**2. Materials and Methods**

Two independent reviewers (Zhang and Got) conducted a literature search using the four most commonly used databases: Medline, PubMed, Embase, and Scopus. Only papers published in English were included. The keywords used were (silver diamine fluoride OR silver diamine fluoride OR SDF OR silver fluoride OR AgF AND biofilm OR plaque). No publication date limitation was established during the search. The latest search was conducted on 30 October 2020.

The inclusion criteria were as follows: (1) papers investigating biofilm; (2) SDF solution at any concentration adopted as an intervention. The exclusion criteria were (1) studies with no information concerning biofilm and (2) reviews, case reports, and conference papers. In addition, a manual search of the reference lists of the selected papers and review articles was conducted. The two reviewers independently screened the papers and identified the relevant studies. When a disagreement occurred, another researcher (Chu) was consulted to achieve a consensus.

The results were summarized into three tables classified by the aim of the studies: Table 1 is for the studies investigating the effect of SDF on biofilm formed via microbiota, Table 2 is for the studies on the diversity and microbial change resulting from the application of SDF, and Table 3 is for the studies focused on the effect of SDF on fungus. Information regarding the following aspects of the background of the included studies was extracted and is presented in the summary tables: (1) authors and year; (2) materials studied; (3) setting of the study; (4) block (or sample) adopted in the study; (5) microbiota studied; (6) assessing method for the biofilm; (7) duration of the study; and (8) findings of the study.


**Table 1.** Studies on the antibacterial effect of silver diamine fluoride (SDF).


**Abbreviations:** Gp, group; CFU, colony forming unit; CLSM, confocal laser scanning microscopy (dead-to-live ratio); NaCl, sodium chloride; BL, baseline; Ca(OH)2, calcium hydroxide; NaOCl, sodium hypochlorite; TBC, total bacteria count; APF, acidulated phosphate fluoride; AHF, ammonium hexafluorosilicate; CPC, cetylpyridinium chloride; CHX, chlorhexidine; NaF, sodium fluoride; N/T, no treatment; NSF, nano silver fluoride; PPF, propolis fluoride; KI, potassium iodide; AgNO3,silver nitrate; SP, severe periodontitis; TVC, total viable counts; PLPP, proportional levels of periodontal pathogens; MALDI-TOF, matrix-assisted laser desorption/ionization time-of-flight.

**Table 2.** Microbiota change within biofilm after silver diamine fluoride treatment.


**Abbreviations:** BL, baseline; LMER, linear mixed effects regression; OTU, operational taxonomic unit.


**Table 3.** Studies on the antifungal effect of silver diamine fluoride.

**Abbreviations:** CQ, colorimetric quantification; Rt-PCR, real-time PCR-based quantification; SEM, scanning electron microscopy; ZGI, zones of growth inhibition; Multi-PCR, multiplex PCR; MIC, minimal inhibitory concentration; UI, ultrastructural image.

## **3. Results**

A total of 540 potentially relevant records were identified through the database search, and 194 were left after the removal of duplicates. A manual search of the references of these selected publications was conducted. One article that met the inclusion criteria was added to the list. After the titles and abstracts were screened, 133 records were excluded. The remaining 62 papers, all published in English, were retrieved for full-text reading. Among them, 20 articles did not report microbial analysis and 21 did not contain biofilm or microbiome information.

Among the 21 papers included, six were laboratory studies and 15 were clinical studies. The 21 included papers were published between 2010 and 2020. An SDF solution concentration of 38% was reported in 16 studies, followed by 3.8% SDF in three studies and 25% SDF, or 8.5 wt%, in the other studies. Figure 1 is a flowchart showing the search results.

#### *3.1. Application of Silver Diamine Fluoride on Bacteria*
