Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, 1-8 Yamadaoka, Suita, Osaka, 565-0871, Japan.
Division of Cariology, Operative Dentistry, and Endodontics, Department of Oral Health Science, Niigata University Graduate School of Medical and Dental Sciences, Niigata, 951- 8514, Japan.
Sci Rep. 2022 May 6;12(1):7435. doi: 10.1038/s41598-022-11477-1.
Silver diamine fluoride (SDF) has been long studied in laboratories, and its clinical effectiveness in the treatment and prevention of root caries has been reported. In the present study, we assessed the microbiological effects of SDF on dental biofilms grown on demineralized dentin in situ. Specifically, demineralized bovine root dentin slabs used as biofilm substrates were treated with 38% SDF, and the biofilms formed after this treatment were analyzed via real-time PCR, DEAD/LIVE cell staining, and SEM. Next, the viable cell count was determined, and microbial profiles were compared using 16S rRNA gene sequencing. Untreated slabs were used as controls. We observed significant decreases in viable cell counts (p < 0.05), number of biofilm-forming cells (p < 0.01), biofilm thickness (p < 0.01), and high proportion of dead cells with SDF treatment (p < 0.01). The microcolonies in the SDF-treated biofilms showed less complexity, and only a limited number of genera were differentially abundant between the groups. Microbial diversity index comparisons showed no significant differences between the groups with respect to treatments days (p = 0.362). Thus, SDF negatively influenced dental biofilm growth on demineralized root dentin in situ; however, its antimicrobial action did not target a specific oral taxon.
银胺氟化物（SDF）在实验室中已经研究了很长时间，其在治疗和预防根面龋中的临床效果已有报道。本研究评估了 SDF 对原位脱矿牙本质上形成的牙菌斑的微生物学影响。具体来说，使用脱矿牛根牙本质片作为生物膜底物进行 38%SDF 处理，然后通过实时 PCR、DEAD/LIVE 细胞染色和 SEM 分析处理后形成的生物膜。接下来，通过 16S rRNA 基因测序确定活菌计数，并比较微生物谱。未处理的板用作对照。我们观察到活菌计数显著减少（p<0.05），生物膜形成细胞数量减少（p<0.01），生物膜厚度减少（p<0.01），以及 SDF 处理后死亡细胞比例高（p<0.01）。SDF 处理的生物膜中的微菌落显示出较低的复杂性，并且只有少数属在组间存在差异丰度。微生物多样性指数比较显示，处理天数之间组间无显著差异（p=0.362）。因此，SDF 对原位脱矿牙本质上的牙菌斑生长有负面影响；然而，其抗菌作用并非针对特定的口腔分类群。
