目的

探讨8 ～32 个月婴幼儿牙菌斑中乳杆菌的检出情况，了解乳杆菌与龋病的关系。

方法

基线募集广州市花都区新华镇225 名8 个月龄婴幼儿，对其进行龋病检查和牙菌斑样本收集，之后每6 个月重复1 次至32 个月龄。 采用Rogosa 选择性培养基作乳杆菌的分离培养并鉴定。 χ² 检验比较不同性别、年龄和不同患龋状况婴幼儿乳杆菌检出情况。

结果

8、14、20、26 和32 个月龄婴幼儿乳杆菌检出率分别为12.0%、5.6%、11.0%、9.3%和21.3%，32 个月龄乳杆菌检出率高于14 和26 个月龄，各年龄组中男女童乳杆菌的检出率无差别。 乳杆菌阳性个体在5 次样本检测中，72.3%仅为1 次阳性。 各年龄组患龋婴幼儿乳杆菌检出率均显著高于无龋组。

结论

婴幼儿口腔中乳杆菌检出较早，但在牙面定植不稳定，随年龄的增长和龋病患病的变化而变化。

Objective

The objective of this longitudinal study was to investigate the presence of lactobacilli in 8-32 month old children and the relationship between the presence of lactobacilli and dental caries.

Methods

Dental caries was examined and dental plaque samples were collected from 225 children of 8 month old in Xinhua Town， Huadu District of Guangzhou at baseline， and follow-ups were conducted every 6 months until they were 32 months old. Dental plaque samples were plated onto Rogosa selective media for incubation and identification of lactobacilli. Chi-square test was performed to compare the presence of lactobacilli among children with different genders， ages and dental caries status.

Results

The prevalence of lactobacilli colonization in the children examined was 12.0%， 5.6%， 11.0%， 9.3% and 21.3%， at the age of 8， 14， 20， 26， and 32 months， respectively. The prevalence at 32 months was higher than that at 14 and 26 months. There was no significant difference between boys and girls. In the children who had ever been detected with lactobacilli in baseline and the 4 times of follow-up， 72.3%were only positive in one time point. The prevalence of lactobacilli in the children with dental caries was significantly higher than that in caries-free group.

Conclusions

Lactobacilli colonized in teeth surfaces in early age， but the colonization is unstable and changes with age and the presence of caries.