鼻咽癌放疗后人群菌斑细菌含量与龋病的相关性分析

Correlation analysis of bacterial content in plaque and caries of nasopharyngeal carcinoma patients after radiotherapy

目的分析鼻咽癌放疗后人群菌斑总菌量及变形链球菌量与龋失补牙面数(DMFS)的相关关系,筛查鼻咽癌放疗后人群龋病高发的危险因素。方法随机抽取193例鼻咽癌放疗后患者为样本人群,口腔检查其患龋情况。收集非龋光滑面牙菌斑,荧光定量聚合酶链反应(RT-PCR)测定菌斑总菌及变形链球菌含量,Spearman相关分析总菌量、变形链球菌量及变形链球菌占总菌量的百分比与DMFS的相关关系。结果鼻咽癌放疗后人群不同牙位的患龋率存在差异,菌斑总菌量、变形链球菌量及变形链球菌占总菌量的百分比与DMFS间无线性相关关系(P>0.05)。结论鼻咽癌放疗后人群放射性龋存在好发牙位,菌斑细菌含量并非放射性龋的主要危险因素,推测放射性龋可能主要与细菌质的改变有关。

Objective To analyze the correlation between levels of total bacteria,Streptococcus mutans in dental plaque and decay missing filling surface（DMFS） index of nasopharyngeal carcinoma（NPC） patients after radiotherapy.And to screen risks of radiation caries in NPC patients.Methods One hundred and ninety-three NPC patients after radiotherapy were randomly selected for the study.Clinical examination was conducted to obtain the prevalence of caries and DMFS.Dental plaque on the smooth surface without caries were collected and analyzed by RT-PCR.The correlation between DMFS index and total bacteria,Streptococcus mutans as well as percentage of Streptococcus mutans was analyzed.Results Prevalence rate among different teeth are not the same incompletely.There was no linear correlation between DMFS index and total bacteria,Streptococcus mutans as well as percentage of Streptococcus mutans（P 0.05）.Conclusions Radiation caries of NPC patients after radiotherapy has higher prevalence teeth.Bacterial content in plaque is not the major contributor of radiation caries,suggesting that changes of acid producing ability of bacteria and genotypes of Streptococcus mutans may be related to radiation caries.