目的研究甲苯胺蓝介导的光动力学疗法对体外人工菌斑生物膜形成的影响,探讨光动力学疗法控制菌斑和防治龋病的可能机制。方法体外环境下,4种口腔常见致龋菌在牙釉质表面形成多细菌混合性菌斑生物膜,用光动力学疗法处理实验组菌斑生物膜,光敏剂浓度为0.1mg/ml、光强为94.5J/cm2;分别在生物膜形成的第1、3、7天用扫描电镜观察光动力学疗法处理对生物膜形成的影响。结果对照组第1天可见到以链球菌为主的细菌黏附于获得性膜上;第3天各种细菌数量明显增多,形成谷穗状结构;至第7天时,生物膜形成复杂的三维立体结构,细菌表面及细菌之间可见大量基质和不定形胶状物。在第1、3、7天,光动力学疗法处理后牙釉质表面黏附的细菌显著减少,菌斑生物膜形成受阻。结论光动力学疗法对菌斑生物膜的形成有抑制作用。 Objective To investigate the effect of toluidine blue-mediated photodynamic therapy on the formation of artificial plaque biofilm in vitro and to explore the possible mechanisms by which photodynamic therapy can control plaque and prevent dental caries. Methods Four kinds of oral cariogenic bacteria were used to form multi-bacteria mixed plaque biofilms on the surface of enamel in vitro. Photodynamic therapy was used to treat the plaque biofilms in the experimental group. The concentration of photosensitizer was 0.1 mg / ml, Was 94.5J / cm2. The effects of photodynamic therapy on biofilm formation were observed by scanning electron microscopy on the 1st, 3rd and 7th day of biofilm formation respectively. Results The streptococcal bacteria adhered to the acquired membrane on the first day of the control group. On the third day, the number of all kinds of bacteria increased obviously, forming the spike-like structure. By the seventh day, the biofilm formed complex three-dimensional Structure, bacterial surface and bacteria can be seen between a large number of matrix and amorphous jelly. On the 1st, 3rd and 7th day, the adhesion of bacteria to the enamel surface after photodynamic therapy was significantly reduced, and the formation of plaque biofilm was blocked. Conclusion Photodynamic therapy can inhibit the formation of plaque biofilm.