Yonsei University College of Dentistry, Oral Science Research Institute, Department of Preventive De, Republic of Korea.
University of Liverpool, School of Dentistry, Department of Health Services Research, Liverpool, United Kingdom.
J Biomed Opt. 2018 Jan;23(1):1-6. doi: 10.1117/1.JBO.23.1.015003.
The study aimed to determine whether the red fluorescence (RF) of a dental microcosm biofilm as measured with quantitative light-induced fluorescence (QLF) technology is useful for assessing the efficacy of antimicrobials. Dental microcosm biofilms were formed on bovine enamel discs and grown under 0.3% sucrose challenge and treated with chlorhexidine (CHX) solutions at different concentrations (0.05%, 0.1%, and 0.5%) plus a negative control [sterile distilled water (DW)] twice daily for 7 days. The biofilms were photographed using a QLF-digital system to evaluate the RF by calculating the red/green ratio, and pH values of the medium were measured daily. After 7 days, the bacterial viability of the biofilm was assessed by measuring the counts of viable total bacteria and aciduric bacteria, and the percentage surface microhardness changes (%SHC) was evaluated. The RF and cariogenic properties were compared for the different concentrations of CHX, and their correlations were examined. The RF and its increase rate were much lower for CHX-treated biofilms than for DW-treated biofilms. The RF after 7 days of maturation decreased significantly with increasing CHX concentrations (p<0.001) and was from 31% (for 0.05% CHX) to 46% (for 0.5% CHX) lower than that of the DW group. Strong correlations were reported between the RF of the 7-day-maturation biofilms and cariogenic properties, such as the number of total bacteria (r=0.93), number of aciduric bacteria (r=0.97), supernatant pH (r=0.43), and %SHC (r=0.98). In conclusion, the RF of dental biofilms as measured with QLF technology can be used to nondestructively assess and monitor the effect of antimicrobials against biofilm.
本研究旨在确定定量光致荧光（QLF）技术测量的牙菌斑微生物膜的红色荧光（RF）是否可用于评估抗菌剂的功效。在 0.3%蔗糖挑战下，在牛牙釉质圆盘上形成牙菌斑微生物膜，并在 0.05%、0.1%和 0.5%的洗必泰（CHX）溶液及阴性对照[无菌蒸馏水（DW）]的作用下，每天两次处理，共处理 7 天。使用 QLF 数字系统拍摄生物膜照片，通过计算红/绿比来评估 RF，并每天测量培养基的 pH 值。7 天后，通过测量总活菌和耐酸菌的计数来评估生物膜的细菌活力，并评估表面显微硬度变化百分比（%SHC）。比较了不同浓度 CHX 的 RF 和致龋特性，并检查了它们之间的相关性。与 DW 处理的生物膜相比，CHX 处理的生物膜的 RF 及其增长率要低得多。7 天成熟后，随着 CHX 浓度的增加，RF 显著降低（p<0.001），与 DW 组相比，RF 分别降低了 31%（0.05% CHX）和 46%（0.5% CHX）。报告称，7 天成熟生物膜的 RF 与致龋特性（如总菌数（r=0.93）、耐酸菌数（r=0.97）、上清液 pH（r=0.43）和%SHC（r=0.98））之间存在很强的相关性。总之，QLF 技术测量的牙菌斑生物膜的 RF 可用于非破坏性评估和监测抗菌剂对生物膜的作用。
