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

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

Completed orthodontic treatment vs No previous or incomplete orthodontic treatment

The umbrella review reported better oral health-related quality of life after completed orthodontic treatment.

• Oral-health-related quality of life in adolescents: umbrella review. 2023 All outcomes
  no estimate extracted
  Studies not reported
  GRADE not reported

Restorative dental treatment under general anesthesia vs Before treatment (before-after)

One study found restorative dental treatment under general anesthesia significantly improved oral health-related quality of life for preschool children and their families (narrative synthesis; not GRADE-rated).

• Oral Health of Children and Adolescents in the United Arab Emirates: A Systematic Review of the Past Decade. 2021 All outcomes

  UAE
  Alantali et al. found that restorative dental general anesthesia resulted in significant improvement in child and family physical, psychological and social quality-of-life, with a large change noted in both the child…
  1 study
  GRADE not reported