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.
5,762 questions in 263 reviews · Dental caries
current versionsNo studies 321 · 5.6%Ungraded 4,450 · 77.2%Very low 455 · 7.9%Low 297 · 5.2%Moderate 200 · 3.5%High 39 · 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 |
|---|---|---|---|
Fluoride mouthwash (e.g., NaF / amine fluoride) vs Blank control (no mouthwash; before-after comparison) Gingival inflammation-related index · Orthodontic patients (any age) undergoing orthodontic treatment (mostly fixed appliances) · <=3 months (short-term) The efficacy of mouthwashes on oral microorganisms and gingivitis in patients undergoing orthodontic… (2023) | MGI' and BI' was significantly reduced compared to baseline [34]. BOP and GI was slightly lower compared to blank control [46]. | 2 studies | Very low |
Root carious dentin vs Coronal carious dentin MMP-2 presence/activity · Human ex vivo carious dentin (coronal and root) Presence of host and bacterial-derived collagenolytic proteases in carious dentin: a systematic review of ex… (2023) | There is no difference in MMP-2 activity in root vs. coronal carious dentin; MMP-2 was present in both coronal and root dentin in all specimens (Toledano et al., 2010). The evidence is very uncertain. | 1 study · 10 participants | Very low |
Resin infiltration vs CPP-ACP Remineralization / reduction in lesion severity (change in QLF, laser fluorescence, or lesion area) · Patients with white spot lesions / early caries lesions (WSLs/ECLs), including orthodontic and non-orthodontic… Comparison of therapies of white spot lesions: a systematic review and network meta-analysis. (2023) | SMD -0.77 [-1.31, -0.23] | 1 study | Ungraded |
Multivariable caries prediction model vs Additional prediction model(s) Coronal caries increment · Individuals of all ages · Follow-up ≥1 year, Pang,2021 [19]; model performance 1 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR− 0.80 [0.71, 0.89] | 1 study | Ungraded |
Periodontal disease (severe periodontitis) vs Absence of periodontal disease Oral health-related quality of life (OHRQoL) · Adolescents (10-19 years) Oral-health-related quality of life in adolescents: umbrella review. (2023) | individuals with severe periodontitis had worse OHRQoL scores [9]. | NR | Ungraded |
Multivariable caries prediction model vs Additional prediction model(s) Coronal caries increment · Individuals of all ages · Follow-up ≥1 year, Gao,2013 [29]; model performance 12 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR− 0.14 [0.08, 0.26] | 1 study | Ungraded |
Multivariable caries prediction model vs Additional prediction model(s) Coronal caries increment · Individuals of all ages · Follow-up ≥1 year, Fontana,2011 [16]; model performance 8 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR− 0.44 [0.35, 0.56] | 1 study | Ungraded |
Baseline caries vs Lower baseline caries Change in height-for-age z score · Preschool children · Mean follow-up 9.73 months, Unadjusted model The bi-directional relationship between growth stunting and early childhood caries: a rapid review. (2023) | coefficient -0.03 [-0.04, 0.01] | 1 study · 1111 participants | Ungraded |
Periodontal disease assessed by Community Periodontal Index (CPI) vs Individuals without periodontal disease (by CPI) Oral health-related quality of life (dichotomous: poor vs not) · Indian adults and elderly (general, police, teachers, institutionalised) Impact of oral conditions on oral health-related quality of life among Indians- a systematic review and… (2023) | Periodontal disease (CPI) vs none: studies show inconsistency; two studies showed poor QoL (Nagarajappa 2015, Saxena 2018), one no significant association (Shivakumar 2018); 1345 participants, 3 observational studies;… | 3 studies · 1345 participants | Very low |
Supraomohyoid neck dissection vs Modified radical neck dissection Locoregional recurrence · Adults with oral cavity or oropharyngeal cancer Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment (2023) · Cochrane | Locoregional recurrence: reported but not usable (variable follow-up) (Guo 2014). | 1 study | Ungraded |
Gingivitis (assessed by gingival index or WHO criteria) vs Individuals without gingivitis Oral health-related quality of life (continuous), measured by GOHAI / OHIP-14 · Indians (adolescents, adults, elderly, children) Impact of oral conditions on oral health-related quality of life among Indians- a systematic review and… (2023) | Gingivitis and QoL (continuous): GOHAI - one study found poorer QoL (Appukuttan 2016, P<0.05), one no significant association (Marya 2020, P=0.08); OHIP-14 - no impact (Sreela 2020, P=0.0762). Not pooled. | 3 studies | Ungraded |
Fluoride mouthwash vs Blank control Plaque-related index · Orthodontic patients · ≥ 12 months The efficacy of mouthwashes on oral microorganisms and gingivitis in patients undergoing orthodontic… (2023) | PI was similar to blank control [37]; API was slightly reduced compared to blank control and significant at 6 and 9 months [59]. | 2 studies | Very low |
Multivariable caries prediction model vs Additional prediction model(s) Coronal caries increment · Individuals of all ages · Follow-up ≥1 year, Birpou,2019 [25]; model performance 4 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR− 0.58 [0.40, 0.84] | 1 study | Ungraded |
Mineral trioxide aggregate (MTA) vs Calcium hydroxide (CH) Clinical and radiographic success · Patients with carious pulp exposure in immature permanent teeth · 1 to 2 years, Immature teeth Comparative efficacy of materials used in patients undergoing pulpotomy or direct pulp capping in carious… (2023) | OR 2.22 [0.13, 36.67] | 2 studies · 106 participants | Very low |
Multivariable caries prediction model vs Additional prediction model(s) Coronal caries increment · Individuals of all ages · Follow-up ≥1 year, Gao,2013 [29]; model performance 1 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR+ 5.31 [4.01, 7.03] | 1 study | Ungraded |
Indirect restorations (crowns, fixed partial dentures, inlays/onlays/veneers) vs None (single-group incidence) Periapical pathosis · Vital teeth restored with indirect restorations · >5-10 years, Follow-up >5-10 years Incidence and influential factors in pulp necrosis and periapical pathosis following indirect restorations:… (2023) | Proportion 3.88 [1.95, 6.45] | 1864 participants | Ungraded |
Multivariable caries prediction model vs Additional prediction model(s) Coronal caries increment · Individuals of all ages · Follow-up ≥1 year, Beck,1992 [24]; model performance 3 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR+ 1.83 [1.62, 2.06] | 1 study | Ungraded |
Resin infiltration vs Control (placebo / no active therapy) Remineralization / reduction in lesion severity (change in QLF, laser fluorescence, or lesion area) · Patients with white spot lesions / early caries lesions (WSLs/ECLs), including orthodontic and non-orthodontic… Comparison of therapies of white spot lesions: a systematic review and network meta-analysis. (2023) | SMD -0.94 [-1.46, -0.43] | 1 study | Ungraded |
Vitamin D deficiency (serum 25(OH)D < 50 nmol/L) vs Normal vitamin D level (serum 25(OH)D ≥ 50 nmol/L) Dental caries · Children (<19 years) · Cross-sectional studies Correlation between vitamin D levels in serum and the risk of dental caries in children: a systematic review… (2023) | RR 1.19 [1.14, 1.24] | 5 studies | Ungraded |
Dentin caries vs Enamel caries Bacterial collagenolytic-protease gene expression · Coronal dentin and enamel caries samples Presence of host and bacterial-derived collagenolytic proteases in carious dentin: a systematic review of ex… (2023) | no estimate extracted | 1 study | Ungraded |
Surgery vs Radiotherapy alone Total mortality · Adults with oropharyngeal cancer · 3 years Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment (2023) · Cochrane | HR 0.83 [0.09, 7.46] | 1 study · 68 participants | Low |
Multivariable caries prediction model vs Additional prediction model(s) Coronal caries increment · Individuals of all ages · Follow-up ≥1 year, Gao.2010 [17]; model performance 2 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR+ 9.04 [7.41, 11.03] | 1 study | Ungraded |
Multivariable caries prediction model vs Additional prediction model(s) Coronal caries increment · Individuals of all ages · Follow-up ≥1 year, Demers,1992 [14]; model performance 2 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR− 0.40 [0.26, 0.64] | 1 study | Ungraded |
Multivariable caries prediction model vs Additional prediction model(s) Root caries increment · Individuals of all ages · Follow-up ≥1 year, Hayes,2017 [33]; model performance 4 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR− 0.37 [0.23, 0.59] | 1 study | Ungraded |
Periodontal disease assessed by Community Periodontal Index (CPI) vs Individuals without periodontal disease (by CPI) Oral health-related quality of life (continuous), measured by OHIP-14 / OIDP · Indian adults and elderly (general, police, teachers, institutionalised) Impact of oral conditions on oral health-related quality of life among Indians- a systematic review and… (2023) | SMD -0.18 [-0.53, 0.18] | 4 studies · 3064 participants | Very low |
Clear aligners (CA) vs Conventional fixed orthodontic appliances (CF) Plaque accumulation (Plaque Index) · Orthodontic patients undergoing comprehensive treatment (late mixed or permanent dentition, no active caries) · Range 1 to 12 months (maximum time-point per study), Study design: non-randomized studies of interventions White spot lesions, plaque accumulation and salivary caries-associated bacteria in clear aligners compared… (2023) | SMD -1.46 [-2.77, -0.15] | 5 studies · 246 participants | Moderate |
Multivariable caries prediction model vs Additional prediction model(s) Coronal caries increment · Individuals of all ages · Follow-up ≥1 year, Gao.2010 [17]; model performance 3 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR+ 2.15 [1.96, 2.35] | 1 study | Ungraded |
Indirect restorations (crowns, fixed partial dentures, inlays/onlays/veneers) vs None (single-group incidence) Pulp necrosis · Vital teeth restored with indirect restorations · Follow-up ≤5 to >10 years Incidence and influential factors in pulp necrosis and periapical pathosis following indirect restorations:… (2023) | Proportion 5.02 [3.70, 6.52] | 37 studies · 11615 participants | Low |
Dental caries (assessed by DMFT/deft/dmft, WHO criteria or PUFA) vs Individuals without dental caries Oral health-related quality of life (continuous), measured by GOHAI · Indians across all ages (children, adolescents, adults, elderly) Impact of oral conditions on oral health-related quality of life among Indians- a systematic review and… (2023) | Dental caries and QoL (GOHAI): all three studies (Appukuttan 2016, Rekhi 2018, Rekhi 2015) found decayed teeth associated with poorer QoL (P<0.05); not pooled. | 3 studies | Ungraded |
Multivariable caries prediction model vs Additional prediction model(s) Coronal caries increment · Individuals of all ages · Follow-up ≥1 year, Gao.2010 [17]; model performance 3 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR− 0.30 [0.26, 0.36] | 1 study | Ungraded |
Dental caries vs Absence/lower severity of dental caries Oral health-related quality of life (OHRQoL) · Adolescents (10-19 years) Oral-health-related quality of life in adolescents: umbrella review. (2023) | The impact of dental caries on OHRQoL was addressed in five systematic reviews [9, 26, 34, 36, 37]. Three articles report that the greater the severity of the carious lesion, the worse the impact on OHRQoL in… | 5 studies | Ungraded |
Elective neck dissection (at time of primary tumour resection) vs Therapeutic (delayed) neck dissection Recurrence · Adults with oral cavity cancer (tongue or floor of mouth) and clinically negative neck nodes · 3 years Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment (2023) · Cochrane | RR 0.58 [0.48, 0.70] | 3 studies · 633 participants | Moderate |
Female sex vs Male sex Oral health-related quality of life (OHRQoL) · Adolescents (10-19 years) Oral-health-related quality of life in adolescents: umbrella review. (2023) | Worse oral health status, older age, female sex and worse socioeconomic status were significantly associated with worse OHRQoL. [Conclusion: gender and skin color did not have their level of impact clarified.] | NR | Ungraded |
Multivariable prediction model of caries increment (>=3 predictors), e.g. logistic-regression or algorithm-based caries-risk models vs Alternative prediction model(s) within the same study, or no formal comparator (models compared descriptively; no between-model statistical test) Predictive performance for root caries increment (positive likelihood ratio, LR+) · Older adults (aged 52-95; mean 52-73) at risk of root caries increment · Follow-up >=1 year (included studies 1-5 years), Model validation studies Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | No meta-analysis. Only one root-caries validation study (Hayes 2017 [33], 5 Cariogram models); per-model LR+ (Table 2) ranged 1.88-2.78 (best when mutans streptococci omitted). | 1 study | Ungraded |
Multivariable caries prediction model vs Additional prediction model(s) Coronal caries increment · Individuals of all ages · Follow-up ≥1 year, Disney,1992 [15]; model performance 1 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR+ 3.47 [2.89, 4.16] | 1 study | Ungraded |
Carious dentin vs Sound dentin MMP-13 presence/activity · Human ex vivo carious dentin (mostly coronal), natural caries lesions Presence of host and bacterial-derived collagenolytic proteases in carious dentin: a systematic review of ex… (2023) | MMP-13 may be increased in carious dentin when compared to sound dentin, but the evidence is very uncertain (Loreto et al., 2014: more in coronal caries, p<0.05). | 1 study · 13 participants | Very low |
Early childhood caries / severe early childhood caries vs Caries-free children Growth stunting / low linear growth (height-for-age z-score) · Children in early childhood (0-6 years) · Tsang et al. 2019 (Nepal) The bi-directional relationship between growth stunting and early childhood caries: a rapid review. (2023) | The severity of child caries measured by the dmft index correlated with mouth pain and both chronic (stunting) and acute malnutrition (HAZ score) (p<0.0001). | 1 study · 836 participants | Ungraded |
Edentulism (complete or partial missing teeth) vs Individuals without edentulism Oral health-related quality of life (continuous), measured by GOHAI / WHOQoL · Indian elderly Impact of oral conditions on oral health-related quality of life among Indians- a systematic review and… (2023) | Edentulism and QoL (continuous, GOHAI/WHOQoL): one study reported edentulism negatively influenced QoL (Marina 2019), one found no effect (Appukuttan 2016). Not pooled. | 2 studies | Ungraded |
Dental caries (assessed by DMFT/deft/dmft, WHO criteria or PUFA) vs Individuals without dental caries Oral health-related quality of life (continuous), measured by ECOHIS / Michigan Oral Health QoL · Indian children aged 3-5 years · Children 3-5 years (ECOHIS/Michigan, continuous) Impact of oral conditions on oral health-related quality of life among Indians- a systematic review and… (2023) | Subgroup children 3-5 years (continuous, ECOHIS/Michigan): early childhood caries significantly associated with poorer OHRQoL (Singh N 2020, Ghanghas 2019, Jaggi 2019); not pooled. | 3 studies | Ungraded |
Multivariable caries prediction model vs Additional prediction model(s) Coronal caries increment · Individuals of all ages · Follow-up ≥1 year, Demers,1992 [14]; model performance 1 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR− 0.14 [0.07, 0.28] | 1 study | Ungraded |
Fluoride varnish vs CPP-ACP Remineralization / reduction in lesion severity (change in QLF, laser fluorescence, or lesion area) · Patients with white spot lesions / early caries lesions (WSLs/ECLs), including orthodontic and non-orthodontic… Comparison of therapies of white spot lesions: a systematic review and network meta-analysis. (2023) | SMD -0.07 [-0.44, 0.29] | 3 studies | Ungraded |
Multivariable caries prediction model vs Additional prediction model(s) Coronal caries increment · Individuals of all ages · Follow-up ≥1 year, Birpou,2019 [25]; model performance 16 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR+ 1.84 [1.24, 2.74] | 1 study | Ungraded |
Dental caries (caries-active; dmft/DMFT > 0) vs Caries-free individuals (dmft/DMFT = 0) Salivary/biofilm CA VI (carbonic anhydrase VI) concentration · Individuals assessed for dental caries (mainly children aged 2-9 years; one study in adults aged 18-24 years) · Cross-sectional (single time point) Associations of the activity and concentration of carbonic anhydrase VI with susceptibility to dental… (2023) | SMD -0.672 [-1.011, -0.332] | 2 studies · 141 participants | Ungraded |
Multivariable caries prediction model vs Additional prediction model(s) Coronal caries increment · Individuals of all ages · Follow-up ≥1 year, Gao,2013 [29]; model performance 11 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR+ 1.22 [1.15, 1.30] | 1 study | Ungraded |
Multivariable caries prediction model vs Additional prediction model(s) Coronal caries increment · Individuals of all ages · Follow-up ≥1 year, Gao,2013 [29]; model performance 6 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR+ 1.03 [1.01, 1.06] | 1 study | Ungraded |
Fluoride mouthwash (e.g., NaF / amine fluoride) vs Blank control (no mouthwash; before-after comparison) Cariogenic bacteria (Lactobacilli colony count) · Orthodontic patients (any age) undergoing orthodontic treatment (mostly fixed appliances) · >=12 months (long-term) The efficacy of mouthwashes on oral microorganisms and gingivitis in patients undergoing orthodontic… (2023) | Colony count of LB was similar to blank control according to two studies [37, 59]. | 2 studies | Very low |
Elective radical (comprehensive) neck dissection vs Elective selective neck dissection Locoregional recurrence · Adults with oral cavity cancer Interventions for the treatment of oral cavity and oropharyngeal cancers: surgical treatment (2023) · Cochrane | Locoregional recurrence: not reported. | 0 studies | No studies |
Multivariable caries prediction model vs Additional prediction model(s) Coronal caries increment · Individuals of all ages · Follow-up ≥1 year, Beck,1992 [24]; model performance 1 Multivariable prediction models of caries increment: a systematic review and critical appraisal. (2023) | LR+ 2.05 [1.82, 2.31] | 1 study | Ungraded |
Vitamin D deficiency (serum 25(OH)D < 50 nmol/L) vs Normal vitamin D level (serum 25(OH)D ≥ 50 nmol/L) Dental caries · Children (<19 years) · Cohort studies Correlation between vitamin D levels in serum and the risk of dental caries in children: a systematic review… (2023) | RR 1.62 [1.51, 1.74] | 5 studies | Ungraded |
Gum chewing (sugar-free) vs Within-subject before/after comparison of soft gum vs hard gum (no no-gum control) Oral mucosal moisture · Elderly (>60 years) and medically compromised adults with xerostomia / dry mouth · 2-week chewing period (soft then hard gum, with 2-week wash-out) The effect of gum chewing on xerostomia and salivary flow rate in elderly and medically compromised… (2023) | Single study [22] (Nakagawa 2017): chewing hard gum significantly increased oral mucosal moisture whereas chewing soft gum did not. | 1 study · 12 participants | Ungraded |