Deng Dong Mei, Buijs Mark J, ten Cate Jacob M
Department of Cariology Endodontology Pedodontology, Academic Center for Dentistry Amsterdam (ACTA), Amsterdam, The Netherlands.
Eur J Oral Sci. 2004 Feb;112(1):42-7. doi: 10.1111/j.0909-8836.2004.00100.x.
Antimicrobial agents are now being studied in bacterial biofilms rather than in suspensions. However, no data are available whether the choice of substratum influences biofilm properties or the assessment of antimicrobial efficacy. This study compared dentin and polyacrylate (PA) grooves as substratum for biofilm formation on pH profiles after sugar challenge, as well as biofilm susceptibility to chlorhexidine. Streptococcus mutans biofilms were formed in a constant depth film fermenter (CDFF) by alternate pulsing with sucrose solutions and bacterial growth medium. Spatial and temporal pH profiles were measured using a pH microelectrode outside the CDFF in a flow reactor. Also, 15-d biofilms were treated with either water or 0.2% chlorhexidine and tested for total viable counts and organic acid content. The results show that in PA grooves, compared with dentin grooves, minimum pH was lower but recovered faster after a sucrose pulse. The pH response to sugar application decreased with the age of the biofilm more in PA than in dentin grooves. Chlorhexidine treatment in PA grooves gave greater reductions in viable counts and acid formation than in dentin. We conclude that the nature of the substratum not only affects metabolic activity of biofilms but also their susceptibility to antimicrobials.
目前，抗微生物剂的研究是针对细菌生物膜而非悬浮液进行的。然而，关于基质的选择是否会影响生物膜特性或抗微生物功效评估，尚无相关数据。本研究比较了牙本质和聚丙烯酸酯（PA）凹槽作为基质在糖刺激后pH曲线方面的生物膜形成情况，以及生物膜对氯己定的敏感性。变形链球菌生物膜通过在恒定深度膜发酵罐（CDFF）中交替注入蔗糖溶液和细菌生长培养基形成。使用流动反应器中CDFF外部的pH微电极测量空间和时间pH曲线。此外，用去离子水或0.2%氯己定处理15天龄的生物膜，并检测其总活菌数和有机酸含量。结果表明，在PA凹槽中，与牙本质凹槽相比，最低pH较低，但在蔗糖脉冲后恢复更快。在PA凹槽中，生物膜对糖施加的pH反应随生物膜年龄的增加而下降的幅度比牙本质凹槽更大。PA凹槽中的氯己定处理比牙本质凹槽中的活菌数和酸形成减少得更多。我们得出结论，基质的性质不仅影响生物膜的代谢活性，还影响其对抗微生物剂的敏感性。
