Gap finder
Search review questions
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.
10,375 questions in 429 reviews · Oral Health
current versionsNo 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.
| Question | Effect | Evidence | Status / 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 70.4 | 1 study | Ungraded |
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 swelling | 2 studies · 54 participants | Low |
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 participants | Ungraded |
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 studies | Ungraded |
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 study | Ungraded |
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 study | Ungraded |
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 studies | Ungraded |
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 participants | Ungraded |
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 studies | 0 studies | No 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 studies | No 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 participants | Very 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 participants | High |
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 5.67 | 1 study | Ungraded |
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 participants | Very 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 study | Ungraded |
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 2.288 | 1 study | Ungraded |
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 0.73 | 2 studies | Ungraded |
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 studies | Ungraded |
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 participants | Ungraded |
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 participants | Ungraded |
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 study | Ungraded |
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 study | Ungraded |
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 0.63 | 3 studies | Ungraded |
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 participants | Moderate |
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 participants | Ungraded |
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 study | Ungraded |
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 studies | Ungraded |
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 study | Ungraded |
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 studies | Ungraded |
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 studies | No 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 studies | Ungraded |
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 participants | Very 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 participants | Low |
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] | NR | Ungraded |
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%… | NR | Ungraded |
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 studies | No 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 studies | Ungraded |
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 participants | Ungraded |
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 participants | Very 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 study | Ungraded |
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 participants | 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) | DOR 99 [22.01, 445.30] | 1 study | Ungraded |
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 studies | Ungraded |
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 participants | High |
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 participants | Ungraded |
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 studies | Ungraded |
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 participants | Very 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 0.92 | 2 studies | Ungraded |
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 studies | 0 studies | No 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 study | Ungraded |