自酸蚀粘接剂系统对变形链球菌的抑制作用

Antibacterial effect of self-etching adhesive systems on Streptococcus mutans

目的:研究不同自酸蚀粘接剂系统对变形链球菌(Streptococcus mutans,S.mutans)的抑制作用。方法:选用两步法自酸蚀粘接剂系统Clearfil^(TM)SE Bond预处理剂(SP)/粘接剂(SA)和Clearfil^(TM)Protect Bond预处理剂(PP)/粘接剂(PA),醋酸氯己定[chlorhexidine acetate,CHX,1%(质量分数)]设为阳性对照,磷酸盐缓冲液(phosphate buffer solution,PBS)设为阴性对照。将6种试剂与游离态S.mutan接触30 s后菌落计数;将6种试剂进行琼脂渗透实验,观察抑菌环;将CHX、PBS、SP和PP在生物人工龋坏牙本质盘上作用30 s,染色后使用激光共聚焦显微镜(confocal laser scanning microscope,CLSM)观察并计算活菌/死菌比例;在牙本质盘上使用两种自酸蚀粘接系统并固化,以空白牙本质盘作对照,滴加S.mutans培养2 h,菌落计数。使用非参数检验和单因素方差分析进行统计分析。结果:与PBS相比,SP、PP、SA、PA和CHX对游离态S.mutans均有抑制作用(P<0.05),SP和PP较SA、PA和CHX抑菌作用强(P<0.05),CHX、SP和PP均可见明显抑菌环,PBS、SA和PA未见明显抑菌环。与PBS相比,CHX、SP和PP作用后人工龋坏牙本质表面S.mutans活菌/死菌比例更低(P<0.05),两种自酸蚀粘接系统固化后对游离态S.mutans无明显抑制作用,与空白对照差异无统计学意义(P>0.05)。结论:自酸蚀粘接剂系统Clearfil^(TM)SE Bond和Clearfil^(TM)Protect Bond的预处理剂对游离态及黏附态S.mutans均具有显著抑制作用,其粘接剂在固化前对游离态S.mutans有抑制作用;两种自酸蚀粘接剂系统在牙本质表面使用并固化后,未能表现出明显抑菌性。

Objective： To investigate the antibacterial effect of different self-etching adhesive systems against Streptococcus mutans （S. mutans）. Methods： Six reagents ClearfilTM SE Bond primer （SP）, ClearfilTM SE Bond adhesive （SA）, ClearfilTM Protect Bond primer （PP）, which contained antibacterial monomer methacryloyloxydodecylpyridinium bromide （MDPB）, ClearfilTM Protect Bond adhesive （PA）, positive control chlorhexidine acetate [ CHX, 1% （mass fraction）], and negative control phosphate buffer solution （PBS） were selected. They were mixed with S. mutans for 30 s respectively, then colony- forming units （CFU） were counted after incubated for 48 h on brain heart infusion （BHI） agar medium. The 6 reagents were applied to the sterile paper discs, and distributed onto the BHI agar medium with S. mutans and incubated for 24 h, then the inhibition zones were observed. CHX, PBS, PP, and SP were added on the dentin with artificial caries induced by S. mutans and kept for 30 s, then confocal laser scanning microscope （CLSM） was used to observe the live and dead bacteria after staining. The ratio of live to dead bacteria was calculated. PP ＋ PA and SP ＋ SA were applied on the dentin according to the manual and light cured. S. mutans were incubated on the samples for 2 h, ultrasonically treated and in- cubated on BHI agar medium for 48 h, then CFU was counted. The data were analyzed by non-parametric analysis and one-way ANOVA. Results： Compared with PBS, the PP, SP, PAL, SA and CHX showed the antibacterial effect on free S. mutans （ P 〈 0.05 ） ; SP and PP showed stronger antibacterial effect than PA, SA and CHX （P 〈0.05）. CHX, SP and PP presented inhibition zones, while PBS, SA and PA did not. Compared with PBS, the CHX, SP and PP could lower the ratio of the live to dead bacteria significantly （ P 〈 0.05 ）. Cured self-etching adhesive systems did not show any antibacterial effect on the free S. mutaus. Conclusion：The primer of self-etching adhesives ClearfilTM SE Bond and ClearfilTM Pro- tect Bond showed significant antibacterial effect on free and attached S. mutans. The adhesive only showed antibacterial effect on free S. mutans before light-cured polymerization. After being cured, the self-etching adhesive systems did not show antibacterial effect anymore.