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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. Every word you type has to appear somewhere in the question, and the closest matches are ranked first.

Limit to evidence status or GRADE (optional)

10,375 questions in 429 reviews · Oral Health

current versions
No studies 1,344 · 13%Ungraded 6,832 · 65.9%Very low 1,228 · 11.8%Low 613 · 5.9%Moderate 290 · 2.8%High 68 · 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
Direct composite resin restoration vs Amalgam restoration
Restoration failure rate · People with permanent or adult posterior teeth requiring restoration (parallel-group trials involved children aged 6… · Follow-up: 5 to 7 years
Direct composite resin fillings versus amalgam fillings for permanent posterior teeth (2021) · Cochrane
RR 1.89 [1.52, 2.35]2 studies · 921 participantsLow
Chemotherapy (any regimen; added to, or compared with, locoregional treatment) vs Locoregional treatment and/or an alternative chemotherapy regimen
Quality of life · People receiving curative-intent treatment for oral cavity and oropharyngeal (squamous cell) cancer
Interventions for the treatment of oral cavity and oropharyngeal cancer: chemotherapy (2021) · Cochrane
Quality of life was a planned (protocol) outcome but no included trial provided usable quality-of-life data; the protocol was modified to report only survival/response outcomes.0 studiesNo studies
Radiographic imaging methods (any: analogue radiographs, digital radiographs, or CBCT) vs Reference standard (histology, excavation, or enhanced visual examination)
Sensitivity for detection and diagnosis of early (enamel) caries · Asymptomatic children, adolescents, or adults presenting for clinical examination (in vivo studies), or extracted… · Up to 3 months between index test and reference standard (in vivo studies), Dentine-caries (D3) prevalence low <15% (non-CBCT)
Imaging modalities to inform the detection and diagnosis of early caries (2021) · Cochrane
Sensitivity 0.36 [0.25, 0.47]NRUngraded
Resin infiltration vs Untreated control (natural remineralization)
Optical/esthetic improvement (visual-tactile assessment) · Patients with post-orthodontic white spot lesions (WSL) · 4 weeks to 6 months
Efficacy of resin infiltration to mask post-orthodontic or non-post-orthodontic white spot lesions or… (2021)
SMD 1.24 [0.59, 1.88]3 studies · 949 participantsModerate
Systemic sclerosis (SSc / scleroderma) vs SSc-free individuals (controls)
Probing depth (PD) · Adults (general and hospital populations assessed in case-control studies) · Hospital/clinic-based case-control studies from Asia, America and Europe, Other/non-Asia (Da Silva 2019, Iordache 2019, Isola 2017, Pischon 2016)
Oral manifestations of patients with systemic sclerosis: a meta-analysis for case-controlled studies. (2021)
SMD 4.86 [1.61, 8.10]4 studiesUngraded
Laser fluorescence (DIAGNOdent 2095) vs Cavity preparation or biopsy (operative validation)
Diagnostic accuracy for occlusal caries detection at the caries detection level (D0 versus D1-D4) · Human permanent posterior teeth (premolars and molars) in patients, occlusal (pit-and-fissure) surfaces · in vivo
Systematic review and meta-analysis of diagnostic methods for occlusal surface caries. (2021)
DOR 18.33 [7.57, 44.37]1 studyUngraded
Digital bitewing radiography, sensor-based (CCD/CMOS) vs Histological validation of dental tissues (gold standard)
Diagnostic accuracy for proximal caries detection (dentin detection level) · Extracted permanent posterior teeth with proximal surfaces (in vitro) · In vitro (laboratory; extracted teeth); permanent posterior teeth, proximal surfaces, Dentin detection level
Systematic review and meta-analysis of diagnostic studies of proximal surface caries. (2021)
DOR 12.84 [6.56, 25.13]4 studiesUngraded
Dental erosion assessment vs None (descriptive prevalence review)
Dental erosion prevalence · Preschool children (5-year-olds) in the United Arab Emirates (Sharjah) · Sharjah, UAE; kindergarten
Oral Health of Children and Adolescents in the United Arab Emirates: A Systematic Review of the Past Decade. (2021)
Among 5-year-olds in Sharjah (n=403), Gopinath reported dental erosion in 58.8% and dissolution of enamel in 55.0% (exposed dentin 3.7%). Predictors of erosion included Arab non-Emirati nationality (OR 0.27, 95% CI…1 study · 403 participantsUngraded
Visual examination (VE) vs Histological validation (serial sectioning, grinding, hemisection, or microradiography)
Diagnostic accuracy for occlusal caries detection at the dentin caries detection level (D0-2 versus D3-4) · Extracted human permanent posterior teeth (premolars and molars), occlusal (pit-and-fissure) surfaces · in vitro
Systematic review and meta-analysis of diagnostic methods for occlusal surface caries. (2021)
Sensitivity 0.46 [0.20, 0.73]8 studiesUngraded
Intervention NR
Dental caries prevalence · General population (children and adults) in East Africa · Community- and school-based populations, East Africa
Prevalence of Dental Caries and Associated Factors in East Africa, 2000-2020: Systematic Review and… (2021)
Prevalence 0.457 [0.380, 0.534]44 studiesUngraded
Observed population vs Not applicable
Care index · Preschool children attending Al Ain pediatric dentistry department · Overall
Oral Health of Children and Adolescents in the United Arab Emirates: A Systematic Review of the Past Decade. (2021)
Proportion 6.41 study · 176 participantsUngraded
ARP with allograft vs ARP with xenograft
Complications (e.g. discomfort, pain and swelling) · Adults aged 18 years or older, in good general health (including well-controlled systemic disease), requiring… · 6 months
Interventions for replacing missing teeth: alveolar ridge preservation techniques for dental implant site… (2021) · Cochrane
1 trial (Scheyer 2016) reported moderate glazing, redness and oedema, while 2 trials (Santana 2019; Serrano Mendez 2017) reported there were no adverse events3 studies · 87 participantsLow
Maternal smoking during pregnancy vs No maternal smoking during pregnancy
Dental caries · Children · Community/population-based (multiple countries), Sample size: over 3,000
Asked by 2 reviewsCorrelation Between Maternal Smoking During Pregnancy and Dental Caries in Children: A Systematic Review and… (2021)
OR 1.56 [1.46, 1.67]2 studiesUngraded
Vibrational appliance with fixed appliances vs Fixed appliances only / no vibrational appliance (control)
Harms (discomfort, pain intensity, analgesia use) · Children or adolescents (aged 16 years old or under) receiving orthodontic treatment to prevent or correct crowded teeth · first week
Orthodontic treatment for crowded teeth in children (2021) · Cochrane
No clear difference in discomfort/pain intensity or analgesia consumption between vibrational appliance and control (Miles 2012, Miles 2016, Woodhouse 2015; 100 mm VAS). Narrative; no pooled estimate.2 studiesUngraded
Rubber dam isolation and moisture control (alone or with saliva aspiration) vs Cotton rolls (with or without saliva aspiration)
Survival rate of restorations (6 months) · Dental patients undergoing direct or indirect restorative treatment (no age or gender restriction) · 6 months, Non-carious cervical lesions (composite restoration)
Rubber dam isolation for restorative treatment in dental patients (2021) · Cochrane
OR 2.29 [1.05, 4.99]2 studies · 192 participantsLow
CarieScan Pro device vs Reference standard: histology or enhanced visual examination (with or without radiographs)
Sensitivity · Children, adolescents, or adults presenting asymptomatically or suspected of early enamel caries (in vivo), or… · Up to 3 months between index test and reference standard (in vivo studies)
Electrical conductance for the detection of dental caries (2021) · Cochrane
CarieScan Pro (3 studies, 244 tooth surfaces): sensitivity ranged from 0.55 to 0.91. No evidence of a difference in accuracy by device type (Chi2=0.05, df=1, P=0.82).3 studiesUngraded
Super ethoxybenzoic acid (Super-EBA) vs Intermediate restorative material (IRM)
Success rate at 1 year · Patients needing retrograde filling in root canal therapy (orthograde root canal filling or retreatment not possible;… · 1 year
Materials for retrograde filling in root canal therapy (2021) · Cochrane
RR 0.90 [0.80, 1.01]1 studyVery low
External control of fluoride concentration vs Not applicable
Samples with fluoride concentration below the acceptable range · Brazilian cities in the Southeast region with artificially fluoridated public water supplies · 1995-2013, Brazilian Southeast, Southeast region
External control of fluoridation in the public water supplies of Brazilian cities as a strategy against… (2021)
Prevalence 24.6NRUngraded
17-24 remaining teeth vs 25-32 remaining teeth
Atherosclerotic cardiovascular disease (ACVD)-related events (morbidity and mortality) · Adults (any age) with a known number of remaining teeth, followed prospectively in cohort studies · Community-based and clinical cohorts worldwide (all continents); events ascertained from medical records, death certificates/registers, or self-report
Lower Number of Teeth Is Related to Higher Risks for ACVD and Death-Systematic Review and Meta-Analyses of… (2021)
RR 1.73 [1.22, 2.45]4 studies · 213202 participantsHigh
0-19 remaining teeth vs 20-32 remaining teeth
All-cause mortality (ACM) · Adults (any age) with a known number of remaining teeth, followed prospectively in cohort studies · Community-based and clinical cohorts worldwide (all continents); events ascertained from medical records, death certificates/registers, or self-report, Crude
Lower Number of Teeth Is Related to Higher Risks for ACVD and Death-Systematic Review and Meta-Analyses of… (2021)
HR 2.47 [2.40, 2.54]2 studies · 36379 participantsUngraded
Digital bitewing radiography, phosphor plate (PSP) vs Histological validation of dental tissues (gold standard)
Diagnostic accuracy for proximal caries detection (caries detection level) · Extracted permanent posterior teeth with proximal surfaces (in vitro) · In vitro (laboratory; extracted teeth); permanent posterior teeth, proximal surfaces, Caries detection level
Systematic review and meta-analysis of diagnostic studies of proximal surface caries. (2021)
AUC 0.8211 studiesUngraded
Conventional bitewing radiography, E-speed film vs Direct visual examination after tooth separation or bioptical cavity preparation
Diagnostic accuracy for proximal caries detection (dentin detection level) · Patients with permanent posterior teeth, proximal surfaces assessed clinically (in vivo) · In vivo (clinical); permanent posterior teeth, proximal surfaces, Dentin detection level
Systematic review and meta-analysis of diagnostic studies of proximal surface caries. (2021)
Specificity 0.91 [0.80, 0.96]1 studyUngraded
0-19 remaining teeth vs 20-32 remaining teeth
All-cause mortality (ACM) · Adults (any age) with a known number of remaining teeth, followed prospectively in cohort studies · Community-based and clinical cohorts worldwide (all continents); events ascertained from medical records, death certificates/registers, or self-report
Lower Number of Teeth Is Related to Higher Risks for ACVD and Death-Systematic Review and Meta-Analyses of… (2021)
RR 1.84 [1.52, 2.23]11 studies · 267575 participantsLow
Any orthodontic (non-surgical) treatment to correct posterior crossbite or expand the top teeth vs No treatment or another orthodontic treatment
Signs and symptoms of respiratory issues · Children and adults with a posterior crossbite, without a Class III skeletal relationship, cleft lip or palate (or…
Orthodontic treatment for posterior crossbites (2021) · Cochrane
no estimate extracted0 studiesNo studies
Fluoride-releasing coating material vs Coating material without fluoride release
Incidence of new white spot lesions by visual-tactile assessment · Patients receiving comprehensive fixed orthodontic treatment · 1 to 24 months, Fixed orthodontic treatment, Overall
Efficacy of sealants and bonding materials during fixed orthodontic treatment to prevent enamel… (2021)
RR 0.84 [0.70, 1.01]10 studies · 4705 participantsVery low
Laser fluorescence (DIAGNOdent 2190/pen) vs Direct visual examination after tooth separation or bioptical cavity preparation
Diagnostic accuracy for proximal caries detection (caries detection level) · Patients with permanent posterior teeth, proximal surfaces assessed clinically (in vivo) · In vivo (clinical); permanent posterior teeth, proximal surfaces, Caries detection level
Systematic review and meta-analysis of diagnostic studies of proximal surface caries. (2021)
AUC 0.961 studyUngraded
Er,Cr:YSGG laser (erbium,chromium:yttrium-scandium-gallium-garnet) vs Placebo (placebo laser or placebo agent) or no treatment
Changes in intensity of pain (VAS 0 to 10) tested through air blast stimuli · Patients aged above 12 years with self-reported tooth hypersensitivity confirmed on clinical evaluation · Short term (0 to 24 hours)
Laser therapy for dentinal hypersensitivity (2021) · Cochrane
MD -4.61 [-4.83, -4.39]3 studiesUngraded
Dentine-bonded resin composite vs Glass ionomer cement
Success rate at 1 year (root as unit, per-protocol analysis) · Patients needing retrograde filling in root canal therapy (orthograde root canal filling or retreatment not possible;… · 1 year, Root as unit of analysis (radiological), per-protocol (PP)
Materials for retrograde filling in root canal therapy (2021) · Cochrane
RR 1.59 [1.20, 2.09]1 studyVery low
Dental caries (ascertained mostly by WHO criteria/DMFT; also CAST, ICDAS, or clinical examination) vs None (descriptive prevalence meta-analysis)
Dental caries prevalence · General Pakistani population (all ages and both sexes; predominantly children and adolescents) · Pakistan (school-, community-, and hospital/clinic-based cross-sectional surveys), Dentition: permanent
Prevalence of dental caries in Pakistan: a systematic review and meta-analysis. (2021)
Prevalence 57.184 [26.288, 85.251]NRUngraded
Double primary (canine and first molar) tooth extraction vs Single primary (canine) tooth extraction
Effect of severity of PDC displacement towards the midline on the proportion of successful eruptions · Young people aged 9 to 14 years diagnosed with one or both palatally displaced permanent maxillary canines (PDC) · 12 to 48 months, By baseline sector (severity of displacement)
Interventions for promoting the eruption of palatally displaced permanent canine teeth, without the need for… (2021) · Cochrane
Tables 11-15 (Hadler-Olsen 2020; Bonetti 2010; Bonetti 2011): partial relationship between severity of medial displacement and successful eruption; e.g. at 18 months 17/75 (23%) sector 2 erupted vs 1/17 (6%) sector 3,…3 studiesUngraded
Removable tooth-borne expansion (expansion plate) vs Observation (no treatment)
Crossbite correction · Children and adults with a posterior crossbite, without a Class III skeletal relationship, cleft lip or palate (or… · Children (7 to 11 years)
Orthodontic treatment for posterior crossbites (2021) · Cochrane
OR 25.26 [13.08, 48.77]3 studies · 148 participantsHigh
Micro-invasive treatment (resin infiltration or sealing) vs Non-invasive / control treatment
Radiographic proximal caries lesion progression · Patients with non-cavitated proximal (approximal) caries lesions (primary or permanent dentition) · Longest available follow-up, Caries risk: low
Infiltration and sealing for managing non-cavitated proximal lesions: a systematic review and meta-analysis. (2021)
OR 0.24 [0.08, 0.72]2 studiesUngraded
Analogue (conventional) radiographs vs Digital radiographs (direct within-person / paired comparison); reference standard: histology, excavation, or enhanced visual examination
Specificity for detection and diagnosis of early (enamel) caries · Asymptomatic children, adolescents, or adults presenting for clinical examination (in vivo studies), or extracted… · Up to 3 months between index test and reference standard (in vivo studies), Analogue
Imaging modalities to inform the detection and diagnosis of early caries (2021) · Cochrane
Specificity 0.91 [0.86, 0.94]15 studiesUngraded
Sealing using sealant materials vs Selective carious tissue removal (selective excavation, SE)
Failure of therapy · Children and/or adults with permanent or primary teeth, vital (sensitive) pulps, and cavitated or dentine carious… · 18-24 months, Cavitated lesions, primary dentition
Interventions for treating cavitated or dentine carious lesions (2021) · Cochrane
OR 3.11 [0.11, 85.52]2 studies · 82 participantsVery low
TaqI (rs731236 T>C) polymorphism in the VDR gene (C allele / variant genotype) vs CT/CC genotype vs TT genotype (dominant model)
Dental caries susceptibility (risk of dental caries) · Children and adults (no age limit) assessed for dental caries susceptibility · Case-control studies of children and adults (China, India, Czech Republic, Turkey), Dentition: Permanent tooth caries
Association Between the TaqI (rs731236 T>C) Gene Polymorphism and Dental Caries Risk: A Meta-analysis. (2021)
OR 1.78 [0.41, 7.73]3 studies · 1271 participantsUngraded
Fixed tooth-borne expansion (Hyrax) vs Fixed tooth-tissue-borne expansion (Haas)
Crossbite correction · Children and adults with a posterior crossbite, without a Class III skeletal relationship, cleft lip or palate (or… · Children
Orthodontic treatment for posterior crossbites (2021) · Cochrane
RR 1.05 [0.94, 1.18]3 studies · 83 participantsModerate
Fluoride concentration relative to the acceptable range (electrometric ion-selective electrode measurement; acceptable range mostly 0.6-0.8 ppmF) vs None (descriptive proportion meta-analysis)
Water samples with fluoride concentration below the acceptable range · Artificially fluoridated public water supply in Brazilian cities (water samples under external control) · Public water supply / water treatment stations in Brazilian cities (external control of artificial fluoridation), Region: Northeast Brazil
External control of fluoridation in the public water supplies of Brazilian cities as a strategy against… (2021)
Prevalence 79.7NRUngraded
Two-band palatal expander with slow expansion vs Two-band palatal expander with rapid expansion
Molar expansion · Children and adults with a posterior crossbite, without a Class III skeletal relationship, cleft lip or palate (or… · 7 months after start of treatment
Orthodontic treatment for posterior crossbites (2021) · Cochrane
Martina 2012: slow 6.3 mm (SD 2.1) vs rapid 5.7 mm (SD 1.6); reported as no statistically significant difference in text (PUB2 MD 0.60, 95% CI -0.85 to 2.05); Table 1 lists P<0.001 (discrepant)1 study · 26 participantsUngraded
Intervention NR
Dental caries prevalence · Ethiopia
Prevalence of Dental Caries and Associated Factors in East Africa, 2000-2020: Systematic Review and… (2021)
Prevalence 0.440 [0.326, 0.553]12 studiesUngraded
Extraction of the primary (baby) canine (single primary tooth extraction) vs No extraction (non-intervention control)
Reported improvement in the position of the ectopic canine measured from radiographs · Young people aged 9 to 14 years diagnosed with one or both palatally displaced permanent maxillary canines (PDC)
Interventions for promoting the eruption of palatally displaced permanent canine teeth, without the need for… (2021) · Cochrane
Improvement in the position of the ectopic canine was not extracted as a distinct outcome (alpha-angle was the trial's own outcome).0 studiesNo studies
Any orthodontic (non-surgical) treatment to correct posterior crossbite or expand the top teeth vs No treatment or another orthodontic treatment
Quality of life · Children and adults with a posterior crossbite, without a Class III skeletal relationship, cleft lip or palate (or…
Orthodontic treatment for posterior crossbites (2021) · Cochrane
no estimate extracted0 studiesNo studies
Lower lip bumper vs No active treatment (control)
Amount of crowding (change in mandibular incisor crowding) at 6 months · Children or adolescents (aged 16 years old or under) receiving orthodontic treatment to prevent or correct crowded teeth · 6 months
Orthodontic treatment for crowded teeth in children (2021) · Cochrane
MD -4.39 [-5.07, -3.71]1 study · 34 participantsVery low
Fibre-optic transillumination (FOTI) vs Histological validation (serial sectioning, grinding, hemisection, or microradiography)
Diagnostic accuracy for occlusal caries detection at the dentin caries detection level (D0-2 versus D3-4) · Extracted human permanent posterior teeth (premolars and molars), occlusal (pit-and-fissure) surfaces · in vitro
Systematic review and meta-analysis of diagnostic methods for occlusal surface caries. (2021)
Specificity 0.97 [0.89, 0.994]2 studiesUngraded
Visual or visual-tactile classification systems (any system: ICDAS, ERK, Nyvad, Downer, Lussi, UniViSS, or unspecified) vs Reference standard (histology, excavation, radiographs/microCT, or tooth separation)
Specificity for detection of enamel caries · Asymptomatic children or adults presenting for clinical examination (in vivo studies), or extracted teeth of children… · Up to 3 months between index test and reference standard (in vivo studies), Histology reference standard
Visual or visual‐tactile examination to detect and inform the diagnosis of enamel caries (2021) · Cochrane
Specificity 0.76 [0.69, 0.81]NRUngraded
Observed population vs Not applicable
Dental caries prevalence · School children aged 15-17 years in Dubai schools · Overall
Oral Health of Children and Adolescents in the United Arab Emirates: A Systematic Review of the Past Decade. (2021)
Prevalence 42.41 study · 2063 participantsUngraded
Oral cytology (e.g. brush cytology, OralCDx brush biopsy) vs Surgical or punch biopsy with histological assessment
Sensitivity · Adults (aged 16 years or over) presenting to primary or secondary care with clinically evident suspicious or innocuous…
Diagnostic tests for oral cancer and potentially malignant disorders in patients presenting with clinically… (2021) · Cochrane
Sensitivity 0.90 [0.82, 0.94]20 studiesModerate
Clear aligners (Invisalign / thermoformed aligners) vs Fixed appliances
Lactobacilli presence (CFU > 10^5) · Adults undergoing orthodontic treatment · 3 months, Adults
Impact of Aligners and Fixed Appliances on Oral Health during Orthodontic Treatment: A Systematic Review and… (2021)
RR 0.09 [0.02, 0.47]2 studies · 140 participantsLow
Non-selective carious tissue removal and conventional restoration (CR) vs Selective carious tissue removal (selective excavation, SE)
Failure of therapy · Children and/or adults with permanent or primary teeth, vital (sensitive) pulps, and cavitated or dentine carious… · 12-18 months, Deep lesions, permanent dentition
Interventions for treating cavitated or dentine carious lesions (2021) · Cochrane
OR 11.32 [1.97, 65.02]2 studies · 179 participantsVery low
Rubber dam isolation and moisture control (alone or with saliva aspiration) vs Cotton rolls (with or without saliva aspiration)
Survival rate of restorations (18 months) · Dental patients undergoing direct or indirect restorative treatment (no age or gender restriction) · 18 months, Non-carious cervical lesions (composite restoration)
Rubber dam isolation for restorative treatment in dental patients (2021) · Cochrane
OR 1.00 [0.45, 2.25]1 study · 30 participantsVery low
Analogue (conventional) radiographs vs Reference standard (histology, excavation, or enhanced visual examination)
Specificity for detection and diagnosis of early (enamel) caries · Asymptomatic children, adolescents, or adults presenting for clinical examination (in vivo studies), or extracted… · Up to 3 months between index test and reference standard (in vivo studies)
Imaging modalities to inform the detection and diagnosis of early caries (2021) · Cochrane
Specificity 0.90 [0.86, 0.93]51 studiesUngraded