evidencegaps
Findings

What do systematic reviews say?

Refine by population, intervention, comparison or outcome
More filters
Evidence found and GRADE certainty

275 questions · 608 findings · 35 reviews

Sort:Best matchNewestHighest certaintyDownload CSV
No studies found 1 · 0.2%GRADE not reported 590 · 97%Very low 0 · 0%Low 5 · 0.8%Moderate 5 · 0.8%High 7 · 1.2%

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Lumbar spine bone mineral density (BMD) · general population

Spine BMD showed an inverted U-shaped association with fluoride (peak ~0.6 mg/L); excluding high risk-of-bias studies gave small positive MDs (e.g., 0.05 g/cm2, 95% CI 0.01-0.10, up to 2.27 mg/L); ungraded.

4 findings from 1 review
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Sensitivity (excluding high risk-of-bias studies): 1.27 to 2.27 mg/L vs null
    MD 0.05 [0.01, 0.10]
    Studies not reported
    GRADE not reported
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Sensitivity (excluding high risk-of-bias studies): 0.60 mg/L vs null
    MD 0.06 [-0.02, 0.13]
    Studies not reported
    GRADE not reported
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Both sexes, main dose-response
    Inverted U-shaped association in both males and females, highest value around 0.6 mg/L (no numeric MD reported in text for main analysis)
    Studies not reported
    GRADE not reported
Show 1 more finding
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Sensitivity (excluding high risk-of-bias studies): above 2.27 mg/L vs null
    MD 0.04 [-0.21, 0.30]
    Studies not reported
    GRADE not reported

Sugar consumption (higher sugar intake) vs No sugar consumption (lower/no intake)

Early childhood caries (ECC) · Preschool children (<6 years)

Higher sugar consumption is associated with early childhood caries in children under 6 years: pooled OR 1.59 (95% CI 1.50 to 1.68) from 9 cohort studies with no heterogeneity (I2=0%); the body of evidence was not GRADE-rated (ungraded).

1 finding from 1 review

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Risk of fragility fractures · Females (all ages)

In females, fragility-fracture risk was U-shaped: lowest ~0.4 mg/L, rising above 0.9 mg/L (RR 0.84 at 0.34, 1.00 at 0.9, 1.13 at 1.1 mg/L vs null); ungraded.

3 findings from 1 review
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Females: drinking-water fluoride 1.1 mg/L vs null
    RR 1.13 [0.93, 1.37]
    Studies not reported
    GRADE not reported
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Females: drinking-water fluoride 0.34 mg/L vs null
    RR 0.84 [0.67, 1.07]
    Studies not reported
    GRADE not reported
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Females: drinking-water fluoride 0.9 mg/L vs null
    RR 1.00 [0.79, 1.27]
    Studies not reported
    GRADE not reported

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Lumbar spine bone mineral density (BMD) · Females (all ages)

In females (low-to-moderate risk-of-bias studies), spine BMD rose then plateaued ~0.5 mg/L: MD 0.02 g/cm2 (95% CI -0.02-0.07) at 0.20 mg/L and 0.06 (-0.01-0.12) across 0.7-2.35 mg/L vs null; ungraded.

2 findings from 1 review
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Females, low-to-moderate risk-of-bias studies: 0.7-2.35 mg/L vs null
    MD 0.06 [-0.01, 0.12]
    Studies not reported
    GRADE not reported
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Females, low-to-moderate risk-of-bias studies: 0.20 mg/L vs null
    MD 0.02 [-0.02, 0.07]
    Studies not reported
    GRADE not reported

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Risk of fragility fractures · Females aged over 50 years

In females over 50, fragility-fracture risk rose steeply from ~0.5 mg/L: RR 0.98 at 0.25, 1.00 at 0.45, and 1.26 (95% CI 1.10-1.46) at 1.0 mg/L drinking-water fluoride vs null; ungraded.

3 findings from 1 review
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Females over 50 years: drinking-water fluoride 0.45 mg/L vs null
    RR 1.00 [0.80, 1.24]
    Studies not reported
    GRADE not reported
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Females over 50 years: drinking-water fluoride 0.25 mg/L vs null
    RR 0.98 [0.83, 1.14]
    Studies not reported
    GRADE not reported
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Females over 50 years: drinking-water fluoride 1.0 mg/L vs null
    RR 1.26 [1.10, 1.46]
    Studies not reported
    GRADE not reported

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Hip/femoral bone mineral density (BMD) · general population

Hip BMD increased with fluoride in both sexes (linearly in males, non-linearly above ~1.2 mg/L in females); no numeric MD reported in text for the main analysis; ungraded.

1 finding from 1 review
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Both sexes, main dose-response
    Hip BMD increased in both sexes, linearly in males and non-linearly (starting above 1.2 mg/L) in females (no numeric MD reported in text for main analysis)
    Studies not reported
    GRADE not reported

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Hip/femoral bone mineral density (BMD) · Females (all ages)

In females (low-to-moderate risk-of-bias studies), hip BMD rose monotonically above ~0.9 mg/L: MD 0.04 g/cm2 (95% CI -0.03-0.12) up to ~2.3 mg/L and 0.09 (-0.09-0.27) at 4.0 mg/L vs null; ungraded.

2 findings from 1 review
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Females, low-to-moderate risk-of-bias studies: up to ~2.3 mg/L vs null
    MD 0.04 [-0.03, 0.12]
    Studies not reported
    GRADE not reported
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Females, low-to-moderate risk-of-bias studies: 4.0 mg/L vs null
    MD 0.09 [-0.09, 0.27]
    Studies not reported
    GRADE not reported

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Wrist fractures · general population

Wrist-fracture risk declined nearly linearly with increasing fluoride: RR 1.00 at 0.01 mg/L to 0.84 at 1.5 mg/L drinking-water fluoride vs null; ungraded.

2 findings from 1 review
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Drinking-water fluoride 1.5 mg/L vs null
    RR 0.84 [0.43, 1.65]
    Studies not reported
    GRADE not reported
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Drinking-water fluoride 0.01 mg/L vs null
    RR 1.00 [0.99, 1.01]
    Studies not reported
    GRADE not reported

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Hip Fracture · general population

Overall hip-fracture risk showed little association with drinking-water fluoride and a nearly flat dose-response curve (narrow CI); no numeric RR reported in text; ungraded.

1 finding from 1 review
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Overall dose-response (0 to highest exposure)
    Curve indicated little association and was nearly flat, with a comparatively narrow 95% confidence band (no numeric RR reported in text)
    Studies not reported
    GRADE not reported

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Lumbar spine bone mineral density (BMD) · Females aged over 50 years

In females over 50, spine BMD showed an inverted U-shaped curve with a downward trend beginning at lower fluoride concentrations than in the overall analysis; no numeric MD reported in text; ungraded.

1 finding from 1 review
  • The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. 2025 All outcomes
    Long-term / lifetime fluoride exposure · General population; 37 observational studies (1944-2024), predominantly North America (USA, Canada) and Northern Europe (Finland, Sweden), plus UK, Poland, Italy, Germany, China, Taiwan, South Korea, Ethiopia; exposure mainly community drinking-water fluoride · Females >50, spine BMD dose-response
    Inverted U-shaped curve with a downward trend starting at lower fluoride concentrations than the overall analysis (no numeric MD reported in text)
    Studies not reported
    GRADE not reported

Highest BMI category (overweight/obese) vs Lowest BMI category (normal weight/underweight)

Early childhood caries (ECC) · Children (approx. 4-18 years)

In the Region: Asian countries subgroup, the BMI (highest vs lowest)-childhood caries association was significant (OR 1.70, 95% CI 1.25 to 2.32; ungraded).

17 findings from 1 review
Show 14 more findings

ART sealant using high-viscosity glass ionomer (press-finger technique) vs No comparator

Caries-free sealed pits and fissures · Permanent teeth with sealed pits and fissures

The pooled caries-free rate was 85% at 6 years.

6 findings from 1 review
Show 3 more findings

ART sealant using high-viscosity glass ionomer (press-finger technique) vs No comparator

Retention of sealant (complete or partial retention) · Permanent teeth

The pooled retention rate was 75% at 1 year.

5 findings from 1 review
Show 2 more findings

Higher family income / socioeconomic status vs Lower income / worse socioeconomic status

Oral health-related quality of life · Adolescents (10-19 years)

Higher family income / better socioeconomic status is associated with better OHRQoL in adolescents (narrative synthesis; no pooled estimate or GRADE rating).

1 finding from 1 review
  • Oral-health-related quality of life in adolescents: umbrella review. 2023 All outcomes
    Community/school/clinic settings; adolescents 10-19 years; included reviews conducted in multiple countries
    Adolescents from families with higher incomes and higher levels of maternal education have better OHRQoL scores [34]. Worse oral health status, older age, female sex and worse socioeconomic status were significantly…
    Studies not reported
    GRADE not reported

Higher circulating 1,25-dihydroxyvitamin D (1,25(OH)2D) concentration vs Lower circulating 1,25-dihydroxyvitamin D (1,25(OH)2D) concentration

Prostate cancer · Participants in observational studies

The meta-analysis of observational studies reported a OR of 0.99 (95% CI 0.87 to 1.12) for higher versus lower circulating vitamin D concentration.

1 finding from 1 review

Higher circulating 1,25-dihydroxyvitamin D (1,25(OH)2D) concentration vs Lower circulating 1,25-dihydroxyvitamin D (1,25(OH)2D) concentration

Breast cancer · Participants in observational studies

The meta-analysis of observational studies reported a OR of 0.99 (95% CI 0.68 to 1.47) for higher versus lower circulating vitamin D concentration.

1 finding from 1 review

Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)

Spine bone mineral density · Females (all ages)

Among females in low-to-moderate-risk-of-bias studies, the reported spine-BMD estimate above 2.35 mg/L water fluoride was MD 0.07 g/cm2 (95% CI 0.11 to 0.24; ungraded).

2 findings from 1 review

Higher BMI (continuous / per-unit increment) vs Lower BMI (continuous reference / per 1 kg/m2 decrement)

Dental caries in children · Children (approx. 4-18 years)

Pooling studies that used BMI as a continuous variable showed no significant association between per-unit BMI and childhood dental caries (OR 1.01, 95% CI 0.99 to 1.03; I2=3.5%); ungraded.

3 findings from 1 review

High-viscosity glass-ionomer ART restorations vs No comparator

Restoration survival · Permanent posterior teeth with single-surface cavities

The pooled survival rate was 93% at 2 years.

6 findings from 1 review
Show 3 more findings

High-viscosity glass-ionomer ART restorations vs No comparator

Restoration survival · Permanent posterior teeth with multiple-surface cavities

The pooled survival rate was 41% at 2 years.

3 findings from 1 review