What do systematic reviews say?

Silver diamine fluoride (SDF) vs placebo or no treatment

• Topical silver diamine fluoride (SDF) for preventing and managing dental caries in children and adults 2024 · Cochrane All outcomes

  12 to 30 months · Adults
  1 study reported no adverse effects. 1 study reported a white discolouration of the gingiva adjacent to surfaces treated with SDF (116 surfaces) as well as redness (4 surfaces), and mild ulceration (2 surfaces). In…
  2 studies · 316 participants
  Very low
• Topical silver diamine fluoride (SDF) for preventing and managing dental caries in children and adults 2024 · Cochrane All outcomes

  48 hours to 30 months · Children
  1 study reported 3 adverse effects in the first 48 hours. Of these, 1 effect in SDF group was possibly related to treatment (spot on corner of lip that looked like a burn), and 2 effects in placebo group were possibly…
  3 studies · 983 participants
  Very low

Patient-used 250 ppm F mouthrinse (100 ppm amine F/150 ppm NaF), daily vs 0 ppm F placebo mouthrinse, daily

The review found no eligible studies for this question.

• Fluorides for preventing early tooth decay (demineralised lesions) during fixed brace treatment 2019 · Cochrane All outcomes

  At debond (end of orthodontic treatment)
  SoF 4. Adverse effects: none of the trials reported this outcome.
  0 studies
  No studies found

12,500 ppm F (NaF/olaflur/dectaflur) amine fluoride gel vs Placebo gel

• Fluorides for preventing early tooth decay (demineralised lesions) during fixed brace treatment 2019 · Cochrane All outcomes

  At debond; mean follow-up 16.6 months
  Additional SoF Table 1. Adverse effects: with placebo gel 0.60%; with fluoride gel 0.00% (0 to 0); difference 0.60% fewer (0.60 fewer to 0.60 fewer); relative effect not estimable; 312 participants (1 RCT); certainty…
  1 study · 312 participants
  Very low

Professionally-applied 12,300 ppm F APF foam, every 2 months vs 0 ppm F placebo foam

The review found no eligible studies for this question.

• Fluorides for preventing early tooth decay (demineralised lesions) during fixed brace treatment 2019 · Cochrane All outcomes

  At debond (end of orthodontic treatment)
  SoF 2. Adverse effects: none of the trials reported this outcome.
  0 studies
  No studies found

Fluoride varnish vs Non-fluoride (placebo) varnish

• Fluorides for preventing early tooth decay (demineralised lesions) during fixed brace treatment 2019 · Cochrane All outcomes

  At debond; follow-up 1.7 years
  SoF 1. Adverse effects: no evidence that the intervention had adverse effects; only 1 participant with an adverse event and unclear if directly related to the intervention. 148 participants (1 RCT, Sonesson 2019);…
  1 study · 148 participants
  Low

Flossing plus toothbrushing (self-performed; manual or automated floss) vs Toothbrushing alone

• Flossing for the management of periodontal diseases and dental caries in adults 2011 · Cochrane All outcomes
  Not estimable (5 studies). Adverse effects were assessed in five studies, but they used different outcome measures, so meta-analysis was not appropriate. The main harm identified was soft-tissue trauma to the gingival…
  5 studies
  GRADE not reported

1500 ppm F toothpaste vs Non-fluoride (0 ppm F) placebo toothpaste

• Fluoride toothpastes of different concentrations for preventing dental caries 2019 · Cochrane All outcomes

  24 months
  Adverse effects of toothpaste: not estimable; 0 events reported (Fan 2008); 998 participants (1 RCT); low-certainty.
  1 study · 998 participants
  Low

1000 or 1100 ppm F toothpaste vs Non-fluoride (0 ppm F) placebo toothpaste

The review found no eligible studies for this question.

• Fluoride toothpastes of different concentrations for preventing dental caries 2019 · Cochrane All outcomes
  Adverse effects of toothpaste: no studies reported this outcome.
  0 studies
  No studies found

Fluoride mouthrinse (0.05-0.32% sodium fluoride or amine fluoride) added to daily fluoride toothpaste vs Control: fluoride toothpaste alone, placebo mouthrinse + toothpaste, or non-fluoride (chlorhexidine) mouthrinse + toothpaste

No adverse effects were reported in any of the seven included studies (ungraded).

• Fluoride mouthrinses for prevention of initial caries in orthodontic patients - a systematic review and meta-analysis. 2025 All outcomes

  During treatment · Clinical orthodontic (fixed multi-bracket appliance) treatment
  No side- or adverse effects were reported in any of the included reports.
  7 studies · 704 participants
  GRADE not reported

Fluoride supplementation (tablets, drops, lozenges or chewing gum) vs placebo or no treatment

• Fluoride supplementation (with tablets, drops, lozenges or chewing gum) in pregnant women for preventing dental caries… 2017 · Cochrane All outcomes
  no estimate extracted
  1 study
  GRADE not reported

Silver diamine fluoride (SDF) vs Other methods (pooled: ART/glass ionomer cement, nano-silver fluoride, sodium fluoride varnish, placebo)

SDF commonly causes black staining of arrested lesions; only mild, transient adverse events were reported, with no major adverse events (ungraded).

• The role of silver diamine fluoride as dental caries preventive and arresting agent: a systematic review and… 2024 All outcomes

  up to 30 months · Children/adults with dental caries; multiple countries; community/clinic care setting not clearly specified
  Black staining of arrested lesions reported in most studies; 4 studies reported mild transient events (gingival blenching/pain; diarrhea/stomachache; burning, bad taste, pain, mouth injury, dissatisfaction with…
  Studies not reported
  GRADE not reported

Xylitol lozenges (5 g/day) vs placebo control

• Xylitol‐containing products for preventing dental caries in children and adults 2015 · Cochrane All outcomes

  33 months
  Patterns of adverse effects (sores in the mouth, cramps, bloating, constipation, flatulence, and loose stool or diarrhoea) were similar for both groups. Bader 2013.
  1 study · 669 participants
  GRADE not reported

Topical fluoride therapy (toothpaste, mouthrinse, gel or varnish; any fluoride agent/concentration; frequency at least once a year) vs placebo or no treatment

• Topical fluoride (toothpastes, mouthrinses, gels or varnishes) for preventing dental caries in children and adolescents 2003 · Cochrane All outcomes
  Data on adverse effects (stain score, proportion of children with tooth staining, signs of sensitivity in oral soft tissue, adverse symptoms such as nausea/vomiting, etching of enamel) were reported in only a few…
  Studies not reported
  GRADE not reported

Fluoride varnish vs placebo or no treatment

• Fluoride varnishes for preventing dental caries in children and adolescents 2013 · Cochrane All outcomes

  At least 1 year
  Three trials (Salazar 2008; Skold 2005; Weintraub 2006) provided data reporting no adverse effects. There was little information concerning possible adverse effects; no pooled estimate was possible.
  3 studies
  GRADE not reported