深龋乳牙根管细菌学分析

目的本研究的目的是对患有深龋的乳牙根管内细菌进行分析。方法选择12颗深龋乳牙，其中3颗有冷热刺激痛，其余9颗无临床症状。分别在微需氧(80％N2，10％H2，10％CO2)及厌氧条件(90％N2，10％CQ)下进行患牙根管细菌分离和鉴定。结果结果显示有症状牙的菌落形成单位(Colony Fomation Unit，简称CFU，下同)比无症状牙高，但二者间的差异无显著性。在这两组中，根管细菌的组成相似，并且与深龋的细菌组成相似。变链菌和乳杆菌占可培养细菌的比例比其它细菌高，差异有显著性，而且变链菌和乳杆菌的检出率比其它细菌高，差异亦有显著性。专性厌氧菌，如消化链球菌、韦荣氏菌、梭杆菌和普氏菌也有所检出，但其检出率和占可培养菌百分比均很低。结论微需氧致龋菌是乳牙龋源性牙髓炎的主要致病菌。

Microbial flora of root canal of human deciduous teeth with deep caries

Objective To investigate the bacteria l composition of infected root canal of human deciduous teeth with deep caries.Methods Twelve deciduous teeth with deep caries not expos ing the pulp chamber were selected for the study.Three teeth were complained by patients being sensitive to cold or heat recently,while the others had no sympto ms.The bacteria of the pulp were isolated and identified in 80%N 2,10%H 2,10%C O 2 and in 90%N 2,10%CO 2,respectively. Results The CFU of the symptomatic teeth was higher than that of the symptomless teeth,but the difference was not significant.In the two groups,the bacterial composition of pulp was similar,and similar to the composit ion of deep caries.The percent of S.mutans and Lactobacillus to the total cultiv ated bacteria were much higher than the other bacteria,and the frequency of S.mu tans and Lactobacillus were much higher than the other bacteria.Obligate anaerob es such as Peptostreptococcus,veillonella,Fusobaceterium and Prevotellas were is olated,but the frequency and the percent to the total cultivated bacteria were v ery low.Conclusion We inferred that the infection of the pulp in deciduous teeth caused by caries was mainly caused by cariogenic microaerophilou s bacteria.