摘　要：光学参数如波长、功率密度、照射时间等可显著影响光疗的杀菌效果。本研究旨在探索LED光疗抑制口腔细菌增殖的最佳光学参数，为临床口腔细菌感染性疾病的光学治疗提供参考。将粪肠球菌（Enterococcus faecalis）和牙龈卟啉单胞菌（Porphyromonas gingivalis）菌液接种于96孔板中，用峰值波长为405 nm和455 nm的自制LED光源，以10 mW/cm2和40 mW/cm2的功率密度，在能量密度9.6～33.6 J/cm2的范围内对其进行光照，30 min后以活死菌荧光染色或平板涂布法检测光疗杀菌效果。结果发现：405/455 nm波长LED光照对两种厌氧菌均有显著的杀伤效果；牙龈卟啉单胞菌在波长为405 nm、功率密度为40 mW/cm2、光照能量为33.6 J/cm2的LED光照下达最大抑菌率（96.05±1.80）%；粪肠球菌则在波长为405 nm、功率密度为10 mW/cm2、光照能量为33.6 J/cm2时达到最佳抑菌效果（97.64±2.31）%。研究表明，适宜的光学参数可使LED光照对口腔常见致病菌产生显著的抑菌效果。在本研究条件下，波长为405 nm、照射剂量为33.6 J/cm2的参数组合效果最佳。
关键词：LED光疗；内源性光敏剂；粪肠球菌；牙龈卟啉单胞菌；口腔感染
中图分类号：Q935；R318.51                   文献标志码：A            DOI：10.3969/j.issn.1007-7146.2022.02.002

Abstract: Optical parameters such as wavelength, power density and irradiation time have important effects on the bactericidal effect of phototherapy. This study aimed to explore the optimal optical parameters of LED phototherapy to inhibit the proliferation of oral bacteria, and provide a basis for the formulation of optical therapy for clinical oral bacterial infectious diseases. Enterococcus faecalis and Porphyromonas gingivalis were inoculated in 96-well plates and irradiated with the self-made 405 nm LED and 455 nm LED with power densities of 10 mW/cm2 and 40 mW/cm2. Energy densities of the LEDs ranged from 9.6 to 33.6 J/cm2. After 30 min, the bactericidal effect of phototherapy was evaluated by bacterial fluorescent staining or plate counting. The results showed that 405/455 nm LED had significant bactericidal effects on both kinds of bacteria. The maximum bacteriostatic rate (96.05±1.80)% of P. gingivalis was achieved with 405 nm LED with 40 mW/cm2 at light dose of 33.6 J/cm2. The maximum bacteriostatic rate (97.64±2.31)% of E. faecalis was achieved with 405 nm LED with 10 mW/cm2 at light dose of 33.6 J/cm2. It indicated that LED illumination can achieve significant bacteriostatic effects on common oral pathogens with appropriate optical parameters, while 405 nm LED with light dose of 33.6 J/cm2 could achieve the best effect in the study.
Key words: LED phototherapy; endogenous photosensitizer; Enterococcus faecalis; Porphyromonas gingivalis; oral infection
（Acta Laser Biology Sinica, 2022, 31(2): 104-113）