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. Words match anywhere in the field.
15,213 questions in 2,394 reviews
current versionsNo studies 15,213 · 100%Ungraded 0 · 0%Very low 0 · 0%Low 0 · 0%Moderate 0 · 0%High 0 · 0%
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 |
|---|---|---|---|
Summary of findings: Vitamin C supplementation vs placebo Adverse events · adults and children with exercise‐induced bronchoconstriction/asthma Vitamin C for asthma and exercise‐induced bronchoconstriction (2013) · Cochrane | no estimate extracted | NR | No studies |
Summary of findings: Vitamin C supplementation vs placebo Health‐related quality of life (HRQL) · adults and children with exercise‐induced bronchoconstriction/asthma Vitamin C for asthma and exercise‐induced bronchoconstriction (2013) · Cochrane | no estimate extracted | NR | No studies |
Summary of findings: Vitamin C supplementation vs placebo Asthma exacerbations · adults and children with exercise‐induced bronchoconstriction/asthma Vitamin C for asthma and exercise‐induced bronchoconstriction (2013) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Health Service Utilisation · Pharmacies or pharmacists delivering services in outpatient settings and asthmatic patients The effect of pharmacist‐provided non‐dispensing services on patient outcomes, health service utilisation… (2013) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Cost · Pharmacies or pharmacists delivering services in outpatient settings and asthmatic patients The effect of pharmacist‐provided non‐dispensing services on patient outcomes, health service utilisation… (2013) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Number of participant withdrawals due to adverse events ‐ not measured · patients with acute gout Lifestyle interventions for acute gout (2013) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Joint function ‐ not measured · patients with acute gout Lifestyle interventions for acute gout (2013) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Health‐related quality of life ‐ not measured · patients with acute gout Lifestyle interventions for acute gout (2013) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Patient global assessment ‐ not measured · patients with acute gout Lifestyle interventions for acute gout (2013) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Serious adverse events ‐ not measured · patients with acute gout Lifestyle interventions for acute gout (2013) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Adverse events Participants (n) withdrew due to adverse effects · patients with osteoarthritis of the knee Topical herbal therapies for treating osteoarthritis (2013) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Adverse events Participants (n) reported serious adverse events · patients with osteoarthritis of the knee Topical herbal therapies for treating osteoarthritis (2013) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Quality of Life · patients with osteoarthritis of the knee Topical herbal therapies for treating osteoarthritis (2013) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Adverse events Participants (n) withdrew due to adverse effects · patients with osteoarthritis of the knee Topical herbal therapies for treating osteoarthritis (2013) · Cochrane | no estimate extracted | NR | No studies |
Intervention NR Adverse events Participants (n) reported serious adverse events · patients with osteoarthritis of the knee Topical herbal therapies for treating osteoarthritis (2013) · Cochrane | no estimate extracted | NR | No studies |
Arnica vs ibuprofen Adverse events Participants (n) withdrew due to adverse effects · patients with osteoarthritis of the hand Topical herbal therapies for treating osteoarthritis (2013) · Cochrane | no estimate extracted | NR | No studies |
Arnica vs ibuprofen Adverse events Participants (n) reported serious adverse events · patients with osteoarthritis of the hand Topical herbal therapies for treating osteoarthritis (2013) · Cochrane | no estimate extracted | NR | No studies |
Arnica vs ibuprofen Quality of life · patients with osteoarthritis of the hand Topical herbal therapies for treating osteoarthritis (2013) · Cochrane | no estimate extracted | NR | No studies |
Resistance training vs aerobic training Adverse effects · Individuals with fibromyalgia. Resistance exercise training for fibromyalgia (2013) · Cochrane | no estimate extracted | NR | No studies |
Resistance training vs control Adverse effects · Individuals with fibromyalgia. Resistance exercise training for fibromyalgia (2013) · Cochrane | no estimate extracted | NR | No studies |
Interdental brushing plus toothbrushing vs Toothbrushing alone Interproximal caries · Dentate adults aged 16 years and older Interdental brushing for the prevention and control of periodontal diseases and dental caries in adults (2013) · Cochrane | Not estimable. No included study assessed caries as an outcome. (See comment) | 0 studies | No studies |
Resin composite restorations (filling and bonding systems) containing antibacterial agents vs Composite restorations not containing antibacterial agents Postoperative sensitivity, marginal adaptation, anatomic form and other clinical outcomes (USPHS restoration quality; includes tooth vitality and pulpitis) · Adults and adolescents in any age group with restorations in the permanent dentition and children with restorations in… Antibacterial agents in composite restorations for the prevention of dental caries (2013) · Cochrane | No studies were included in this review, as we were unable to find any trials directly comparing antibacterial containing composites to other active interventions or controls. | 0 studies | No studies |
Pre-radiotherapy extraction of diseased molar teeth vs Conservative treatment (restoration of the teeth and leaving them in place during radiotherapy, with oral health education and disease prevention: oral hygiene, fluoride, diet advice) Patients' quality of life · Patients diagnosed with head and neck cancer planned to undergo any type of radiotherapy (external beam, intensity… Dental extractions prior to radiotherapy to the jaws for reducing post‐radiotherapy dental complications (2013) · Cochrane | no estimate extracted | 0 studies | No studies |
Zygomatic implants without bone grafts (as a complete alternative to any bone augmentation procedure) vs Conventional dental implants in augmented maxillae Implant failure (mobile implants, removal of stable implants due to progressive marginal bone loss or infection, implant fractures) · Participants with an atrophic maxilla who cannot be rehabilitated with conventional dental implants due to lack of… · At least 1 year in function Interventions for replacing missing teeth: dental implants in zygomatic bone for the rehabilitation of the… (2013) · Cochrane | Results (Effects of interventions): we could not identify any eligible randomised controlled trials (RCTs). | 0 studies | No studies |
Self etching primers (one-step etchant and primer system) vs Conventional etchants (two-step etch and prime method using 37% phosphoric acid) Participant satisfaction · Children and adults with fixed orthodontic brackets bonded to incisors, canines and premolars Enamel etching for bonding fixed orthodontic braces (2013) · Cochrane | Participant satisfaction: No studies assessed this outcome. | NR | No studies |
Brush biopsy (oral cytology) vs No screening Outcome NR · Planned population: general population or high-risk / opportunistic screening groups (no eligible study) Screening programmes for the early detection and prevention of oral cancer (2013) · Cochrane | There was no evidence to support the use of adjunctive technologies like toluidine blue, brush biopsy or fluorescence imaging as a screening tool to reduce oral cancer mortality; no eligible randomised controlled trial… | 0 studies | No studies |
Dental repositioning vs Spontaneous re-eruption, orthodontic repositioning, or surgical repositioning Outcome NR · Patients (mainly children and young adults) with a history of dental trauma and a diagnosis of luxation (intrusion,… · Minimum 12 months follow-up Interventions for treating traumatised permanent front teeth: luxated (dislodged) teeth (2013) · Cochrane | Types of dental repositioning: to compare spontaneous re-eruption, orthodontic repositioning or surgical repositioning. Main results: No randomised or quasi-randomised controlled trials were found; no study was… | 0 studies | No studies |
Pre-radiotherapy extraction of diseased molar teeth vs Conservative treatment (restoration of the teeth and leaving them in place during radiotherapy, with oral health education and disease prevention: oral hygiene, fluoride, diet advice) Overall survival · Patients diagnosed with head and neck cancer planned to undergo any type of radiotherapy (external beam, intensity… Dental extractions prior to radiotherapy to the jaws for reducing post‐radiotherapy dental complications (2013) · Cochrane | no estimate extracted | 0 studies | No studies |
Pre-radiotherapy extraction of healthy molar teeth vs Conservative treatment (leaving the teeth in place during radiotherapy, with oral health education and disease prevention: oral hygiene, fluoride, diet advice) Delay in start of radiation treatment · Patients diagnosed with head and neck cancer planned to undergo any type of radiotherapy (external beam, intensity… Dental extractions prior to radiotherapy to the jaws for reducing post‐radiotherapy dental complications (2013) · Cochrane | no estimate extracted | 0 studies | No studies |
Acupuncture vs Placebo (sham acupuncture) Patient satisfaction with treatment · Adults with dry mouth due to radiotherapy (head and neck cancer) or Sjogren's Syndrome Interventions for the management of dry mouth: non‐pharmacological interventions (2013) · Cochrane | no estimate extracted | 0 studies | No studies |
Any intervention to manage relapse: fixed options (labial braces, lingual braces, fixed lingual wire) or removable options (Hawley's retainer with spring elastomeric module, Bloore removable aligner, other Hawley's retainer modifications, Invisalign, Clearstep) vs Another such intervention or no active treatment; all interventions compared against each other in any combination Aesthetic assessment by participants and practitioners · Participants who previously underwent orthodontic treatment, with subsequent crowding (relapse) of the lower front… Interventions for managing relapse of the lower front teeth after orthodontic treatment (2013) · Cochrane | No RCTs met the inclusion criteria for this review. After deduplication, the electronic searching identified 527 publications; after reviewing the titles and abstracts, none focused on interventions to correct the… | 0 studies | No studies |
Intraoral distalising appliance vs Headgear (extraoral appliance) Number of attendances required to complete treatment · Children and adolescents (aged 16 years or less at the start of treatment) undergoing orthodontic treatment to… Orthodontic treatment for distalising upper first molars in children and adolescents (2013) · Cochrane | Number of attendances required to complete treatment was not reported by these studies. | 0 studies | No studies |
Pre-radiotherapy extraction of healthy molar teeth vs Conservative treatment (leaving the teeth in place during radiotherapy, with oral health education and disease prevention: oral hygiene, fluoride, diet advice) Development of post-radiotherapy dental complications (caries, fractured teeth, periapical infection, periodontal disease, osteoradionecrosis) · Patients diagnosed with head and neck cancer planned to undergo any type of radiotherapy (external beam, intensity… Dental extractions prior to radiotherapy to the jaws for reducing post‐radiotherapy dental complications (2013) · Cochrane | no estimate extracted | 0 studies | No studies |
Zygomatic implants for retaining a maxillary obturator vs Non-implant retained obturators, local and regional flaps, or microvascular free flaps Outcome NR · Patients requiring maxillary reconstruction after partial or total maxillectomy (cancer patients) · At least 1 year in function Interventions for replacing missing teeth: dental implants in zygomatic bone for the rehabilitation of the… (2013) · Cochrane | Results (Effects of interventions): we could not identify any eligible randomised controlled trials (RCTs). | 0 studies | No studies |
Root canal medicaments vs No medicaments, placebo, or a different type of medicament Outcome NR · Patients (mainly children and young adults) with a history of dental trauma and a diagnosis of luxation (intrusion,… · Minimum 12 months follow-up Interventions for treating traumatised permanent front teeth: luxated (dislodged) teeth (2013) · Cochrane | Types of root canal medicaments: this was compared with no medicaments, placebo and different types of medicaments. Main results: No randomised or quasi-randomised controlled trials were found; no study was included in… | 0 studies | No studies |
Electrostimulation (device) vs Placebo (sham/placebo device) Duration of effectiveness · Adults with dry mouth due to Sjogren's Syndrome Interventions for the management of dry mouth: non‐pharmacological interventions (2013) · Cochrane | no estimate extracted | 0 studies | No studies |
Interdental brushing plus toothbrushing vs Toothbrushing alone Periodontitis (clinical attachment loss) · Dentate adults aged 16 years and older Interdental brushing for the prevention and control of periodontal diseases and dental caries in adults (2013) · Cochrane | Not estimable. No included study assessed periodontitis as an outcome. (See comment) | 0 studies | No studies |
Orthodontic distalising appliance (intraoral or extraoral) vs Untreated control (no treatment) Adverse effects (headgear injuries, gum health, tooth damage/decay, root resorption) · Children and adolescents (aged 16 years or less at the start of treatment) undergoing orthodontic treatment to… Orthodontic treatment for distalising upper first molars in children and adolescents (2013) · Cochrane | Adverse effects were not reported in the studies of this comparison; no included study across the review reported adverse effects, harm or injury. | 0 studies | No studies |
Fluorescence imaging / light-based techniques vs No screening Outcome NR · Planned population: general population or high-risk / opportunistic screening groups (no eligible study) Screening programmes for the early detection and prevention of oral cancer (2013) · Cochrane | There was no evidence to support the use of adjunctive technologies like toluidine blue, brush biopsy or fluorescence imaging as a screening tool to reduce oral cancer mortality; no eligible randomised controlled trial… | 0 studies | No studies |
Hyperbaric oxygen (HBO) therapy vs No HBO therapy Cost effectiveness · Patients who have had radiotherapy and who have missing teeth that require replacement with osseointegrated dental… Interventions for replacing missing teeth: hyperbaric oxygen therapy for irradiated patients who require… (2013) · Cochrane | Cost effectiveness data were not presented but it was possible to extrapolate this. | 0 studies | No studies |
Resin composite restorations (filling and bonding systems) containing antibacterial agents vs Composite restorations not containing antibacterial agents Longevity of restorations (time to failure in months) · Adults and adolescents in any age group with restorations in the permanent dentition and children with restorations in… Antibacterial agents in composite restorations for the prevention of dental caries (2013) · Cochrane | No studies were included in this review, as we were unable to find any trials directly comparing antibacterial containing composites to other active interventions or controls. | 0 studies | No studies |
Fixation (splinting) vs No splint, or a different type or duration of splint Outcome NR · Patients (mainly children and young adults) with a history of dental trauma and a diagnosis of luxation (intrusion,… · Minimum 12 months follow-up Interventions for treating traumatised permanent front teeth: luxated (dislodged) teeth (2013) · Cochrane | Types and duration of fixation: the effect of using no splint or different types of splints and their duration. Main results: No randomised or quasi-randomised controlled trials were found; no study was included in… | 0 studies | No studies |
Interdental brushing plus toothbrushing vs Flossing plus toothbrushing Periodontitis (clinical attachment loss) · Dentate adults aged 16 years and older Interdental brushing for the prevention and control of periodontal diseases and dental caries in adults (2013) · Cochrane | Not estimable. No included study assessed clinical attachment loss, a measure of progression of periodontitis. (See comment) | 0 studies | No studies |
Any intervention to manage relapse: fixed options (labial braces, lingual braces, fixed lingual wire) or removable options (Hawley's retainer with spring elastomeric module, Bloore removable aligner, other Hawley's retainer modifications, Invisalign, Clearstep) vs Another such intervention or no active treatment; all interventions compared against each other in any combination Assessment of the alignment of the lower front teeth using any method or index · Participants who previously underwent orthodontic treatment, with subsequent crowding (relapse) of the lower front… Interventions for managing relapse of the lower front teeth after orthodontic treatment (2013) · Cochrane | No RCTs met the inclusion criteria for this review. After deduplication, the electronic searching identified 527 publications; after reviewing the titles and abstracts, none focused on interventions to correct the… | 0 studies | No studies |
Sodium hypochlorite 1.3% with MTAD final rinse vs Sodium hypochlorite 1.3% with normal saline final rinse Adverse effects · Patients aged 14 to 78 years with mature permanent teeth (fully formed roots), single or multi-rooted, with pulpal or… Irrigants for non‐surgical root canal treatment in mature permanent teeth (2012) · Cochrane | no estimate extracted | 0 studies | No studies |
Sodium hypochlorite 5.25% with EDTA 17% vs Sodium hypochlorite 1.3% with MTAD Mean change in health-related quality of life or participant-expressed satisfaction with the procedure · Patients aged 14 to 78 years with mature permanent teeth (fully formed roots), single or multi-rooted, with pulpal or… Irrigants for non‐surgical root canal treatment in mature permanent teeth (2012) · Cochrane | no estimate extracted | 0 studies | No studies |
Sodium hypochlorite 5.25% with EDTA 17% vs Sodium hypochlorite 1.3% with MTAD Adverse effects · Patients aged 14 to 78 years with mature permanent teeth (fully formed roots), single or multi-rooted, with pulpal or… Irrigants for non‐surgical root canal treatment in mature permanent teeth (2012) · Cochrane | no estimate extracted | 0 studies | No studies |
HAART regimen + topical treatment vs HAART regimen alone Adverse effects of long‐term use of available topical agents · HIV‐infected adults (> 13 years of age, per CDC) with one or more painful intraoral aphthous ulcers Topical treatments for HIV‐related oral ulcers (2012) · Cochrane | No studies were included in this review. A total of 233 abstracts were retrieved; 25 were selected as potentially eligible but all were excluded (10 reported systemic rather than topical treatment; 3 non‐RCTs; 6… | 0 studies | No studies |
Non-surgical interventions vs Surgical interventions Outcome NR · People with at least one dental implant affected by peri-implantitis Interventions for replacing missing teeth: treatment of peri‐implantitis (2012) · Cochrane | Non-surgical versus surgical interventions: no trials. | 0 studies | No studies |
Sodium hypochlorite 5% (also 2.5%) vs Sodium hypochlorite 1% Change in periapical radiolucency (radiography or CBCT), up to 1 year after treatment · Patients aged 14 to 78 years with mature permanent teeth (fully formed roots), single or multi-rooted, with pulpal or… Irrigants for non‐surgical root canal treatment in mature permanent teeth (2012) · Cochrane | no estimate extracted | 0 studies | No studies |