固定正畸过程中牙面菌群变化与釉质脱矿相关性研究

摘要

目的 初步探讨牙面托槽周围变形链球菌、放线菌、乳杆菌菌群数量及其在总菌群中所占比例的变化,与固定正畸过程中釉质脱矿之间的相关性.方法 随机选取正在进行固定正畸矫治、且出现上前牙(A3-B3)牙面釉质脱矿的患者26例(脱矿组),以及正在进行固定正畸矫治、但没有出现明显上前牙脱矿的患者49例(未脱矿组),刮取每个患者的上颌切牙托槽龈侧面菌斑,分别进行变形链球菌、放线菌和乳杆菌的分离培养,计算各患者所取菌斑中这3种细菌的数目及其占检出细菌总量的比例;检测取样牙位的软垢指数.分析比较脱矿组与未脱矿组上述测量指标的差异性.结果 脱矿组与未脱矿组软垢指数差异无统计学意义(P＞0.05);脱矿组变形链球菌数目及所占细菌总量的比例均明显增高(P＜0.05),而两组间放线菌、乳杆菌数目及所占细菌总量的比例无明显差异性(P＞0.05).结论 牙面托槽周围菌斑中所含变形链球菌数目及所占总菌群的比例增高,可能是固定正畸过程中牙齿表面脱矿的机制之一.%Objective To preliminarily discuss the changes in the quantity of streptococcus mutatis, actinomycetes, and bacterium lacticum and their proportions in the total microbial population around the bracket on facing, and analyze the correlation between the changes and enamel demineralization during fixed orthodontic treatment. Methods Twenty - six patients undergoing fixed orthodontic treatment who had enamel demineralization on maxillary incisors ( demineralization group ) and 49 patients undergoing the same treatment but without significant enamel demineralization ( no demineralization group ) were randomly selected. Bacteria plaque specimens near the bracket on the incisors of upper jaw were scraped in order to carry out the fractional cultivation of streptococcus mutans, actinomycetes, and bacterium lacticum. The amount of those bacteria and their proportion in the total amount of the detected bacteria in the specimens were calculated. And the debris index of the sampled tooth was also analyzed. Analysis and comparison were made in the differences in the above indexes between the two groups. Results There was no significant difference in debris index between two groups ( P > 0. 05 ). In the demineralization group, the quantity and the proportion of streptococcus mutans in the total bacteria significantly increased ( P < 0. 05 ). There was no significant difference in the quantity and proportion of actinomycete and bacterium lacticum between the two groups ( P > 0. 05 ). Conclusion The increasing quantity and proportion of streptococcus mutans in the bacterial plaque around the bracket on the facing may be one of the mechanisms for the enamel demineralization during fixed orthodontic treatment.