LED光照增强Ag_(2)O/TiO_(2)复合材料抗变异链球菌的作用机理

Mechanism of Ag_(2)O/TiO_(2) Composite Enhanced by LED Light against Streptococcus mutans

变异链球菌(Streptococcus mutans,S.mutans)感染是导致龋齿的主要原因。本研究将光催化剂Ag_(2)O/TiO_(2)复合材料与牙科常用的发光二极管(LED)固化灯相结合,探究了该材料在LED光照下对S.mutans的抗菌作用及机理。结果表明,Ag_(2)O/TiO_(2)复合材料在LED光照下抗菌作用显著增强,0.500 mg/mL Ag_(2)O/TiO_(2)在5 min照射后可将S.mutans全部杀死。进一步研究发现,Ag_(2)O/TiO_(2)在LED光照下产生羟基自由基(·OH)是抗菌活性增强的主要原因,材料产生的·OH进入细胞内,氧化生物大分子,从而导致细菌死亡。

Streptococcus mutans(S.mutans)infection is the main cause of caries.In this study,the photocatalyst Ag_(2)O/TiO_(2) com⁃posite was combined with light-emitting diode(LED)curing light commonly used in dentistry to explore the antibacterial effect and mechanism against S.mutans.The results showed that antibacterial effect of Ag_(2)O/TiO_(2) composite was significantly enhanced under LED light,and 0.500 mg/mL Ag_(2)O/TiO_(2) conbined with 5 min irradiation killed S.mutans completely.Further research found that the hydroxyl radical(·OH)produced by Ag_(2)O/TiO_(2) under LED irradiation was the main reason for the enhanced anti⁃bacterial activity.The·OH produced by the material entered the cells and oxidized the biomacromolecules,which resulted in the death of bacterial.