What do systematic reviews say?

Country-level edentulism prevalence (Global Burden of Disease) vs Low vs high edentulism prevalence

OHRQoL did not differ significantly by country-level edentulism prevalence; no pooled estimate was reported in the text (ungraded).

• Association between oral health-related quality of life and structural determinants of health among elderly… 2025 All outcomes

  Community-dwelling older adults across 25 countries · Across edentulism prevalence categories
  No statistically significant difference in OHRQoL based on edentulism prevalence (Fig. 4c).
  Studies not reported
  GRADE not reported

Country-level dental caries prevalence (Global Burden of Disease) vs Low vs high dental caries prevalence

Lower country-level dental caries prevalence was associated with better OHRQoL (low-prevalence pooled mean 81.5, 95% CI 76.5 to 86.6, higher than high-prevalence countries); statistically significant (ungraded).

• Association between oral health-related quality of life and structural determinants of health among elderly… 2025 All outcomes

  Community-dwelling older adults across 25 countries · Low dental caries prevalence
  MEAN 81.5 [76.5, 86.6]
  Studies not reported
  GRADE not reported

Country-level periodontal disease prevalence (Global Burden of Disease) vs Low vs high periodontal disease prevalence

OHRQoL did not differ significantly by country-level periodontal disease prevalence; no pooled estimate was reported in the text (ungraded).

• Association between oral health-related quality of life and structural determinants of health among elderly… 2025 All outcomes

  Community-dwelling older adults across 25 countries · Across periodontal disease prevalence categories
  No statistically significant difference in OHRQoL based on periodontal disease prevalence (Fig. 4b).
  Studies not reported
  GRADE not reported

Altered-cast impression technique (ACIP), polyether vs One-piece cast technique (OPC), polyether

The review found no eligible studies for this question.

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes
  Not measured
  0 studies
  No studies found

Zinc vs placebo

• Interventions for managing taste disturbances 2017 · Cochrane All outcomes
  Results (health-related quality of life): None of the studies reported data on health-related quality of life. Heckmann 2005 (zinc) reported that signs of depression were less severe (Beck Depression Inventory P<0.05;…
  1 study
  GRADE not reported

Single-stage alginate impression (simplified method) vs Two stage-two step zinc-oxide eugenol (ZoE) traditional method

It is very uncertain whether single-stage alginate impression (simplified method) changes participant-reported oral health-related quality of life (OHIP-EDENT) compared with two stage-two step zinc-oxide eugenol (ZoE) traditional method (very low certainty).

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes

  6 months
  MD 0.5 [-2.67, 3.67]
  1 study · 39 participants
  Very low

Single-stage alginate impression (simplified method) vs Two stage-two step elastomer (silicone, polysulfide, or polyether) conventional method

It is very uncertain whether single-stage alginate impression (simplified method) changes participant-reported oral health-related quality of life (OHIP-EDENT) compared with two stage-two step elastomer (silicone, polysulfide, or polyether)… (very low certainty).

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes

  1 month
  MD 0.05 [-2.37, 2.47]
  2 studies · 98 participants
  Very low

Wax (fluid wax), two stage-two step selective pressure final impression vs Polysulfide rubber (elastomer)

The review found no eligible studies for this question.

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes
  Not measured
  0 studies
  No studies found

Biofunctional Prosthetic System (BPS): closed-mouth two stage-two step final impression with addition silicone elastomer vs Conventional complete denture technique (CCD): open-mouth two stage-two step conventional technique using elastomer

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes

  3 months
  OHIP-EDENT median scores: BPS 34.5; CCD 35.8. No clear difference between groups
  1 study · 10 participants
  Very low

Alginate (two stage-two step final/wash impression) vs Silicone elastomer (two stage-two step)

Alginate (two stage-two step final/wash impression) may leads to higher participant-reported oral health-related quality of life… compared with silicone elastomer (two stage-two step) (low certainty).

• Final‐impression techniques and materials for making complete and removable partial dentures 2018 · Cochrane All outcomes

  2 weeks
  MD 7.20 [2.71, 11.69]
  1 study · 144 participants
  Low

Periodontal disease (present) vs Individuals without periodontal disease (by LOA)

Periodontal disease was associated with higher odds of poor OHRQoL (OR 1.15, 95% CI 1.12-1.18; 3 studies; no heterogeneity; ungraded).

• The Association of Oral Health Status, demographic characteristics and socioeconomic determinants with Oral… 2020 All outcomes

  Upper-middle-income countries (Brazil); studies 2010-2014
  OR 1.15 [1.12, 1.18]
  3 studies
  GRADE not reported

Theory-based oral health education/promotion interventions (HBM, TPB, SCT, HAPA, TTM, PMT, SOC, PRECEDE-PROCEED, MI) vs Control (waitlist, routine/standard oral health education, or minimal intervention)

Theory-based interventions significantly improved oral health-related quality of life (SMD 7.38; low certainty), with very high heterogeneity.

• Health promotion theory-based educational interventions for improving oral health in children and adolescents: a… 2025 All outcomes

  Post-intervention (follow-up 0.5 to 12 months, varies by study) · School-based and community settings; multiple countries (predominantly Iran; also Pakistan, Hong Kong, Lithuania, Thailand) · Overall
  SMD 7.38 [5.57, 9.19]
  4 studies · 4751 participants
  Low

Sodium hypochlorite 5.25% with EDTA 17% vs Sodium hypochlorite 1.3% with MTAD

The review found no eligible studies for this question.

• Irrigants for non‐surgical root canal treatment in mature permanent teeth 2012 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Sodium hypochlorite 5.25% with hydrogen peroxide 3% vs Normal saline

The review found no eligible studies for this question.

• Irrigants for non‐surgical root canal treatment in mature permanent teeth 2012 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Sodium hypochlorite (NaOCl), 2.5% to 5.25% vs Chlorhexidine, 0.2% to 2% (solution or gel)

The review found no eligible studies for this question.

• Irrigants for non‐surgical root canal treatment in mature permanent teeth 2012 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Sodium hypochlorite 1.3% with MTAD final rinse vs Sodium hypochlorite 1.3% with normal saline final rinse

The review found no eligible studies for this question.

• Irrigants for non‐surgical root canal treatment in mature permanent teeth 2012 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Sodium hypochlorite 5.25% vs Sodium hypochlorite 5.25% with hydrogen peroxide 3%

The review found no eligible studies for this question.

• Irrigants for non‐surgical root canal treatment in mature permanent teeth 2012 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Sodium hypochlorite 5.25% vs Normal saline

The review found no eligible studies for this question.

• Irrigants for non‐surgical root canal treatment in mature permanent teeth 2012 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Sodium hypochlorite (NaOCl), 2.5% to 5.25% vs Sodium hypochlorite 1%

The review found no eligible studies for this question.

• Irrigants for non‐surgical root canal treatment in mature permanent teeth 2012 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

Chlorhexidine 0.2% vs Normal saline

The review found no eligible studies for this question.

• Irrigants for non‐surgical root canal treatment in mature permanent teeth 2012 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found