五种冲洗液对根管内粪肠球菌抗菌效果的体外实验

Antimicrobial efficacy of five endodontic irrigants using an in vitro model infected by enterococcus faecalis

目的评价五种冲洗液对根管内粪肠球菌的杀菌效果。方法建立粪肠球菌根管内感染模型,将40个感染根管标本随机分为5组,每组8颗牙。器械预备时分别采用5.25%NaClO(A组)、2.5%NaClO(B组)、1%NaClO(C组)、17%EDTA(D组)、17%EDTA+1%NaClO(E组)冲洗根管。冲洗前、冲洗后即刻及冲洗后72h分别取样,37℃下CO2孵育箱中培养,48h后计数菌落数(CFU/ml)。结果冲洗后5组根管内的粪肠球菌量均显著下降(P<0.05),其中A组与其余各组间差异均有显著性(P<0.01);B组与C组、D组间差异有显著性(P<0.05),与E组间差异无显著性(P>0.05);C组与D组、E组间差异有显著性(P<0.05);D组与E组间差异有显著性(P<0.05)。根管冲洗后培养72h均有细菌生长。结论5.25%NaClO抗菌效果最强;17%EDTA+1%NaClO的抗菌效果优于1%NaClO,与2.5%NaClO抗菌效果相近似。

Objective To evaluate the antibacterial efficacy of five endodontic irrigants using an in vitro model infected by enterococcus faecalis （ E.faecalis ）. Methods The root canals of forty extracted teeth were infected by E. faecalis in vitro. The forty infected teeth were randomly and equally divided into five groups. All root canals were prepared, which underwent different root canal irrigation. NaC10 （5.25%） as irrigation was used for group A, while 2.5% NaC10 was used for group B, 1% NaCIO for group C, 17% EDTA for group D and 17% EDTA ＋ 1% NaCIO for group E. Microbiological samples were collected from root canal at three time points （before irrigation, immediately after irrigation and 72 hours after irrigation）, and were incubated at 37℃ and plated onto BHI age. The CFU was counted and analyzed. Results The number of E. faecalis in root canal in each of the five groups was effectively reduced （ P 〈0.05）. Group A was significantly more effective than other groups （ P 〈0.01 ）, while Group B was significantly more effective than group C and group D （ P 〈0.05）. Group C was significantly more effective than group D （ P 〈0.05）. Group E was significantly more effective than group C and group D （ P 〈0.05）. There was no significant difference between group B and group E （ P 〉 0.05 ）. Bacterial survival was observed in all canal of each group after a 3 - day - incubation. Conclusion The antibacterial efficacy of 5.25% NaCIO was best. The antibacterial efficacy of 17% EDTA ＋ 1% NaC10 was superior to 1% NaC10 and similar to 2.5% NaCIO.