3种根管冲洗液对根管内可疑致病菌的抑制作用分析

目的对慢性根尖周炎患牙根管治疗过程中采用3种不同根管冲洗液进行根管预备,分析治疗前后根管内4种可疑致病菌的检出情况,了解不同冲洗液对这些可疑致病菌的抑制作用,为根管预备时冲洗液的选择和应用提供微生物学依据。方法选取60颗慢性根尖周炎患牙(单根管),根据根管预备时采用不同冲洗液随机分为3组(每组20颗):Na Cl O组(根管冲洗液为2.5%次氯酸钠,sodium hypochlorite); H2O2组(根管冲洗液为3%双氧水,hydrogen peroxide); PVP-I组(根管冲洗液为1%聚维酮碘,Povidone iodine,怡速欣)。分析根管治疗前后临床指数(clinical periapical index,CPI);同时采集根管预备前后患牙根管内感染物,提取细菌基因组DNA,合成针对粪肠球菌(Enterococcus faecalis,E.f)、具核梭杆菌(Fusobacterium nucleatum,F.n)、牙龈卟啉单胞菌(Porphyromonas gingivalis,P. g)和牙髓卟啉单胞菌(Porphyromonas endodontalis,P. e)的16S r DNA基因的特异性引物,运用实时荧光定量PCR(qRT-PCR)技术,比较分析E.f、F.n、P.g及P.e的检出率和检出量。结果 3组治疗前、后E.f、F.n、P.g和P.e的检出率相同,但可疑致病菌的检出量均有下降。其中3组间比较E.f、F.n和P.g检出量的下降率经统计学检验有差异(P<0.05),而P.e检出数量下降无显著差异(P>0.05); 2组间比较发现Na Cl O组和PVP-I组间E.f、F.n和P.g检出量的下降率统计学检验无差异(P>0.05); Na Cl O组和PVP-I组分别与H2O2组比较,E.f、F.n和P.g检出量的下降率大,差异有统计学意义(P<0.05)。PVP-I组P.e检出量的下降率大于H2O2组,差异有统计学意义(P<0.05)。结论使用3种不同根管冲洗液进行根管预备,能明显地减少感染根管内的E.f、F.n、P.g和P.e的量;与3%双氧水比较,用2.5%NaClO和1%PVP-I根管冲洗液对E.f、P.g和F.n抑制作用更明显;用1%PVP-I对P.e的抑制作用更明显。

Analysis of inhibitory effects of three endodontic irrigations on the pathogens in root canals

Objective To use three different endodontic irrigations for root canal preparation during chronic periodontitis treatment,then analyze the detection of four kinds of suspected pathogens before and after operation,and compare the inhibitory effects of three endodontic irrigating reagents(2.5% NaO Cl,3%H2O2,1%PVP-I)on four kinds of bacteria(E.f,F.n,P.g,P.e),to provide biological basis for the selection and application of irrigation in root canal preparation. Methods 60 single root teeth with chronic apical periodontitis were randomly divided into three groups. The first group(n = 20)was irrigated with 2.5% NaO Cl. The second group(n =20)was irrigated with 3% H2O2. The third group(n = 20)was irrigated with 1% PVP-I. Clinical periapical indexes were presented by the diameter of image shadows. Meanwhile the infectious agents before and after root canal preparation were collected,DNA of bacterial genome was extracted,specific primers against 16 S rD NA genes of E.f,F.n,P.g and P.e were compounded. Real-time quantitativepolymerase chain reaction(qRT-PCR)was used to compare the positive rates and quantities of four bacteria(E.f,F.n,P.g and P.e)in different groups. Statistical analysis was performed using the Mann-Whitney test. Results The positive rates of E.f,F.n,P.g and P.e were the same in three groups before and after treatment,but the positive rates of suspected pathogens decreased. There was no significant difference in the decrease of the positive rates of P.e in three groups(P>0.05),whereas there was difference in E.f,F.n and P.g(P<0.05). The numbers of E.f,F.n and P.g were reduced significantly in both NaC lO-group and the(PVP-I)-group compared to the H2O2-group(P<0.05). The detection rate of P.e in the(PVP-I)-group was significantly lower than that in the H2O2-group(P<0.05).Conclusions 2.5% NaC lO,1% PVP-I and 3% H2O2 can effectively inhibit the growth of E. f, F. n, P. g and P. e in infectious root canals. 2.5% NaC lO and 1% PVP-I have no significant inhibitory effect on these four bacteria,but both show inhibitory effects on E. f,F. n and P. g compared to 3% H2O2.1% PVP-I shows better inhibitory effect on P.e than 3% H2O2.