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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
Autism spectrum disorder vs Not applicable
Generalized gingivitis prevalence · Autistic children and young adults in Dubai · Overall
Oral Health of Children and Adolescents in the United Arab Emirates: A Systematic Review of the Past Decade. (2021)
Prevalence 70.41 studyUngraded
ARP with xenograft (bone graft) vs Extraction alone
Complications (e.g. discomfort, pain and swelling) · Adults aged 18 years or older, in good general health (including well-controlled systemic disease), requiring… · 6 to 36 months
Interventions for replacing missing teeth: alveolar ridge preservation techniques for dental implant site… (2021) · Cochrane
1 trial (Cha 2019) reported delayed healing with partial exposure of the buccal plate at suture removal by 1 participant in the test group; another trial (Festa 2013) reported pain and swelling2 studies · 54 participantsLow
Higher number of lost teeth (per one additional lost tooth) vs Fewer lost teeth (continuous, per-tooth increment)
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 1.01 [1.00, 1.03]3 studies · 2219 participantsUngraded
Conventional bitewing radiography (E-speed film) 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)
DOR 10.69 [3.67, 31.15]2 studiesUngraded
Diode laser, near infrared (850 nm to 980 nm) vs Placebo (placebo laser or placebo agent) or no treatment
Changes in intensity of pain (VAS 0 to 10) tested through tactile stimuli · Patients aged above 12 years with self-reported tooth hypersensitivity confirmed on clinical evaluation · Medium term (24 hours to 2 months)
Laser therapy for dentinal hypersensitivity (2021) · Cochrane
MD -1.83 [-2.36, -1.30]1 studyUngraded
Maternal smoking during pregnancy vs No maternal smoking during pregnancy
Dental caries · Children · Community/population-based (multiple countries), Study region: United States
Asked by 2 reviewsCorrelation Between Maternal Smoking During Pregnancy and Dental Caries in Children: A Systematic Review and… (2021)
OR 1.68 [1.01, 2.79]1 studyUngraded
Crohn's disease (CD) vs Healthy controls without IBD
Periodontal disease (periodontitis) coincidence · Patients with Crohn's disease (CD) and controls without IBD; adults, both sexes · Hospital/clinic-based case-control and cross-sectional studies in 11 countries; 15 studies total (1748 participants: 1104 Crohn's disease, 534 ulcerative colitis, 110 IBD-form unspecified); 5 studies pooled for this analysis, Crohn's disease (CD) vs healthy controls
Oral Health Status in Patients with Inflammatory Bowel Diseases: A Systematic Review. (2021)
OR 2.10 [1.59, 2.78]5 studiesUngraded
Periodontal treatment (subgingival SRP with or without other periodontal treatment) vs No treatment (no periodontal treatment)
Plasma level of hs-CRP (mg/L) · Adults (any age/sex) with chronic periodontitis (>=5 teeth remaining; PPD >4 mm), with or without hypertension · Long term, People diagnosed with periodontitis and other cardiovascular diseases except hypertension
Effect of periodontal treatments on blood pressure (2021) · Cochrane
MD -0.72 [-1.74, 0.30]2 studies · 103 participantsUngraded
Glass ionomer cement vs Amalgam
Adverse events · Patients needing retrograde filling in root canal therapy (orthograde root canal filling or retreatment not possible;…
Materials for retrograde filling in root canal therapy (2021) · Cochrane
Adverse events: outcome was not assessed by the included studies0 studiesNo studies
Any of the interventions (CR, SE, SW, sealing with sealant materials, Hall Technique, or NRCC) vs Each other, placebo, or no treatment
Subjective evaluation of the treatments by participants · Children and/or adults with permanent or primary teeth, vital (sensitive) pulps, and cavitated or dentine carious…
Interventions for treating cavitated or dentine carious lesions (2021) · Cochrane
We found no studies reporting subjective evaluation of the treatments by participants.0 studiesNo studies
Double primary (canine and first molar) tooth extraction vs Single primary (canine) tooth extraction
Number of participants referred for surgical exposure of the PDC · Young people aged 9 to 14 years diagnosed with one or both palatally displaced permanent maxillary canines (PDC) · 48 months (maximum; mITT)
Interventions for promoting the eruption of palatally displaced permanent canine teeth, without the need for… (2021) · Cochrane
RR 0.31 [0.06, 1.45]2 studies · 96 participantsVery low
Edentulous (0 remaining teeth) vs 20-32 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 2.65 [1.77, 3.98]2 studies · 130669 participantsHigh
Special health care needs vs Not applicable
Mean dmft/DMFT · Arab children with special health care needs in Ras Al Khaimah · Overall
Oral Health of Children and Adolescents in the United Arab Emirates: A Systematic Review of the Past Decade. (2021)
MEAN 5.671 studyUngraded
Nickel-titanium archwire vs Multistranded stainless steel archwire
Amount of crowding (change in mandibular crowding) at 8 weeks · Children or adolescents (aged 16 years old or under) receiving orthodontic treatment to prevent or correct crowded teeth · 8 weeks
Orthodontic treatment for crowded teeth in children (2021) · Cochrane
MD 1.60 [-22.16, 25.36]1 study · 25 participantsVery low
Intensive periodontal treatment (subgingival SRP with or without other periodontal treatment) vs Supra-gingival scaling
Endothelial function (flow-mediated dilation) · Adults (any age/sex) with chronic periodontitis (>=5 teeth remaining; PPD >4 mm), with or without hypertension · Short term, People diagnosed with periodontitis
Effect of periodontal treatments on blood pressure (2021) · Cochrane
MD -0.25 [-1.30, 0.80]1 studyUngraded
Fixed bonded acrylic splint expander vs No treatment
Canine expansion (maxillary intercanine width) · 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
MD 2.2881 studyUngraded
Digital bitewing radiography (phosphor plates) 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)
AUC 0.732 studiesUngraded
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)
Specificity 0.87 [0.72, 0.95]8 studiesUngraded
TaqI (rs731236 T>C) polymorphism in the VDR gene (C allele / variant genotype) vs CC genotype vs TT genotype (homozygous 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: Deciduous tooth decay
Association Between the TaqI (rs731236 T>C) Gene Polymorphism and Dental Caries Risk: A Meta-analysis. (2021)
OR 1.28 [0.08, 21.28]2 studies · 929 participantsUngraded
Early childhood caries (ECC) vs ECC-free children (caries-free controls)
Hemoglobin (HGB) level · Preschool children (<6 years) · Overall
Iron deficiency and early childhood caries: a systematic review and meta-analysis. (2021)
WMD -9.96 [-15.45, -4.46]5 studies · 924 participantsUngraded
Intervention NR
Mean DMFT (decayed, missing, filled permanent teeth) · Somalia
Prevalence of Dental Caries and Associated Factors in East Africa, 2000-2020: Systematic Review and… (2021)
MEAN 2.200 [2.200, 2.200]1 studyUngraded
Beta-thalassemia major (oral health status) vs Healthy Emirati children
Oral health status (caries, calculus, gingivitis) · Children with beta-thalassemia major in the United Arab Emirates (Dubai) · Dubai, UAE
Oral Health of Children and Adolescents in the United Arab Emirates: A Systematic Review of the Past Decade. (2021)
Al-Raeesi et al. (Dubai) reported caries prevalence of 68.4% (mean DMFT 1.49) in children with beta-thalassemia major, higher than controls (48.7%; DMFT 0.21). More had calculus (28.9% vs 7.9%) and gingival…1 studyUngraded
Laser fluorescence (DIAGNOdent 2190/pen) 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)
AUC 0.633 studiesUngraded
Intensive periodontal treatment (subgingival SRP with or without other periodontal treatment) vs Supra-gingival scaling
Change in systolic blood pressure (SBP, mmHg) · Adults (any age/sex) with chronic periodontitis (>=5 teeth remaining; PPD >4 mm), with or without hypertension · Short term (follow-up 2 months), People diagnosed with periodontitis and hypertension
Effect of periodontal treatments on blood pressure (2021) · Cochrane
MD -11.2 [-15.4, -7.0]1 study · 101 participantsModerate
Daily supervised brushing with fluoridated toothpaste vs Pre-intervention
Visible plaque prevalence · Schoolchildren aged 4-6 years in Dubai schools · Overall
Oral Health of Children and Adolescents in the United Arab Emirates: A Systematic Review of the Past Decade. (2021)
Visible plaque index (pre-post) 76.8% (pre) to 36.7% (post)1 study · 1500 participantsUngraded
Maternal smoking during pregnancy vs No maternal smoking during pregnancy
Dental caries · Children · Community/population-based (multiple countries), Caries assessment: clinical and radiographic examination
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]1 studyUngraded
Intensive periodontal treatment (subgingival SRP with or without other periodontal treatment) vs Supra-gingival scaling
Plasma level of hs-CRP (mg/L) · Adults (any age/sex) with chronic periodontitis (>=5 teeth remaining; PPD >4 mm), with or without hypertension · Long term, People diagnosed with periodontitis
Effect of periodontal treatments on blood pressure (2021) · Cochrane
MD -0.16 [-2.15, 1.83]2 studiesUngraded
Digital bitewing radiography, sensor-based (CCD/CMOS) 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)
DOR 17.11 [3.73, 78.39]1 studyUngraded
Conventional bitewing radiography, E-speed film 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)
Specificity 0.94 [0.71, 0.99]5 studiesUngraded
Blood and saliva analysis (biomarker tests) vs Surgical or punch biopsy with histological assessment
Outcome NR · 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
No eligible studies assessed the diagnostic test accuracy of blood and saliva analysis; potentially eligible biomarker studies were excluded as case-control designs.0 studiesNo studies
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)
DOR 5.93 [3.11, 11.31]8 studiesUngraded
ARP with xenograft (bone graft) vs Extraction alone
Implant failure rate · Adults aged 18 years or older, in good general health (including well-controlled systemic disease), requiring… · 6 to 36 months
Interventions for replacing missing teeth: alveolar ridge preservation techniques for dental implant site… (2021) · Cochrane
RR 1.0 [0.07, 14.9]2 studies · 70 participantsVery low
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, Multivariable-adjusted
Lower Number of Teeth Is Related to Higher Risks for ACVD and Death-Systematic Review and Meta-Analyses of… (2021)
HR 1.29 [1.21, 1.37]10 studies · 305970 participantsLow
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), Primary/mixed dentition
Visual or visual‐tactile examination to detect and inform the diagnosis of enamel caries (2021) · Cochrane
Specificity 0.79 [0.70, 0.85]NRUngraded
Oral hygiene knowledge and practices assessment vs None (descriptive prevalence review)
Oral hygiene knowledge and practices · Children and adolescents in the United Arab Emirates · UAE; schools/nurseries (Sharjah, Ajman; national survey)
Oral Health of Children and Adolescents in the United Arab Emirates: A Systematic Review of the Past Decade. (2021)
Suboptimal oral hygiene practices were common. Kowash reported 63% poor oral hygiene among preschoolers (58% never/rarely brushing). In a national survey (Pengpid et al.), tooth brushing less than once daily was 46.1%…NRUngraded
COE with blood/salivary (biomarker) analysis vs COE with vital rinsing (toluidine blue/tolonium chloride)
Outcome NR · Apparently healthy adults not reporting symptoms of OPMD or OSCC, attending an organised screening or surveillance…
Clinical assessment for the detection of oral cavity cancer and potentially malignant disorders in… (2021) · Cochrane
No eligible studies; planned comparative analysis (COE with vital rinse vs COE with blood/salivary analysis) not populated in this version.0 studiesNo studies
Maternal smoking during pregnancy vs No maternal smoking during pregnancy
Dental caries · Children · Community/population-based (multiple countries), Sample size: 3,000 or fewer
Asked by 2 reviewsCorrelation Between Maternal Smoking During Pregnancy and Dental Caries in Children: A Systematic Review and… (2021)
OR 1.61 [1.30, 2.01]4 studiesUngraded
Edentulous (0 remaining teeth) vs 1-32 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, Crude
Lower Number of Teeth Is Related to Higher Risks for ACVD and Death-Systematic Review and Meta-Analyses of… (2021)
HR 1.89 [1.80, 1.99]3 studies · 98122 participantsUngraded
Rubber dam isolation and moisture control (alone or with saliva aspiration) vs Cotton rolls (with or without saliva aspiration)
Survival rate of restorations (24 months) · Dental patients undergoing direct or indirect restorative treatment (no age or gender restriction) · 24 months, Primary molars (proximal atraumatic restorative treatment)
Rubber dam isolation for restorative treatment in dental patients (2021) · Cochrane
HR 0.80 [0.66, 0.97]1 study · 559 participantsVery low
Digital bitewing radiography, sensor-based (CCD/CMOS) 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)
Sensitivity 0.96 [0.91, 0.98]1 studyUngraded
Higher number of lost teeth (per one additional lost tooth) vs Fewer lost teeth (continuous, per-tooth increment)
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, Multivariable-adjusted
Lower Number of Teeth Is Related to Higher Risks for ACVD and Death-Systematic Review and Meta-Analyses of… (2021)
HR 1.02 [1.01, 1.03]13 studies · 4639644 participantsLow
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)
DOR 99 [22.01, 445.30]1 studyUngraded
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), Province: Sindh
Prevalence of dental caries in Pakistan: a systematic review and meta-analysis. (2021)
Prevalence 58.946 [43.796, 73.274]11 studiesUngraded
Fixed tooth-borne expansion (quad-helix) vs Removable tooth-borne expansion (expansion plate)
Molar expansion (inter-molar distance) · 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
MD 1.48 [0.91, 2.04]3 studies · 151 participantsHigh
Double primary (canine and first molar) tooth extraction vs Single primary (canine) tooth extraction
Incidence of eruption of the PDC into the mouth · Young people aged 9 to 14 years diagnosed with one or both palatally displaced permanent maxillary canines (PDC) · 24 months
Interventions for promoting the eruption of palatally displaced permanent canine teeth, without the need for… (2021) · Cochrane
RR 0.61 [0.29, 1.25]1 study · 23 participantsUngraded
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 >= 3 years, Split-mouth trials
Direct composite resin fillings versus amalgam fillings for permanent posterior teeth (2021) · Cochrane
RR 1.33 [0.84, 2.11]6 studiesUngraded
In-office laser therapy (all types combined) vs Placebo (placebo laser or placebo agent) or no treatment
Changes in intensity of pain (VAS 0 to 10) tested through tactile stimuli · Patients aged above 12 years with self-reported tooth hypersensitivity confirmed on clinical evaluation · Long term (more than 2 months)
Laser therapy for dentinal hypersensitivity (2021) · Cochrane
MD -3.52 [-10.37, 3.33]2 studies · 184 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)
AUC 0.922 studiesUngraded
Mineral trioxide aggregate (MTA) vs Intermediate restorative material (IRM)
Adverse events · Patients needing retrograde filling in root canal therapy (orthograde root canal filling or retreatment not possible;…
Materials for retrograde filling in root canal therapy (2021) · Cochrane
Adverse events: outcome was not assessed by the included studies0 studiesNo studies
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)
Diagnostic accuracy in previously restored teeth (secondary 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), Previously restored teeth (secondary caries)
Visual or visual‐tactile examination to detect and inform the diagnosis of enamel caries (2021) · Cochrane
Only one study (Kim 2017) intentionally included restored teeth in its sample; the pre-specified secondary-caries subgroup analysis could not be performed, no summary estimate reported.1 studyUngraded