Background Enamel demineralization occurs frequently during orthodontic treatment. In this study, we evaluated the changes of the density of mutans streptococcus (MS) in plaque after bracket bonding and using fluoride...Background Enamel demineralization occurs frequently during orthodontic treatment. In this study, we evaluated the changes of the density of mutans streptococcus (MS) in plaque after bracket bonding and using fluoride adhesive on maxillary incisors by real time fluorescence-quantitative polymerase chain reaction (RT-FQ PCR).Methods The study was designed as a self-paired test. Brackets were bonded with fluoride adhesive on the left side, while non-fluoride adhesive on the right side for each patient. Plaque samples were taken from the surfaces around the brackets of four maxillary incisors before brackets bonding and after the bonding 4 weeks later. The amount of MS was measured by RT-FQ PCR. The data obtained were analyzed statistically using the SPSS 11.5 version and the alpha level was set at 0.05 (2-tailed).Results The amount of MS in plaque increased significantly after bracket bonding (P<0.01), whereas no significant differences were observed among four maxillary incisors both before and after brackets bonding (P>0.05), and among the incisors using and not using fluoride adhesive (P>0.05).Conclusions The increase of the density of MS in plaque after bracket bonding is one of the etiological factors for enamel demineralization in orthodontic patients. The result of this study did not support what we observed clinically that the incidence of enamel demineralization for lateral incisors was higher than that for central incisors. Using fluoride adhesive for bonding did not affect the amount of MS in plaque in our study. Further study is needed.展开更多
基金supported in part by the National Natural Science Foundation of China under Grant Nos. 71171138,70871084the Specialized Research Fund for the Doctoral Program of Higher Education of China under Grant No.200806360001
文摘这篇论文从可靠性研究的观点与不可靠的加油站和多重适应推迟的假期认为排队的分离时间的 GeoX/G/1 是模型。后面的问题将被讨论：1 ) 服务者在在时间 n 的一个概括忙时期的概率；2 ) 加油站在在时间 n 的失败的概率，即，加油站的短暂 unavailability，和加油站的稳定的州的 unavailability；3 ) 加油站失败的期望的数字在时间间隔期间(0， n ] ，并且加油站的稳定的州的失败频率；4 ) 加油站故障在的期望的数字一概括的服务者忙碌时期。最后，作者证明有不可靠的加油站的一些普通分离时间的排队模型是在这篇论文讨论的模型的特殊情况。
文摘Background Enamel demineralization occurs frequently during orthodontic treatment. In this study, we evaluated the changes of the density of mutans streptococcus (MS) in plaque after bracket bonding and using fluoride adhesive on maxillary incisors by real time fluorescence-quantitative polymerase chain reaction (RT-FQ PCR).Methods The study was designed as a self-paired test. Brackets were bonded with fluoride adhesive on the left side, while non-fluoride adhesive on the right side for each patient. Plaque samples were taken from the surfaces around the brackets of four maxillary incisors before brackets bonding and after the bonding 4 weeks later. The amount of MS was measured by RT-FQ PCR. The data obtained were analyzed statistically using the SPSS 11.5 version and the alpha level was set at 0.05 (2-tailed).Results The amount of MS in plaque increased significantly after bracket bonding (P<0.01), whereas no significant differences were observed among four maxillary incisors both before and after brackets bonding (P>0.05), and among the incisors using and not using fluoride adhesive (P>0.05).Conclusions The increase of the density of MS in plaque after bracket bonding is one of the etiological factors for enamel demineralization in orthodontic patients. The result of this study did not support what we observed clinically that the incidence of enamel demineralization for lateral incisors was higher than that for central incisors. Using fluoride adhesive for bonding did not affect the amount of MS in plaque in our study. Further study is needed.
