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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. Words match anywhere in the field.
75,239 questions in 5,342 reviews
current versionsNo studies 15,213 · 20.2%Ungraded 10,323 · 13.7%Very low 17,528 · 23.3%Low 17,951 · 23.9%Moderate 11,190 · 14.9%High 3,034 · 4%
Ungraded means an effect was reported without a GRADE rating; it is not a gap. No studies means the review found nothing to answer the question. The six categories are a display order, not a score.
| Question | Effect | Evidence | Status / GRADE |
|---|---|---|---|
Overweight/obesity (combined) vs Normal weight (eutrophic) Dental caries prevalence (any DMFT), dichotomous · Brazilian children/adolescents in permanent dentition (BMI classified by WHO 2007 Z-score) Overweight/obesity and dental caries in Brazilian children and adolescents: a systematic review and… (2024) | OR 0.93 [0.78, 1.12] | 2 studies | Low |
Abdominal dermal fat graft vs Nasolabial flap Maximal mouth opening (interincisal distance) · People of any age with a confirmed diagnosis, by clinical examination and biopsy, of oral submucous fibrosis (OSF) · 3 to 6 months Interventions for managing oral submucous fibrosis (2024) · Cochrane | MD -14.87 [-19.93, -9.81] | 1 study · 30 participants | Very low |
Buccal fat pad graft vs Extended nasolabial flap Maximal mouth opening (interincisal distance) · People of any age with a confirmed diagnosis, by clinical examination and biopsy, of oral submucous fibrosis (OSF) · 3 to 6 months Interventions for managing oral submucous fibrosis (2024) · Cochrane | MD 6.00 [-11.36, 23.36] | 1 study · 8 participants | Very low |
Thermoelastic copper NiTi (CuNiTi) arch wire vs Conventional NiTi arch wire Alignment rate · People receiving orthodontic treatment with fixed appliances (upper and/or lower full arch) · 4 weeks Initial arch wires used in orthodontic treatment with fixed appliances (2024) · Cochrane | MD 0.10 [-0.95, 1.15] | 1 study · 66 participants | Very low |
Periodontitis vs No periodontitis (periodontal health or gingivitis) Root caries · Adults · Root caries Association between periodontitis and dental caries: a systematic review and meta-analysis. (2024) | OR 2.10 [1.03, 4.29] | 4 studies | Ungraded |
Slum / urban-disadvantaged setting vs Non-slum urban / general-urban / national population Use of toothbrush and toothpaste for mouth cleaning · Adult residents of slums and non-slum urban settings of LMICs · Cross-sectional, Slum/disadvantaged/rural vs non-slum/urban Systematic review of oral health in slums and non-slum urban settings of Low and Middle-Income Countries… (2024) | Eleven studies addressed practices; toothbrush and toothpaste were the commonest cleaning method but their use was lower among slum/disadvantaged/rural groups than non-slum/urban groups (e.g., Osuh 78% slum vs 94%… | 11 studies | Ungraded |
Intervention NR Dental caries (early childhood caries) · Narrative single study (Ganesh 2022): BF during sleep Association of Breastfeeding and Early Childhood Caries: A Systematic Review and Meta-Analysis. (2024) | AOR 6.5 | 1 study | Ungraded |
Adjunctive antimicrobial photodynamic therapy (aPDT) applied after submucosal instrumentation (SI) vs Submucosal instrumentation (SI) alone, or SI plus placebo/sham aPDT Outcome NR · Adults (> 18 years) with peri-implant mucositis, receiving supportive treatment Adjunctive antimicrobial photodynamic therapy for treating periodontal and peri‐implant diseases (2024) · Cochrane | Planned comparison; no studies met the inclusion criteria. The review found only one study of peri-implant disease (peri-implant mucositis, active treatment) and no studies including people with peri-implantitis… | NR | No studies |
Not applicable (single-group prevalence) vs Not applicable (single-group prevalence) Early childhood caries experience (mean dmft) · Children younger than 71 months (under 6 years) · Region: Asia-Oceania A systematic review and meta-analysis on early-childhood-caries global data. (2024) | MEAN 3.87 [2.84, 4.91] | 30 studies | Ungraded |
TT genotype vs TC+CC genotypes Dental caries · Children (<18 years) with vs without dental caries · Recessive model (TT vs TC+CC), Permanent dentition Association of vitamin D receptor gene polymorphisms with caries risk in children: a systematic review and… (2024) | OR 1.36 [0.89, 2.08] | NR | Ungraded |
Single preoperative dose of systemic antibiotics (clindamycin 600 mg), total chemo-mechanical debridement and root filling vs Matched placebo, total chemo-mechanical debridement and root filling Swelling at 7 days · Adults with symptomatic apical periodontitis (no signs of spreading infection or systemic involvement) · 7 days Systemic antibiotics for symptomatic apical periodontitis and acute apical abscess in adults (2024) · Cochrane | RR 0.50 [0.10, 2.56] | 1 study · 72 participants | Low |
Consumption of xylitol chewing gum by women (mothers) vs Consumption of CHX/xylitol gum by women, or CHX varnish applied to women's dentition Mother microbiological presence (mutans streptococci colonisation level, CFU/mL) · For interventions, pregnant women and mothers of infants in the first year of life; for outcomes, children up to 6… Interventions with pregnant women, new mothers and other primary caregivers for preventing early childhood… (2024) · Cochrane | MD 0.50 [0.15, 0.85] | 1 study · 126 participants | Ungraded |
Prenatal vitamin D deficiency measured at 6 to 38 gestational weeks vs Normal or sufficient prenatal vitamin D level Dental caries · Children aged 2 to 8 years · Maternal gestational weeks 6 to 38, Vitamin D measurement at 6 to 38 gestational weeks Association between prenatal vitamin D deficiency with dental caries in infants and children: a systematic… (2024) | OR 1.32 | NR | Ungraded |
Facemask vs Untreated control (no treatment) ANB · Children and adolescents (aged 16 years or younger) with prominent lower front teeth (Class III malocclusion) · 3-year follow-up Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children (2024) · Cochrane | MD 1.40 [0.43, 2.37] | 1 study · 63 participants | Moderate |
Vasodilators (isoxsuprine, xanthinol nicotinate) vs Placebo or no active treatment Burning sensation (VAS 0-100) · People of any age with a confirmed diagnosis, by clinical examination and biopsy, of oral submucous fibrosis (OSF) · 3 to 6 months Interventions for managing oral submucous fibrosis (2024) · Cochrane | MD -51.02 [-72.85, -29.20] | 2 studies · 85 participants | Very low |
Facemask with rapid maxillary expansion (RME) vs Pushing Splints Adverse effects · Children and adolescents (aged 16 years or younger) with prominent lower front teeth (Class III malocclusion) · End of treatment Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children (2024) · Cochrane | Galeotti 2021: occasional skin irritation on the chin and three appliance breakages (one facemask, two Pushing Splints). | 1 study · 42 participants | Ungraded |
Not applicable (single-group prevalence) vs Not applicable (single-group prevalence) Dental caries, prevalence · Primary school children in Ethiopia · Sampling technique: simple random sampling Prevalence of dental caries and associated factors among primary school children in Ethiopia: systematic… (2024) | Prevalence 42 [35, 49] | 4 studies · 1421 participants | Ungraded |
Full pulpotomy vs Partial pulpotomy Overall success (composite of clinical and radiographic success) · Mature permanent teeth with symptomatic irreversible pulpitis and carious pulp exposure · >=12 months Efficacy of pulpotomy for permanent teeth with carious pulp exposure: A systematic review and meta-analysis… (2024) | OR 2.16 [0.92, 5.07] | 3 studies | Ungraded |
Silver diamine fluoride (SDF) vs Sealants or resin infiltration Primary caries prevention · Children and adults (with or without carious lesions) · Primary dentition Topical silver diamine fluoride (SDF) for preventing and managing dental caries in children and adults (2024) · Cochrane | No studies reported data in this dentition type | 0 studies | No studies |
Unilateral extraction of the mandibular first permanent molar vs Bilateral extraction of the mandibular first permanent molars Midline deviation of the mandibular arch · Children and adolescents after extraction of a mandibular permanent first molar (before eruption of the second molar) · Until eruption of the permanent second molar (median follow-up 4.0 years), Mandible Spontaneous space closure after extraction of permanent first molars in children and adolescents: a… (2024) | OR 11.6 [1.9, 70.3] | 1 study | Ungraded |
Topical curcumin gel vs Topical aloe vera gel Burning sensation (VAS 0-100) · People of any age with a confirmed diagnosis, by clinical examination and biopsy, of oral submucous fibrosis (OSF) · Less than 3 months Interventions for managing oral submucous fibrosis (2024) · Cochrane | MD 16.00 [7.21, 24.79] | 1 study · 60 participants | Very low |
Consumption of xylitol chewing gum by women (mothers) vs Consumption of CHX/xylitol gum by women, or CHX varnish applied to women's dentition defs index score (categories) · For interventions, pregnant women and mothers of infants in the first year of life; for outcomes, children up to 6… Interventions with pregnant women, new mothers and other primary caregivers for preventing early childhood… (2024) · Cochrane | Thorild 2003 defs score categories (very low-certainty): 1-3 defs RR 0.48 (95% CI 0.15 to 1.54); 3-4 defs RR 0.85 (95% CI 0.18 to 3.98); >=5 defs RR 0.28 (95% CI 0.01 to 6.78); 96 participants. | 1 study · 96 participants | Very low |
Facemask (RME) or modified facemask vs Surgically-anchored appliance (miniscrews or miniplates) Wits appraisal · Children and adolescents (aged 16 years or younger) with prominent lower front teeth (Class III malocclusion) · End of treatment Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children (2024) · Cochrane | MD 0.50 [-1.27, 2.27] | 1 study · 43 participants | Ungraded |
Facemask with rapid maxillary expansion (RME) vs Pushing Splints Overjet · Children and adolescents (aged 16 years or younger) with prominent lower front teeth (Class III malocclusion) · End of treatment Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children (2024) · Cochrane | MD 0.80 [-0.37, 1.97] | 1 study · 42 participants | Ungraded |
Not applicable (single-group prevalence) vs Not applicable (single-group prevalence) Early childhood caries (ECC) prevalence (%, dmft>0) · Children younger than 71 months (under 6 years) · Life expectancy: 71-75 years A systematic review and meta-analysis on early-childhood-caries global data. (2024) | Prevalence 62 | NR | Ungraded |
Vasodilators (isoxsuprine, xanthinol nicotinate) vs Placebo or no active treatment Adverse effects · People of any age with a confirmed diagnosis, by clinical examination and biopsy, of oral submucous fibrosis (OSF) Interventions for managing oral submucous fibrosis (2024) · Cochrane | Adverse effects (any): 0 placebo vs 14 minor (transient flushing and upper trunk warmness); 85 (2); no GRADE rating. | 2 studies · 85 participants | Ungraded |
Mineral trioxide aggregate (MTA) vs Calcium hydroxide (CH) Overall success (composite of clinical and radiographic success) · Permanent teeth with carious pulp exposure · >=12 months, Partial pulpotomy Efficacy of pulpotomy for permanent teeth with carious pulp exposure: A systematic review and meta-analysis… (2024) | OR 2.81 [1.38, 5.74] | NR | Ungraded |
Maternal smoking during pregnancy vs No maternal smoking during pregnancy Dental caries in children · Children of mothers assessed for smoking status during pregnancy (early childhood dental caries) · Exposure during pregnancy; caries assessed in early childhood, Overall (all 12 studies pooled) Maternal smoking during pregnancy and early childhood dental caries in children: a systematic review and… (2024) | OR 1.774 [1.554, 2.026] | 12 studies · 90405 participants | Ungraded |
Adjunctive antimicrobial photodynamic therapy (aPDT) applied after subgingival instrumentation (SI) vs Subgingival instrumentation (SI) alone (hand or power-driven, or both), or SI plus placebo/sham aPDT Change in bleeding on probing (BOP) · Adults (> 18 years) with recurrent periodontitis, receiving supportive (maintenance) periodontal care · 3 months (change from baseline) Adjunctive antimicrobial photodynamic therapy for treating periodontal and peri‐implant diseases (2024) · Cochrane | MD 2.38 [-1.34, 6.10] | 5 studies · 231 participants | Ungraded |
Antioxidants (lycopene, curcumin, Oxitard) vs Placebo or no active treatment Intolerance to spicy food (participant-reported proxy) · People of any age with a confirmed diagnosis, by clinical examination and biopsy, of oral submucous fibrosis (OSF) Interventions for managing oral submucous fibrosis (2024) · Cochrane | OR 0.02 [0.00, 0.43] | 1 study · 100 participants | Ungraded |
Probiotics (any strain, dose, or presentation), minimum intake duration 0.2 months vs No treatment or placebo (control) Gingival index · Children and/or adolescents (<18 years) without background systemic disease · follow-up: mean 3.07 months, Overall (all presentations pooled) Efficacy of Probiotic Consumption on Oral Outcomes in Children and/or Adolescents: A Meta-Analysis. (2024) | MD 0.04 [-0.18, 0.27] | 3 studies · 144 participants | Low |
Grape seed extract or grape seed flavonoid fractions vs No extract or vehicle control; other antimicrobial agents Bacterial growth inhibition · Streptococcus mutans cultures and biofilms Effect of flavonoids from grape seed and cranberry extracts on the microbiological activity of Streptococcus… (2024) | no estimate extracted | 5 studies | Ungraded |
Occlusal splint vs No treatment or placebo (non-occlusal or transparent-foil placebo splint) Muscle pain when chewing · People with temporomandibular disorders (TMD) · Short term (3 months), Disc displacement without reduction (DDwoR) Occlusal interventions for managing temporomandibular disorders (2024) · Cochrane | MD -1.97 [-2.37, -1.57] | 1 study · 84 participants | Very low |
Postoperative systemic antibiotics (phenoxymethylpenicillin/penicillin VK, 7-day course), partial or total chemo-mechanical debridement and analgesics vs Matched placebo, partial or total chemo-mechanical debridement and analgesics Pain at 72 hours · Adults with a symptomatic necrotic tooth or localised acute apical abscess (no signs of spreading infection or… · 72 hours Systemic antibiotics for symptomatic apical periodontitis and acute apical abscess in adults (2024) · Cochrane | MD 0.08 [-0.38, 0.54] | 2 studies · 61 participants | Very low |
Facemask vs Untreated control (no treatment) Self-esteem (Oral Aesthetic Subjective Impact Score, OASIS) · Children and adolescents (aged 16 years or younger) with prominent lower front teeth (Class III malocclusion) · End of treatment Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children (2024) · Cochrane | MD -4.00 [-7.40, -0.60] | 1 study · 69 participants | Ungraded |
Fixed orthodontic treatment with fixed (multibracket) appliances (exposure) vs None (single-group prevalence/incidence estimate) Association between patient age and number of ICLs · Patients (permanent dentition) during or after fixed orthodontic treatment with fixed (multibracket) appliances · During or after fixed orthodontic treatment, By patient age (subgroup meta-analysis; no significant association) Distribution of initial caries lesions in relation to fixed orthodontic therapy. A systematic review and… (2024) | No significant association found between patient age and the number of ICLs (meta-regression / subgroup analysis) | NR | Ungraded |
Absence of toothpaste use vs Toothpaste use Dental caries · Primary school children in Ethiopia Prevalence of dental caries and associated factors among primary school children in Ethiopia: systematic… (2024) | OR 1.42 [-1.278, 4.109] | NR | Ungraded |
Adjunctive antimicrobial photodynamic therapy (aPDT) applied after subgingival instrumentation (SI) vs Subgingival instrumentation (SI) alone (hand or power-driven, or both), or SI plus placebo/sham aPDT Change in bleeding on probing (BOP) · Adults (> 18 years) with a clinical diagnosis of periodontitis, receiving active (non-surgical anti-infective) treatment · 6 months (change from baseline) Adjunctive antimicrobial photodynamic therapy for treating periodontal and peri‐implant diseases (2024) · Cochrane | MD 5.72 [1.62, 9.81] | 5 studies · 171 participants | Very low |
Reduction in previous year's academic score vs No reduction in academic score Reduction in previous year's academic score · Primary school children in Ethiopia Prevalence of dental caries and associated factors among primary school children in Ethiopia: systematic… (2024) | OR 5.51 [1.952, 9.066] | NR | Ungraded |
Facemask vs Untreated control (no treatment) ANB · Children and adolescents (aged 16 years or younger) with prominent lower front teeth (Class III malocclusion) · 6-year follow-up Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children (2024) · Cochrane | MD 0.70 [-0.74, 2.14] | 1 study · 65 participants | Low |
Occlusal splint vs Acupuncture Discomfort · People with temporomandibular disorders (TMD) Occlusal interventions for managing temporomandibular disorders (2024) · Cochrane | Listed in Summary of findings 5 as 'Not reported'; this outcome was not reported by any included study for this comparison. | 0 studies | No studies |
Second molar at Demirjian stage F-G at extraction vs Second molar at Demirjian stage D-E at extraction Spontaneous space closure · Children and adolescents after extraction of a mandibular permanent first molar (before eruption of the second molar) · Until eruption of the permanent second molar (median follow-up 4.0 years), Mandible Spontaneous space closure after extraction of permanent first molars in children and adolescents: a… (2024) | OR 0.68 [0.28, 1.66] | 4 studies | Ungraded |
Superelastic NiTi arch wire vs Conventional (stabilised) NiTi arch wire Pain day 1 · People receiving orthodontic treatment with fixed appliances (upper and/or lower full arch) · 3 to 7 days Initial arch wires used in orthodontic treatment with fixed appliances (2024) · Cochrane | MD 0.29 [-0.52, 1.10] | 2 studies · 142 participants | Low |
Occlusal splint vs Pharmacological therapy Muscle pain at mastication · People with temporomandibular disorders (TMD) Occlusal interventions for managing temporomandibular disorders (2024) · Cochrane | Listed in Summary of findings 6 as 'Not reported'; this outcome was not reported by any included study for this comparison. | 0 studies | No studies |
Occlusal splint vs Another occlusal splint with a different mechanism of action Joint pain at rest · People with temporomandibular disorders (TMD) · Long term (12 months), Disc displacement with reduction (DDwR) Occlusal interventions for managing temporomandibular disorders (2024) · Cochrane | RR 7.00 [0.41, 120.16] | 1 study · 20 participants | Very low |
Intervention NR Overall success (composite of clinical and radiographic success) · Partial pulpotomy, mature teeth Efficacy of pulpotomy for permanent teeth with carious pulp exposure: A systematic review and meta-analysis… (2024) | Proportion 0.842 [0.745, 0.921] | 6 studies | Ungraded |
Superelastic NiTi arch wire vs Thermoelastic NiTi arch wire Time to alignment · People receiving orthodontic treatment with fixed appliances (upper and/or lower full arch) · 16 weeks Initial arch wires used in orthodontic treatment with fixed appliances (2024) · Cochrane | MD 0.5 [0.21, 0.79] | 1 study · 32 participants | Low |
TT+CC (homozygous) genotypes vs TC (heterozygous) genotype Dental caries · Children (<18 years) with vs without dental caries · Over-dominant model (TT+CC vs TC), Real-time quantitative PCR genotyping Association of vitamin D receptor gene polymorphisms with caries risk in children: a systematic review and… (2024) | OR 1.52 [1.10, 2.10] | NR | Ungraded |
Chin cup vs Untreated control (no treatment) ANB · Children and adolescents (aged 16 years or younger) with prominent lower front teeth (Class III malocclusion) · End of treatment Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children (2024) · Cochrane | MD 1.96 [1.58, 2.34] | 1 study · 50 participants | Ungraded |
Bone-anchored intermaxillary traction (BAIMT) vs Removable mandibular retractor (RMR) Adverse effects / patient-reported (pain, self-confidence) · Children and adolescents (aged 16 years or younger) with prominent lower front teeth (Class III malocclusion) · During treatment Orthodontic treatment for prominent lower front teeth (Class III malocclusion) in children (2024) · Cochrane | Majanni 2016: BAIMT associated with higher pain early in treatment than RMR (P<0.001); RMR negatively impacted self-confidence more than BAIMT at all time points (P<0.001). | 1 study · 38 participants | Ungraded |