儿童牙齿表面的菌群分布与龋齿的关系

本实验从幼儿园和小学一年级的学生中选择５－８岁的无龋齿和有龋齿的儿童各４５例，进行牙齿表面的菌群分布与龋齿关系的研究，结果在有龋组中分离到变形链球菌８株，放线菌６株及拟杆菌２６株，而在无龋组中未分离到变形链球菌，分离到放线菌１株，拟杆菌１４株，两组比较，以上三种菌有显著差异（Ｘ２检验Ｐ＜０．０５）。说明除变形链球菌是主要的致龋菌外〔１，２〕，还应考虑放线菌和拟杆菌在龋齿发生上的作用。此外，我们还发现两组的兼性厌氧菌的分布也有所不同，无龋组中分离到棒状杆菌２９株，而有龋组中分离到棒状杆菌１１株，小肠结肠炎耶尔森氏菌７株，两组也有明显差异，故我们认为龋齿发生的原因可能是多方面的，就病原菌来说，也可能是多种细菌的混合作用，从两组兼性厌氧菌与无芽胞厌氧菌的分布不同来看，亦应考虑龋齿的发生与口腔内生态平衡有关

STUDY ON THE RELATION BETWEEN DENTAL CARIES AND THE DISTRIBUTION OF BACTERIA ON THE SURFACE OF TEETH IN CHILDREN

In order to study the relation between dental caries and distribution of bacteria on the surface of teeth 45 childen with dental caries and 45 childen without dental caries were selected.All of them were five-eight year old. The results showed that 8 strains Streptococcus mutans, 6 Actinobacillus, and 26 Bacteroides were separeted in the group with dental caries; while no S.mutans and only 1 Actinobacillus. 14 Bacteroides were seperated in the group without dental caries;there was statistically significant diffence of distribution of the three types of bacteria between two groups(P<0 05). In addition 11 Corynebacterium and 7 Yersinia enterocolitica were seperated in the dental caries group,while 29 Corynebacterium were seperated in the dental caries group, while 29 Corynebacterium were seperated in the group without dental caries. It demonstrated that the distribution of facultative in the dental caries group was different from those in the group without dental caries. So we considered that the cause of dental caries was multiple factors,and it was the results of combined action of several bacteria.