【作者】 张蕾； 邹朝晖； 陈阵； 马莹莹； 李敏；

【Author】 ZHANG Lei,ZOU Zhaohui,MA Yingying,LI Min(Dental Hospital of Tianjin Medical University,Tianjin,300070,China)

【机构】 天津医科大学口腔医院；

【摘要】 目的:探讨不同能量密度HMME—PDT对致龋模型中变形链球菌的杀伤效果及其安全性的影响。方法:通过在Wistar大鼠磨牙接种变形链球菌,构建大鼠致龋模型。将56只大鼠随机分成七组:能量密度8.4J/cm2、1 2.6J/cm2、1 6.8J/cm2PDT防龋处理组、单纯光敏剂组、单纯激光组、0.2%NaF阳性对照组、0.9%生理盐水阴性对照组。选择波长532 nm、功率密度140mw/cm2的半导体激光为光源,40μg/ml血卟啉单甲醚(HMME)为光敏剂。通过平板菌落计数法观察各组对变形链球菌的杀伤作用,组织病理观察大鼠口腔软组织变化。结果:平板菌落计数显示,与0.9%生理盐水阴性对照组相比,各PDT处理组均可使大鼠致龋模型口腔中变形链球菌数量(CFU/ml)显著减少(P<0.05),能量密度8.4J/cm2、12.6J/cm2、16.8J/cm2PDT防龋处理组的杀菌率分别为61.49%、96.91%、97.52%。其中能量密度12.6J/cm2、16.8J/cm2PDT组与能量密度8.4J/cm2PDT组相比杀菌率显著提高(P<0.05),而1 2.6J/cm2与1 6.8J/cm2之间没有显著性差异(P>0.05)。组织病理观察,与0.9%生理盐水阴性对照组比较,各PDT处理组均出现颊、舌粘膜充血水肿现象,但与8.4J/cm2PDT组和1 2.6J/cm2PDT组相比,1 6.8J/cm2PDT组中颊、舌粘膜充血水肿例数明显增多,还出现了轻度炎症细胞浸润和牙龈充血、角化层变厚现象。结论:HMME-PDT可有效杀灭大鼠口腔中的变形链球菌,其杀菌效果与能量密度关系密切。选择合适的能量密度,不仅可以提高灭菌率还可减少对口腔软组织的损伤。更多还原

【Abstract】 OBJECTIVE:To discuss the efficacy and safety of HMME-PDT with different energy density to Streptococcus mutans in cariogenic model.METHODS:To construct cariogenic model with Wistar rats by inoculating with Streptococcus mutans(S.mutans). Divided 56 rats into seven groups randomly:energy density with 8.4J/cm2、12.6J/ cm2、16.8J/cm2 of PDT group and the photosensitizer group,a simple laser group, 0.2%NaF positive control group,0.9%normal saline negative control group.Select the semiconductor laser with wave 532nm and power density of 140mw/cm2 as light source, 40μg/ml HMME as photosensitizer.Plate colony count observed in accordance with S.mutans suffer from tooth decay,through histopathological observation on oral soft tissue.RESULTS:Plate colony count showed that compared with the control group,PDT treatment on rats oral caries can significantly reduce the number of S.mutans(P <0.05), the sterilization rate of energy density with 8.4J/cm2、12.6J/cm2、16.8J/cm2 of PDT group were 61.49%、96.91%、97.52%,compared with the 8.4J/cm2 PDT group,the sterilization rate of 12.6J/cm2、16.8J/cm2 PDT group increased significantly(P <0.05), but there was no difference between 12.6J/cm2、16.8J/cm2 PDT group significantly (P>0.05).Histopathologic examination showed that compared with the control group ,the phenomenon of mucosal edema in every PDT groups,but compared with 8.4J/ cm2、12.6J/cm2 PDT groups,the case of mucosal edema in the 16.8J/cm2 PDT group increased significantly and occurred the mild inflammatory cell infiltration and gingival hyperemia,keratinized layer thickened phenomenon.CONCLUSION:HMME-PDT can kill the Streptococcus mutans in the rats oral cavity effectively,the bactericidal effect is related with the energy density closely.Select the appropriate energy density,not only can improve the sterilization rate may also reduce other oral tissue injury.更多还原