What do systematic reviews say?

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)

The review found no eligible studies for this question.

• Dental extractions prior to radiotherapy to the jaws for reducing post‐radiotherapy dental complications 2013 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

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)

The review found no eligible studies for this question.

• Dental extractions prior to radiotherapy to the jaws for reducing post‐radiotherapy dental complications 2013 · Cochrane All outcomes
  no estimate extracted
  0 studies
  No studies found

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

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

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

Antidepressants (trazodone 200 mg/day) vs placebo

• Interventions for treating burning mouth syndrome 2016 · Cochrane All outcomes

  short-term (up to 3 months)
  SoF1. Change in QoL short-term (mean Beck Depression Inventory, 0-63, lower better): this single study narratively reported that both intervention and placebo participants were less depressed at trial completion, but…
  1 study · 37 participants
  Very low

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

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

Ibuprofen taken pre-emptively (about 1 hour before treatment) vs Ibuprofen taken post-treatment

The review found no eligible studies for this question.

• Pharmacological interventions for pain relief during orthodontic treatment 2017 · Cochrane All outcomes
  No studies in this comparison reported this outcome.
  0 studies
  No studies found

Prophylactic aciclovir (oral or intravenous) vs placebo

The review found no eligible studies for this question.

• Interventions for the prevention and treatment of herpes simplex virus in patients being treated for cancer 2009 · Cochrane All outcomes
  None of the prophylactic aciclovir versus placebo trials reported on patient quality of life. For prevention or treatment, no trials reported on duration of hospital stay, amount of analgesia or patient quality of life.
  0 studies
  No studies found

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

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 no intervention or another intervention

The review found no eligible studies for this question.

• Interventions for managing relapse of the lower front teeth after orthodontic treatment 2013 · Cochrane All outcomes
  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 found

Bee propolis (one 500 mg capsule per day) vs placebo

• Systemic interventions for recurrent aphthous stomatitis (mouth ulcers) 2012 · Cochrane All outcomes

  6 months (minimum)
  Patients in the propolis group self-reported a significant improvement in their quality of life (P=0.03), based on volunteered statements of self-reported improvement.
  1 study · 19 participants
  GRADE not reported

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