate antibacterial and residual antimicrobial activities of five root canal irrigants including Qmix,MTAD(mixture of a tetracycline isomer,an acid,and a detergent),0.2％ cetrimide(CTR),2％chlorhexidine(CHX) and 17％ethylene diaminetetraacetic acid(EDTA) and to find the most optimal final irrigants for using in root canal therapy.Methods The standard enterococcus infection models were built up in 100 single rooted incisors with single canal.Totally 30 teeth were selected by using random number tablefor detecting the quality of the bacteria model.Crown-down technique with rotary ProTaper system was used to prepare the root canals.Then the teeth were randomly divided into seven groups of which five groups were irrigated with five different irrigants respectively,one group was irrigated with distilled water(distilled water group) and one group was no-irrigation group.Each tooth was sectioned into three parts:apical 1/3,middle 1/3 and coronal 1/3.After irrigation,specimenswere cultivated from day 0 to day 14.All statistical analyses were performed by means of SPSS 17.0 software.Chi-squared test was used to evaluate antibacterial activities.Generalized estimating equations was used to evaluate residual antimicrobial activities.Results All samples rinsed with Qmix,MTAD,CTR,CHX were bacteria-free in 0 day.The samples rinsed with EDTA and distilled water had no bacteria in 7 coronal sections,6 middle sections and 9 apical sections,respectively.The results of Qmix,MTAD,CTR and CHX groups showed significant difference when compared with that of distilled water,EDTA and control groups(P＜0.05).Residual antimicrobial resultsin EDTA,distilled water,no-irrigation groups showed significant differences compared with that of Qmix,MTAD,CTR,CHX groups according to pairwise comparison(P＜O.05) on day 1,2 and 3.There was no significant difference between the other two groups(P＞0.05).Antimicrobial properties on the coronal 1/3 and apical 1/3,middle 1/3 and apical 1/3 showed significant difference(P＜0.05) while middle 1/3 and coronal 1/3 showed no significant difference(P＞0.05).Conclusions Qmix,MTAD,CTR and CHX had an antimicrobial activity,but could not destroy Enterococcus faecalis completely.Antimicrobial activity in coronal 1/3 was better than in apical 1/3.Qmix,MTAD,CTR and CHX had a residual antimicrobial activity with various lasting times.The lasting time of residual antimicrobial activity was as follow:MTAD＞ CTR＞Qmix＞CHX.EDTA had no antibacterial and residual antimicrobial activities.