METHODS: Biofilms of Streptococcus mutans strains (ATCC 25,175) were cultivated on bovine tooth blocks and exposed to a 10% sucrose solution three times a day for 1 min over three consecutive days. The samples were randomly distributed into five treatment groups (n = 5): (I) aPDT with ClAlPc/Ch with a preirradiation time of 5 min (F5), (II) aPDT with ClAlPc/Ch with a preirradiation time of 15 min (F15), (III) aPDT with ClAlPc/Ch with a preirradiation time of 30 min (F30), (IV) 0.12% chlorhexidine digluconate (CHX), and (V) 0.9% saline solution (NaCl). After treatment, the S. mutans biofilms formed on each specimen were collected to determine the number of viable bacteria (colony-forming units (CFU)/mL). Data were analyzed for normality using the Shapiro-Wilk test and the analysis of variance (ANOVA) and Tukey HSD tests to analyze the number of viable bacteria (α = 0.05).
RESULTS: The one-way ANOVA showed a difference between the groups (p = 0.0003), and the Tukey HSD posttest showed that CHX had the highest microbial reduction of S. mutans, not statistically different from the F5 and F15 groups, whereas the NaCl group had the lowest microbial reduction statistically similar to the F30 group.
CONCLUSIONS: The results demonstrate that aPDT mediated by ClAlPc/Ch when used at preirradiation times of 5-15 min can be an effective approach in controlling cariogenic biofilm of S. mutans, being an alternative to 0.12% CHX.
方法:在牛牙块上培养变形链球菌菌株(ATCC25,175)的生物膜,并在连续三天内每天三次暴露于10%蔗糖溶液1分钟。将样品随机分为五个处理组(n=5):(I)使用ClAlPc/Ch进行aPDT,预照射时间为5分钟(F5),(II)使用ClAlPc/Ch的aPDT,预照射时间为15分钟(F15),(III)使用ClAlPc/Ch的aPDT,预辐照时间为30分钟(F30),(IV)0.12%二葡萄糖酸氯己定(CHX),和(V)0.9%盐水溶液(NaCl)。治疗后,收集在每个样本上形成的变形链球菌生物膜以确定活细菌的数量(菌落形成单位(CFU)/mL)。使用Shapiro-Wilk检验和方差分析(ANOVA)和TukeyHSD检验分析活菌数(α=0.05)来分析数据的正态性。
结果:单向方差分析显示各组之间存在差异(p=0.0003),TukeyHSD后测显示CHX对变形链球菌的微生物减少量最高,与F5和F15组没有统计学差异,而NaCl组的微生物减少率最低,统计学上与F30组相似。
结论:结果表明,在5-15分钟的预照射时间使用时,由ClAlPc/Ch介导的aPDT可以是控制变形链球菌致龋生物膜的有效方法,是0.12%CHX的替代品。