What do systematic reviews say?

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

• Fluoride toothpastes for preventing dental caries in children and adolescents 2003 · Cochrane All outcomes

  At least 1 year
  Oral soft tissue lesions reported in 3 trials, none of which with complete or useable data; all three stated "no lesions attributable to product use were noted".
  3 studies
  GRADE not reported

Dental caries vs Caries-free status

Across the combined sample set, alpha-diversity metrics were significantly higher in caries than in health, but no pooled effect estimate was reported.

• Meta-analysis of caries microbiome studies can improve upon disease prediction outcomes. 2022 All outcomes

  Human oral samples
  Higher alpha diversity in caries than health; p<0.001 (Wilcoxon; no pooled effect size reported)
  19 studies · 2016 participants
  GRADE not reported

Dental caries vs Caries-free status

Phosphonate and phosphinate metabolism and glyoxylate and dicarboxylate metabolism had the lowest reported adjusted P values (0.04); no pooled effect estimate was reported.

• Meta-analysis of caries microbiome studies can improve upon disease prediction outcomes. 2022 All outcomes

  Human oral samples
  no estimate extracted
  19 studies · 2016 participants
  GRADE not reported

Dental caries vs Caries-free status

Beta-diversity matrices showed statistically significant ADONIS results, while clustering by study and 16S region was also observed; no pooled effect estimate was reported.

• Meta-analysis of caries microbiome studies can improve upon disease prediction outcomes. 2022 All outcomes

  Human oral samples
  no estimate extracted
  19 studies · 2016 participants
  GRADE not reported

Pre-radiotherapy extraction of healthy molar teeth vs Conservative treatment (leaving the teeth in place during radiotherapy, with oral health education and disease prevention: oral hygiene, fluoride, diet advice)

The review found no eligible studies for this question.

• Dental extractions prior to radiotherapy to the jaws for reducing post‐radiotherapy dental complications 2013 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Pre-radiotherapy extraction of diseased molar teeth vs Conservative treatment (restoration of the teeth and leaving them in place during radiotherapy, with oral health education and disease prevention: oral hygiene, fluoride, diet advice)

The review found no eligible studies for this question.

• Dental extractions prior to radiotherapy to the jaws for reducing post‐radiotherapy dental complications 2013 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Pre-radiotherapy extraction of healthy molar teeth vs Conservative treatment (leaving the teeth in place during radiotherapy, with oral health education and disease prevention: oral hygiene, fluoride, diet advice)

The review found no eligible studies for this question.

• Dental extractions prior to radiotherapy to the jaws for reducing post‐radiotherapy dental complications 2013 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Pre-radiotherapy extraction of diseased molar teeth vs Conservative treatment (restoration of the teeth and leaving them in place during radiotherapy, with oral health education and disease prevention: oral hygiene, fluoride, diet advice)

The review found no eligible studies for this question.

• Dental extractions prior to radiotherapy to the jaws for reducing post‐radiotherapy dental complications 2013 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Pre-radiotherapy extraction of diseased molar teeth vs Conservative treatment (restoration of the teeth and leaving them in place during radiotherapy, with oral health education and disease prevention: oral hygiene, fluoride, diet advice)

The review found no eligible studies for this question.

• Dental extractions prior to radiotherapy to the jaws for reducing post‐radiotherapy dental complications 2013 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Pre-radiotherapy extraction of healthy molar teeth vs Conservative treatment (leaving the teeth in place during radiotherapy, with oral health education and disease prevention: oral hygiene, fluoride, diet advice)

The review found no eligible studies for this question.

• Dental extractions prior to radiotherapy to the jaws for reducing post‐radiotherapy dental complications 2013 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Pre-radiotherapy extraction of diseased molar teeth vs Conservative treatment (restoration of the teeth and leaving them in place during radiotherapy, with oral health education and disease prevention: oral hygiene, fluoride, diet advice)

The review found no eligible studies for this question.

• Dental extractions prior to radiotherapy to the jaws for reducing post‐radiotherapy dental complications 2013 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Pre-radiotherapy extraction of diseased molar teeth vs Conservative treatment (restoration of the teeth and leaving them in place during radiotherapy, with oral health education and disease prevention: oral hygiene, fluoride, diet advice)

The review found no eligible studies for this question.

• Dental extractions prior to radiotherapy to the jaws for reducing post‐radiotherapy dental complications 2013 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Pre-radiotherapy extraction of healthy molar teeth vs Conservative treatment (leaving the teeth in place during radiotherapy, with oral health education and disease prevention: oral hygiene, fluoride, diet advice)

The review found no eligible studies for this question.

• Dental extractions prior to radiotherapy to the jaws for reducing post‐radiotherapy dental complications 2013 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Pre-radiotherapy extraction of healthy molar teeth vs Conservative treatment (leaving the teeth in place during radiotherapy, with oral health education and disease prevention: oral hygiene, fluoride, diet advice)

The review found no eligible studies for this question.

• Dental extractions prior to radiotherapy to the jaws for reducing post‐radiotherapy dental complications 2013 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Electronic cigarette use vs Non-smokers (non-users)

E-cigarette use is associated with more cariogenic bacteria and increased dental caries risk compared with non-smokers (narrative synthesis; ungraded).

• An Umbrella Review of E-Cigarettes' Impact on Oral Microbiota and Biofilm Buildup. 2025 All outcomes

  Oral health / dental care (community and clinical samples)
  Narrative synthesis: e-cigarette use linked to increased cariogenic bacteria (S. mutans, Lactobacilli) and worsening dental caries, with flavored e-liquids noted as a caries risk factor (Zieba, Camoni, Yang…
  3 studies
  GRADE not reported

Electronic cigarette use vs Non-smokers (non-users)

E-cigarette use is associated with self-reported gingivitis compared with non-smokers (single included review; ungraded).

• An Umbrella Review of E-Cigarettes' Impact on Oral Microbiota and Biofilm Buildup. 2025 All outcomes

  Oral health / dental care (community and clinical samples)
  Narrative synthesis: a meta-analysis within Camoni et al. combining 6 primary studies found an association between e-cigarette use and self-reported gingivitis, with high heterogeneity (Camoni [28]); the umbrella…
  1 study
  GRADE not reported

Electronic cigarette use vs Traditional (conventional) cigarette smokers

E-cigarette users tend to have a lower plaque index and less periodontal harm than traditional cigarette smokers, although still worse than non-smokers (narrative synthesis; ungraded).

• An Umbrella Review of E-Cigarettes' Impact on Oral Microbiota and Biofilm Buildup. 2025 All outcomes

  Oral health / dental care
  Narrative synthesis: plaque accumulation and periodontal harm were less pronounced in e-cigarette users than in traditional cigarette smokers; cigarette smokers had a significantly higher plaque index than e-cigarette…
  4 studies
  GRADE not reported

Electronic cigarette use vs Non-smokers (non-users)

E-cigarette users appear more likely to develop periodontal disease and worse periodontal parameters than non-smokers (narrative synthesis; ungraded).

• An Umbrella Review of E-Cigarettes' Impact on Oral Microbiota and Biofilm Buildup. 2025 All outcomes

  Oral health / dental care (community and clinical samples)
  Narrative synthesis: e-cigarette use associated with increased risk of periodontal and gingival disease and worse periodontal parameters vs non-smokers (Tattar, Shabil, Figueredo, Yang [23,24,30,31]); no pooled…
  7 studies
  GRADE not reported

Antioxidants (lycopene, curcumin, Oxitard) vs Placebo or no active treatment

The review found no eligible studies for this question.

• Interventions for managing oral submucous fibrosis 2024 · Cochrane All outcomes
  The trials did not measure hospital admission.
  0 studies
  No studies found