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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)

5,762 questions in 263 reviews · Dental caries

current versions
No studies 321 · 5.6%Ungraded 4,450 · 77.2%Very low 455 · 7.9%Low 297 · 5.2%Moderate 200 · 3.5%High 39 · 0.7%

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
Preformed metal crown (fitted using the Hall Technique) vs Preformed metal crown (fitted using a conventional technique)
Outcome NR · Children with decayed primary molar teeth
Preformed crowns for decayed primary molar teeth (2015) · Cochrane
None of the included studies compared the effectiveness or safety of the Hall Technique versus the conventional technique of fitting a crown. No RCT evidence found.0 studiesNo studies
Chlorhexidine varnish vs Placebo or no treatment
Pain, quality of life, patient satisfaction or costs · Children and adolescents below 18 years at study start (included studies: children from birth to 15 years), with…
Chlorhexidine treatment for the prevention of dental caries in children and adolescents (2015) · Cochrane
No trials reported on pain, quality of life, patient satisfaction or costs.0 studiesNo studies
Fluoride gel (topically applied; operator- or self-applied; any fluoride agent/concentration; frequency at least once a year) vs Placebo or no treatment
Caries increment on permanent whole teeth (D(M)FT), prevented fraction · Children and adolescents aged 16 years or younger (permanent dentition) · Nearest to 3 years, No-treatment-controlled trials
Fluoride gels for preventing dental caries in children and adolescents (2015) · Cochrane
PF 0.43 [0.29, 0.57]6 studiesUngraded
Fluoride gel (topically applied; operator- or self-applied; any fluoride agent/concentration; frequency at least once a year) vs Placebo or no treatment
Caries increment on primary (deciduous) whole teeth (d(m)ft), prevented fraction · Children with primary (deciduous) teeth (mostly preschool children aged under 6 years) · Nearest to 3 years
Fluoride gels for preventing dental caries in children and adolescents (2015) · Cochrane
There were no data on d(m)ft available.0 studiesNo studies
Breastfeeding vs Bottle feeding
Presence of dental caries · Children with exclusively primary dentition (age ≤71 months)
Breast and Bottle Feeding as Risk Factors for Dental Caries: A Systematic Review and Meta-Analysis. (2015)
Four studies showed that bottle fed children had more dental caries (p<0.05), while three studies found no such association (p>0.05); the review concluded that breastfeeding can protect against dental caries in early…7 studiesUngraded
Resin infiltration vs Fluoride varnish, sham/placebo, or flossing advice (non-invasive control)
Caries (lesion) progression (radiographic) · Dentate children and adults with non-cavitated proximal caries lesions extending into enamel or dentine (not pulp) in… · 12 to 36 months (radiographic follow-up), Resin infiltration
Micro‐invasive interventions for managing proximal dental decay in primary and permanent teeth (2015) · Cochrane
OR 0.19 [0.08, 0.46]2 studiesUngraded
Cessation of water fluoridation (fluoride removed from the water supply) vs Continued fluoridated water
Disparities in caries across socioeconomic status (SES) · People of all ages in a previously fluoridated community (Maupome 2001: children with generally low caries experience)
Water fluoridation for the prevention of dental caries (2015) · Cochrane
No evidence to determine the effect of the cessation of water fluoridation on disparities in caries across SES.0 studiesNo studies
Fluoridated milk vs Non-fluoridated milk
Caries in primary teeth: dmft (3 years) · General population, irrespective of age or level of risk for dental caries · 3 years
Fluoridated milk for preventing dental caries (2015) · Cochrane
MD -1.14 [-1.86, -0.42]1 study · 166 participantsLow
Preformed metal crown (fitted using the Hall Technique) vs Non-restorative caries treatment
Adverse events: gingival bleeding · Children with decayed primary molar teeth · Long term (12 months)
Preformed crowns for decayed primary molar teeth (2015) · Cochrane
RR 1.09 [0.42, 2.86]1 study · 92 participantsVery low
Preformed crown (any material; conventional technique or Hall Technique) vs Filling (any material; with or without complete carious tissue excavation; with or without pulp treatment)
Pain · Children with decayed primary molar teeth · Short term (less than 12 months)
Preformed crowns for decayed primary molar teeth (2015) · Cochrane
Short term (less than 12 months): effect not estimable (Analysis 1.2.1; 64 teeth, 32 participants; one study, Hutcheson 2012).1 study · 64 participantsUngraded
Preformed metal crown (stainless steel), conventional technique vs Aesthetic crown (stainless steel with composite/white veneer), conventional technique
Adverse events: bone resorption · Children with decayed primary molar teeth · Six months and four years
Preformed crowns for decayed primary molar teeth (2015) · Cochrane
Bone resorption: one case at six months in a tooth treated with a veneer crown; no bone resorption at either the veneer crown or stainless steel sites at four-year follow-up (Analysis 3.2).1 study · 11 participantsVery low
Fluoride gel (topically applied; operator- or self-applied; any fluoride agent/concentration; frequency at least once a year) vs Placebo or no treatment
Unacceptability of treatment (dropouts/exclusions during the trial) · Children and adolescents aged 16 years or younger · During trial, Placebo-controlled trials
Fluoride gels for preventing dental caries in children and adolescents (2015) · Cochrane
RR 1.05 [0.91, 1.22]11 studies · 6067 participantsUngraded
Cessation of water fluoridation (fluoride removed from the water supply) vs Continued fluoridated water
Adverse effects · People of all ages in a previously fluoridated community (Maupome 2001: children with generally low caries experience)
Water fluoridation for the prevention of dental caries (2015) · Cochrane
No evidence to determine whether cessation of a water fluoridation programme is associated with any harms.0 studiesNo studies
Preformed metal crown (stainless steel), conventional technique vs Aesthetic crown (stainless steel with composite/white veneer), conventional technique
Adverse events: gingival bleeding · Children with decayed primary molar teeth · Six months and four years
Preformed crowns for decayed primary molar teeth (2015) · Cochrane
At six months, none (0/11) of the PMC sites had gingival bleeding, but all (11/11) veneer sites had bleeding, 10 of which bled on probing; statistically significant (McNemar's test, P < 0.001). At four years, one case…1 study · 11 participantsVery low
Initiation of water fluoridation (artificial or natural) vs Low/non-fluoridated water (0.4 ppm fluoride or less)
Caries in deciduous teeth (change in dmft) · People of all ages in a community setting; the included caries studies were all in children aged 3 to 16 years · Follow-up 3 to 12 years
Water fluoridation for the prevention of dental caries (2015) · Cochrane
MD -1.81 [-2.31, -1.31]9 studies · 44268 participantsLow
Xylitol chewing gum vs No treatment or non-cariogenic control
Outcome NR · Children and adults · At least 1 year
Xylitol‐containing products for preventing dental caries in children and adults (2015) · Cochrane
It was surprising that there were no eligible randomised trials testing xylitol chewing gums against either no treatment or a non-cariogenic control.0 studiesNo studies
Chlorhexidine chewing gum vs Placebo or no intervention (including routine care)
Outcome NR · Children and adolescents below 18 years at study start (included studies: children from birth to 15 years), with…
Chlorhexidine treatment for the prevention of dental caries in children and adolescents (2015) · Cochrane
There were no trials on other products containing chlorhexidine such as sprays, toothpastes, chewing gums or mouthrinses.0 studiesNo studies
Initiation of water fluoridation (artificial or natural) vs Low/non-fluoridated water (0.4 ppm fluoride or less)
Caries in permanent teeth (change in DMFS) · Children aged about 12 to 16 years (Hardwick 1982), community setting · Follow-up (single study, Hardwick 1982)
Water fluoridation for the prevention of dental caries (2015) · Cochrane
MD -2.46 [-3.81, -1.11]1 study · 343 participantsUngraded
Chlorhexidine varnish (10%) vs Placebo or no treatment
Elevated mutans streptococci levels (>=4 with caries screen; high vs low) · Children and adolescents below 18 years at study start (included studies: children from birth to 15 years), with… · 6 to 36 months, permanent dentition
Chlorhexidine treatment for the prevention of dental caries in children and adolescents (2015) · Cochrane
RR 0.93 [0.80, 1.07]1 study · 496 participantsVery low
Micro-invasive treatment (proximal sealing or resin infiltration): resin sealant, glass ionomer sealant, polyurethane/adhesive patch, or resin infiltration vs Non-invasive measures (e.g. fluoride varnish, flossing/oral hygiene advice), no treatment, or placebo
Material deficiency (retention/adaptation loss; re-treatment) · Dentate children and adults with non-cavitated proximal caries lesions extending into enamel or dentine (not pulp) in… · 3 years
Micro‐invasive interventions for managing proximal dental decay in primary and permanent teeth (2015) · Cochrane
One study (Alkilzy 2011, sealant patch) reported material deficiency: 10% total and 23% partial loss of proximal sealants after three years; 53% maintained perfect margins and none had open margins. No studies reported…1 studyUngraded
Chlorhexidine varnish (1%, 10% or 40%) vs Placebo or no treatment
Caries increment in the primary teeth (d(m)fs/t) · Children and adolescents below 18 years at study start (included studies: children from birth to 15 years), with… · 24 months, primary dentition
Chlorhexidine treatment for the prevention of dental caries in children and adolescents (2015) · Cochrane
Two trials with unit of analysis problem. Data imputations indicated no evidence to claim or refute a benefit2 studies · 471 participantsUngraded
Preformed crown (any material; conventional technique or Hall Technique) vs Filling (any material; with or without complete carious tissue excavation; with or without pulp treatment)
Adverse events: gingival bleeding · Children with decayed primary molar teeth · Long term (12 months)
Preformed crowns for decayed primary molar teeth (2015) · Cochrane
RR 1.74 [0.99, 3.06]2 studies · 195 participantsLow
Initiation of water fluoridation (artificial or natural) vs Low/non-fluoridated water (0.4 ppm fluoride or less)
Change in proportion of caries-free children (deciduous teeth) · People of all ages in a community setting; the included caries studies were all in children aged 3 to 16 years · Follow-up 3 to 12 years
Water fluoridation for the prevention of dental caries (2015) · Cochrane
MD 0.15 [0.11, 0.19]10 studies · 39966 participantsLow
Fluoridated milk vs Non-fluoridated milk
Caries in permanent teeth: DMFT (3 years) · General population, irrespective of age or level of risk for dental caries · 3 years
Fluoridated milk for preventing dental caries (2015) · Cochrane
MD -0.13 [-0.24, -0.02]1 study · 166 participantsLow
Xylitol wipes (4.2 g/day) vs Control wipes (no xylitol)
Adverse effects · Infants (primary teeth) · 12 months
Xylitol‐containing products for preventing dental caries in children and adults (2015) · Cochrane
The authors reported that there were no adverse effects for either group. Zhan 2012.1 study · 44 participantsUngraded
Fluoride gel (topically applied; operator- or self-applied; any fluoride agent/concentration; frequency at least once a year) vs Placebo or no treatment
Proportion of children not remaining caries-free · Children and adolescents aged 16 years or younger (permanent dentition) · Permanent dentition
Fluoride gels for preventing dental caries in children and adolescents (2015) · Cochrane
RR 0.72 [0.46, 1.14]1 study · 280 participantsUngraded
Higher circulating 25-hydroxyvitamin D (25(OH)D) concentration vs Lower circulating 25-hydroxyvitamin D (25(OH)D) concentration
Prostate cancer · Adults (general population)
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
OR 1.04 [0.98, 1.09]14 studies · 28988 participantsUngraded
Higher circulating 25OHD concentration vs Lower circulating 25OHD concentration
Alzheimer’s disease · Participants in observational studies
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
SMD (to OR) 0.08 [0.01, 0.63]7 studies · 1005 participantsUngraded
Higher circulating 25OHD concentration vs Lower circulating 25OHD concentration
Aggressive prostate cancer · Participants in observational studies
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
OR 0.98 [0.84, 1.15]6 studies · 4524 participantsUngraded
Vitamin D supplementation vs Placebo or control
Fasting glucose · Adults with diabetes · Diabetes patients with normal glucose tolerance
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
WMD 0.01 [-0.21, 0.23]NRUngraded
Repair of a defective resin composite restoration in a permanent molar or premolar tooth (with resin composite) vs Replacement of a defective resin composite restoration in a permanent molar or premolar tooth (with resin composite)
Presence of clinical symptoms (pain, swelling, diagnosis of pulpitis, abscess formation) · Adults (16 years or over) with one or more defective resin composite restoration(s) in a molar or premolar tooth/teeth · Medium term (less than 5 years) or long term (5 years and above)
Replacement versus repair of defective restorations in adults: resin composite (2014) · Cochrane
No randomised controlled trials were found0 studiesNo studies
Higher circulating 25-hydroxyvitamin D (25(OH)D) concentration vs Lower circulating 25-hydroxyvitamin D (25(OH)D) concentration
Type 2 diabetes · Adults (general population)
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
OR 0.63 [0.56, 0.69]16 studies · 72204 participantsUngraded
Vitamin D compounds (supplementation) vs Placebo or control
Risk of hypercalcaemia · Adults with chronic kidney disease requiring dialysis
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
RR 3.80 [0.90, 16.12]5 studies · 382 participantsUngraded
Vitamin D supplementation vs Placebo or control
Bone mineral density in femoral neck · Older or community-dwelling adults
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
WMD 1.10 [0.40, 1.90]8 studiesUngraded
Vitamin D supplementation vs Placebo or control
Bone mineral density in lumbar spine · Older or community-dwelling adults
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
WMD 0.10 [-0.60, 0.70]7 studiesUngraded
Higher circulating 25-hydroxyvitamin D (25(OH)D) concentration vs Lower circulating 25-hydroxyvitamin D (25(OH)D) concentration
Sporadic colorectal adenoma recurrence · Adults (general population)
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
OR 0.87 [0.57, 1.33]3 studies · 1366 participantsUngraded
Higher circulating 25-hydroxyvitamin D (25(OH)D) concentration vs Lower circulating 25-hydroxyvitamin D (25(OH)D) concentration
Ischaemic heart disease · Adults (general population)
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
HR 0.72 [0.65, 0.81]19 studies · 82982 participantsUngraded
Vitamin D supplementation vs Placebo or control
Fractures: non-vertebral · Older or community-dwelling adults
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
RR 0.79 [0.63, 0.99]5 studies · 7130 participantsUngraded
Higher maternal circulating 25-hydroxyvitamin D (25(OH)D) concentration vs Lower maternal circulating 25-hydroxyvitamin D (25(OH)D) concentration
Small for gestational age · Pregnant women and their offspring
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
OR 0.54 [0.44, 0.67]6 studies · 6851 participantsUngraded
Higher circulating 1,25(OH)2D concentration vs Lower circulating 1,25(OH)2D concentration
Prostate cancer · Participants in observational studies
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
OR 0.99 [0.87, 1.14]7 studies · 3640 participantsUngraded
Higher circulating 25-hydroxyvitamin D (25(OH)D) concentration vs Lower circulating 25-hydroxyvitamin D (25(OH)D) concentration
Breast cancer · Adults (general population) · Premenopausal
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
RR 1.01 [0.97, 1.06]6 studies · 2890 participantsUngraded
Higher circulating 25-hydroxyvitamin D (25(OH)D) concentration vs Lower circulating 25-hydroxyvitamin D (25(OH)D) concentration
All cause mortality · Patients with chronic kidney disease
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
RR 0.86 [0.81, 0.92]10 studies · 6853 participantsUngraded
Higher circulating 25-hydroxyvitamin D (25(OH)D) concentration vs Lower circulating 25-hydroxyvitamin D (25(OH)D) concentration
Metabolic syndrome (prevalent) · Adults (general population)
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
OR 0.49 [0.38, 0.64]8 studies · 31416 participantsUngraded
Vitamin D supplementation vs Placebo or control
Performance measures: muscle strength · Older or community-dwelling adults
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
SMD -0.19 [-0.35, -0.02]3 studiesUngraded
Higher circulating 25-hydroxyvitamin D (25(OH)D) concentration vs Lower circulating 25-hydroxyvitamin D (25(OH)D) concentration
Cognition · Adults (general population)
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
OR 0.42 [0.34, 0.53]7 studies · 9004 participantsUngraded
Higher maternal circulating 25-hydroxyvitamin D (25(OH)D) concentration vs Lower maternal circulating 25-hydroxyvitamin D (25(OH)D) concentration
Pre-eclampsia · Pregnant women and their offspring
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
OR 0.56 [0.39, 0.80]9 studies · 3230 participantsUngraded
Vitamin D supplementation vs Placebo or control
Fractures: non-vertebral, non-hip · Older or community-dwelling adults
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
OR 0.69 [0.21, 1.66]2 studiesUngraded
Higher maternal circulating 25-hydroxyvitamin D (25(OH)D) concentration vs Lower maternal circulating 25-hydroxyvitamin D (25(OH)D) concentration
Head circumference · Pregnant women and their offspring
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
WMD 0.05 [-0.24, 0.34]2 studies · 840 participantsUngraded
Vitamin D supplementation vs Placebo or control
Diastolic blood pressure · Adults (general population)
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
WMD -0.03 [-1.98, 1.92]3 studiesUngraded
Vitamin D supplementation vs Placebo or control
Mean gestational age at delivery · Pregnant women
Vitamin D and multiple health outcomes: umbrella review of systematic reviews and meta-analyses of… (2014)
WMD 0.17 [-0.16, 0.51]2 studiesUngraded