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Each row is one question a systematic review asked: who, what, compared with what, and which outcome, with the effect it found and how certain that is. Words match anywhere in the field.

Limit to evidence status or GRADE (optional)

75,239 questions in 5,342 reviews

current versions
No studies 15,213 · 20.2%Ungraded 10,323 · 13.7%Very low 17,528 · 23.3%Low 17,951 · 23.9%Moderate 11,190 · 14.9%High 3,034 · 4%

Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.

QuestionEffectEvidenceStatus / GRADE
Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)
Risk of fragility fractures · Females aged over 50 years · Long-term / lifetime fluoride exposure, Females over 50 years: drinking-water fluoride 1.0 mg/L vs null
The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. (2025)
RR 1.26 [1.10, 1.46]NRUngraded
Intervention NR
Postoperative hypersensitivity · TheraCal LC vs Dycal (Bayoumy et al.)
Efficacy of different cavity liners compared to no cavity lining in managing deep caries in vital permanent… (2025)
Patients pain-free at 12 months 100% (TheraCal) vs 81% (Dycal); p<0.051 studyUngraded
Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)
Lumbar spine bone mineral density (BMD) · General population (both sexes, all ages) · Long-term / lifetime fluoride exposure, Sensitivity (excluding high risk-of-bias studies): above 2.27 mg/L vs null
The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. (2025)
MD 0.04 [-0.21, 0.30]NRUngraded
Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)
Risk of wrist fractures · General population (both sexes, all ages) · Long-term / lifetime fluoride exposure, Drinking-water fluoride 1.5 mg/L vs null
The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. (2025)
RR 0.84 [0.43, 1.65]NRUngraded
Higher per-capita expenditure on dental health care vs Lower per-capita expenditure on dental health care (USD bands: $0-50 / $51-100 / >$100)
Caries experience (mean DMFT) · 12-year-old children across European countries (national/regional epidemiological surveys, 2011-2022) · Cross-sectional (survey data 2011-2022), $51-100 per capita
Caries status in 12-year-old children, geographical location and socioeconomic conditions across European… (2025)
MEAN 2.14 [1.40, 2.89]6 studiesUngraded
Genetically predicted periodontitis vs Lower genetically predicted periodontitis liability
Forearm fracture · European GWAS participants · SVMR MR-Egger
From teeth to bone: dental caries has causal effects on osteoporosis and osteoporotic fracture. (2025)
OR 0.994 [0.948, 1.042]490889 participantsUngraded
Late tooth brushing initiation (>=12 months, or >=2 years in some studies) vs Early tooth brushing initiation (<12 months, or <2 years)
Early childhood caries (presence/prevalence/severity by dmft/dmfs) · Healthy children under 6 years of age (6 months to 6 years); preschool children · Primary analysis (all 10 studies)
Optimal tooth brushing initiation age and frequency for preventing early childhood caries: a systematic… (2025)
OR 1.40 [0.91, 2.16]10 studies · 23200 participantsUngraded
Intervention NR
Composite: Preference for replacement over repair - Scenario 3: secondary caries · Coverage: Not covering
Clinical Decision-Making of Repair vs. Replacement of Defective Direct Dental Restorations: A Multinational… (2025)
RR 2.53 [1.70, 3.78]NRUngraded
Partial pulpotomy vs Full (complete) pulpotomy
Pulp sensibility (EPT/cold response) · Mature permanent (molar) teeth with deep caries and symptoms indicative of irreversible pulpitis (spontaneous pain) · 1 year
The effectiveness of partial pulpotomy compared with full pulpotomy in managing deep caries in vital… (2025)
Jassal: positive pulp sensibility at 1 year - EPT positive in PP 95.45% (21/22) vs FP 63.6% (14/22); cold test positive in PP 45.45% (10/22) vs FP 13.63% (3/22). Sensibility was not used to ascertain the success…1 study · 44 participantsUngraded
Not applicable (single-group prevalence) vs Not applicable (single-group prevalence)
Early childhood caries (ECC), prevalence · Children aged 0-5 years in North Africa · Country: Egypt
Prevalence and risk factors for early childhood caries in North Africa: a systematic review and meta-analysis. (2025)
Prevalence 62 [53, 70]10 studiesUngraded
Intervention NR
Specificity · Imaging modality: Intraoral photographic images
Examining the diagnostic accuracy of artificial intelligence for detecting dental caries across a range of… (2025)
Specificity 0.84 [0.77, 0.91]7 studiesUngraded
Not applicable (single-group prevalence) vs Not applicable (single-group prevalence)
Early childhood caries (ECC), prevalence · Children aged 0-5 years in North Africa · Overall (all included studies)
Prevalence and risk factors for early childhood caries in North Africa: a systematic review and meta-analysis. (2025)
Prevalence 57 [50, 64]18 studies · 11319 participantsUngraded
Intervention NR
Amalgam: Preference for replacement over repair - Scenario 6: corrosion · Continent: Europe
Clinical Decision-Making of Repair vs. Replacement of Defective Direct Dental Restorations: A Multinational… (2025)
RR 1.28 [0.91, 1.81]6 studiesUngraded
Secondary (passive/secondhand) smoking exposure during childhood vs No secondary smoking exposure
Caries incidence (early childhood caries) · Preschool children aged <=71 months (caries outcome assessed at 3-6 years) · Caries incidence by age 3 years (exposure from infancy, 4-18 months), Overall
Secondary Smoking and Early Childhood Caries: A Systematic Review and Meta-Analysis. (2025)
RR 1.45 [1.41, 1.49]2 studies · 102,830 participantsLow
Obesity or overweight (higher BMI, mostly WHO BMI ≥25/≥30; 2 studies used waist circumference) vs Normal weight (not overweight or obese)
Dental caries (study-defined binary; assessed by DMFT, number of dental caries, or dentist diagnosis) · Adults (≥18 years)
Multimorbidity patterns of dental caries and obesity/overweight among adults: a systematic review and… (2025)
OR 1.06 [0.98, 1.14]18 studies · 270408 participantsUngraded
Feeding on demand vs Scheduled feeding
Early childhood caries (ECC) · Children aged 0-5 years in North Africa
Prevalence and risk factors for early childhood caries in North Africa: a systematic review and meta-analysis. (2025)
OR 9.66 [4.26, 21.93]1 studyUngraded
Country-level income inequality (Gini index) vs Lower vs higher income inequality categories
Oral health-related quality of life (OHRQoL sum score, transformed 0-100) · Community-dwelling elderly persons aged ≥60 years · Adequate equality
Association between oral health-related quality of life and structural determinants of health among elderly… (2025)
MEAN 75.4 [70.1, 82.7]NRUngraded
Intervention NR
Sensitivity · Imaging modality: Panoramic radiographs
Examining the diagnostic accuracy of artificial intelligence for detecting dental caries across a range of… (2025)
Sensitivity 0.83 [0.72, 0.94]8 studiesUngraded
Intervention NR
Plaque index, e-cigarette users versus non-smokers: no significant difference (contrary/null finding) · Ralho (6 of 8 studies); Thiem (1 study)
An Umbrella Review of E-Cigarettes' Impact on Oral Microbiota and Biofilm Buildup. (2025)
Qualitative (narrative synthesis) No significant plaque-index difference vs non-smokers2 studiesUngraded
Genetically predicted periodontitis vs Lower genetically predicted periodontitis liability
Femur fracture · European GWAS participants · SVMR MR-Egger
From teeth to bone: dental caries has causal effects on osteoporosis and osteoporotic fracture. (2025)
OR 1.063 [0.991, 1.140]489106 participantsUngraded
Intervention NR
Composite: Preference for replacement over repair - Scenario 4: marginal discoloration · HDI: Very high
Clinical Decision-Making of Repair vs. Replacement of Defective Direct Dental Restorations: A Multinational… (2025)
RR 1.82 [1.34, 2.46]10 studiesUngraded
Orofacial cleft (cleft lip and/or palate) as exposure vs Healthy controls without cleft
Bleeding Index (BI) · Individuals assessed for periodontal health (mainly children and adolescents, age >2 years)
Oral health in patients with cleft lip and palate: a systematic literature review and meta-analysis of… (2025)
the bleeding index (BI) showed significantly higher values for subjects with cleft lip and/or palate (BI p < 0.0001)NRUngraded
Orofacial cleft (cleft lip and/or palate) as exposure vs Healthy controls without cleft
Oral microbiota composition · Individuals assessed for oral microbiota (mainly children and adolescents)
Oral health in patients with cleft lip and palate: a systematic literature review and meta-analysis of… (2025)
no estimate extracted8 studiesUngraded
Microinvasive techniques (resin infiltration, sealant, glass ionomer) vs Invasive treatment (conventional restorations)
Radiographic progression of proximal caries lesions · Children and adults with non-cavitated proximal (interproximal) caries lesions in primary and/or permanent teeth (ages…
Microinvasive interventions in the management of proximal caries lesions in primary and permanent teeth-… (2025)
no estimate extracted0 studiesNo studies
Male sex vs Female sex
Early childhood caries (ECC) · Children aged 0-5 years in North Africa
Prevalence and risk factors for early childhood caries in North Africa: a systematic review and meta-analysis. (2025)
OR 2.911 [1.42, 5.99]1 studyUngraded
Replacement of the defective restoration vs Repair of the defective restoration
Amalgam: Preference for replacement over repair - Scenario 1: partial loss or fracture of the restoration · Dentists managing a defective direct amalgam restoration (posterior occlusal Class I; standardized vignette of a… · Not applicable (single time-point survey, June to October 2023), Overall (all 21 countries pooled)
Clinical Decision-Making of Repair vs. Replacement of Defective Direct Dental Restorations: A Multinational… (2025)
RR 3.94 [2.93, 5.31]21 studies · 3680 participantsUngraded
Late tooth brushing initiation (>=12 months, or >=2 years in some studies) vs Early tooth brushing initiation (<12 months, or <2 years)
Early childhood caries (presence/prevalence/severity by dmft/dmfs) · Healthy children under 6 years of age (6 months to 6 years); preschool children · Leave-one-out sensitivity analysis (Wagner 2017 outlier excluded, k=9)
Optimal tooth brushing initiation age and frequency for preventing early childhood caries: a systematic… (2025)
OR 1.75 [1.50, 2.03]9 studiesUngraded
Hall technique vs Sodium fluoride varnish (NaF)
Treatment success (caries lesion arrest or restoration survival) · Children (aged 3-11 y) with cavitated caries lesions in primary teeth · 6 months, 6-month follow-up
Comparative success of minimally invasive treatments for cavitated caries in primary teeth: a network… (2025)
OR 8.19 [1.44, 46.63]44 studiesModerate
Genetically predicted periodontitis vs Reference (lower genetically predicted periodontitis liability)
Postmenopausal osteoporosis with pathological fracture · Postmenopausal women (European ancestry) · Lifelong genetic liability, SVMR (IVW), total causal effect
From teeth to bone: dental caries has causal effects on osteoporosis and osteoporotic fracture. (2025)
OR 1.014 [0.857, 1.199]281786 participantsUngraded
Higher drinking-water fluoride exposure vs Null / lowest drinking-water fluoride exposure (reference)
Risk of hip fractures · General population (both sexes, all ages) · Long-term / lifetime fluoride exposure, Overall dose-response (0 to highest exposure)
The association of fluoride exposure with bone density and fracture risk: a dose-response meta-analysis. (2025)
Curve indicated little association and was nearly flat, with a comparatively narrow 95% confidence band (no numeric RR reported in text)NRUngraded
Intervention NR
Composite: Preference for replacement over repair - Scenario 7: non-stable (mobile) restoration · Continent: Asia
Clinical Decision-Making of Repair vs. Replacement of Defective Direct Dental Restorations: A Multinational… (2025)
RR 8.67 [5.32, 14.13]11 studiesUngraded
Epilepsy (exposure) vs Healthy participants
dmft index (primary teeth) · Children or adolescents with epilepsy · Children or adolescents
Evaluating the DMFT and dmft indices in people with epilepsy: A systematic review and meta-analysis. (2025)
SMD 0.132 [-0.220, 0.484]NRUngraded
Hydraulic calcium silicate cements (HCSC; MTA or Biodentine) vs Calcium hydroxide (CaOH)
Clinical and radiographic success · Vital permanent teeth (mature or immature) with deep or extremely deep caries and asymptomatic pulp or reversible… · >=12 months
Effectiveness of calcium hydroxide compared to hydraulic calcium silicate cements for direct pulp capping in… (2025)
OR 2.68 [1.7, 4.22]5 studies · 552 participantsModerate
Intervention NR
Composite: Preference for replacement over repair - Scenario 3: secondary caries · Coverage: Covering cost of minimally invasive treatment
Clinical Decision-Making of Repair vs. Replacement of Defective Direct Dental Restorations: A Multinational… (2025)
RR 2.28 [1.69, 3.08]NRUngraded
Intervention NR
Amalgam: Preference for replacement over repair - Scenario 5: open margin · HDI: High
Clinical Decision-Making of Repair vs. Replacement of Defective Direct Dental Restorations: A Multinational… (2025)
RR 6.16 [5.32, 7.14]7 studiesUngraded
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
Incidence of proximal (interdental) caries lesions from bitewing radiographs · Children, adolescents and adults undergoing fixed (multi-bracket) orthodontic treatment · At debonding (~23-24 months)
Fluoride mouthrinses for prevention of initial caries in orthodontic patients - a systematic review and… (2025)
In one study assessments of proximal caries incidence were made as well [18]. However, just the data on the incidence of white spot lesions was included in our meta-analysis as different endpoints for the assessments…1 studyUngraded
Lacunar stroke (cases) vs Without lacunar stroke (controls)
Periodontal inflamed surface area (PISA) · Adults
The contribution of oral infectious diseases in lacunar stroke based on meta-analysis and Mendelian… (2025)
MD 849.92 [698.86, 1000.98]2 studiesUngraded
Intervention NR
Amalgam: Preference for replacement over repair - Scenario 4: marginal discoloration · Continent: Europe
Clinical Decision-Making of Repair vs. Replacement of Defective Direct Dental Restorations: A Multinational… (2025)
RR 6.88 [4.77, 9.92]6 studiesUngraded
Postbiotics from Lactobacillus spp. (cell-free supernatants, biosurfactants, lipoteichoic acid, bacterial lysates) vs Untreated control
Reduced enamel demineralization · Cariogenic bacteria (mainly Streptococcus mutans reference strains) and oral biofilms in vitro · Exposure 24 h to 7 days
Postbiotics and Dental Caries: A Systematic Review. (2025)
One in vitro multispecies-biofilm study reported that a postbiotic (L. reuteri cell-free supernatant) reduced enamel demineralization, indicating a protective effect against caries; no pooled estimate.1 studyUngraded
Children with dental caries vs Children without dental caries (caries-free)
Serum ferritin level · Children and adolescents (0-18 years; most included reviews focused on <6 years)
Association Between Iron Deficiency Anemia and Dental Caries in Children: A Systematic Umbrella Meta-Analysis. (2025)
MD -3.96 [-8.48, 0.57]4 studiesVery low
Intervention NR
Composite: Preference for replacement over repair - Scenario 4: marginal discoloration · Continent: South America
Clinical Decision-Making of Repair vs. Replacement of Defective Direct Dental Restorations: A Multinational… (2025)
RR 1.44 [0.71, 2.91]2 studiesUngraded
Hydroxyapatite (e.g., nano-HAp) vs Mesoporous silica (SiO2)
Immediate (24 h) resin-dentin bond strength (MPa) · Artificial caries-affected dentin (ACAD) in extracted permanent human teeth (in vitro) · 24 h (immediate), Self-Etch + chemical ACAD
Biomimetic Remineralization Strategies for Dentin Bond Stability-Systematic Review and Network Meta-Analysis. (2025)
MD -3.756 [-10.536, 3.024]0 studiesModerate
Genetically predicted periodontitis vs Lower genetically predicted periodontitis liability, adjusted for DMFS
Osteoporosis · European GWAS participants · MVMR MR-Egger
From teeth to bone: dental caries has causal effects on osteoporosis and osteoporotic fracture. (2025)
OR 1.005 [0.940, 1.074]483725 participantsUngraded
Genetically predicted dental caries (DMFS index) vs Reference (1-SD lower genetically predicted DMFS)
Fracture of femur · European-ancestry adults · Lifelong genetic liability, MVMR (IVW), adjusted for periodontitis
From teeth to bone: dental caries has causal effects on osteoporosis and osteoporotic fracture. (2025)
OR 1.069 [0.923, 1.239]489106 participantsUngraded
Flavonoids (e.g., quercetin, proanthocyanidin) vs No biomimetic remineralization (control)
Immediate (24 h) resin-dentin bond strength (MPa) · Artificial caries-affected dentin (ACAD) in extracted permanent human teeth (in vitro) · 24 h (immediate), Self-Etch + chemical ACAD
Biomimetic Remineralization Strategies for Dentin Bond Stability-Systematic Review and Network Meta-Analysis. (2025)
MD 4.604 [-2.011, 11.219]1 studyModerate
Out-of-pocket health expenditure vs Lower vs higher out-of-pocket expenditure categories
Oral health-related quality of life (OHRQoL sum score, transformed 0-100) · Community-dwelling elderly persons aged ≥60 years · Highest out-of-pocket expenditure
Association between oral health-related quality of life and structural determinants of health among elderly… (2025)
MEAN 67.5 [58.5, 76.5]NRUngraded
Intervention NR
Amalgam: Preference for replacement over repair - Scenario 8: disruption of occlusal integrity · Continent: South America
Clinical Decision-Making of Repair vs. Replacement of Defective Direct Dental Restorations: A Multinational… (2025)
RR 2.12 [0.66, 6.82]2 studiesUngraded
Genetically predicted DMFS (dental caries) vs Lower genetically predicted DMFS, adjusted for periodontitis
Lumbar spine and pelvis fracture · European GWAS participants · MVMR MR-Egger
From teeth to bone: dental caries has causal effects on osteoporosis and osteoporotic fracture. (2025)
OR 1.034 [0.769, 1.390]490700 participantsUngraded
Prior history of dental visit vs No prior dental visit
Early childhood caries (ECC) · Children aged 0-5 years in North Africa
Prevalence and risk factors for early childhood caries in North Africa: a systematic review and meta-analysis. (2025)
OR 2.444 [1.108, 2.072]1 studyUngraded
Lactobacillus-derived postbiotics vs Not specified
Virulence-gene expression related to adhesion acid production and exopolysaccharide synthesis · Reference strains of Streptococcus mutans and cariogenic biofilms · 24 h to 7 days
Postbiotics and Dental Caries: A Systematic Review. (2025)
no estimate extracted7 studiesUngraded