What do systematic reviews say?

Chewing gum vs No chewing gum

Chewing gum showed no clear difference in oral mucositis (severe) compared with no chewing gum; GRADE not reported.

• Interventions for preventing oral mucositis for patients with cancer receiving treatment 2011 · Cochrane All outcomes

  Median 28 days
  RR 1.16 [0.82, 1.64]
  1 study · 140 participants
  GRADE not reported

Chewing gum vs No chewing gum

Chewing gum showed no clear difference in oral mucositis (any severity) compared with no chewing gum; GRADE not reported.

• Interventions for preventing oral mucositis for patients with cancer receiving treatment 2011 · Cochrane All outcomes

  Median 28 days
  RR 0.87 [0.71, 1.07]
  1 study · 140 participants
  GRADE not reported

V6 chewing gum / mucin chewing gum vs PTC chewing gum (xylitol/sorbitol/mannitol)

• Interventions for the management of dry mouth: topical therapies 2011 · Cochrane All outcomes
  Olsson 1991 (crossover, high risk of bias, n=14): both gums increased saliva secretion, peaking 17.5 minutes after chewing started; significant treatment-by-period interaction; no per-group data presented.
  1 study · 14 participants
  GRADE not reported

Daily chewing gum for 2 weeks or longer vs No gum chewing or control

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• The effect of gum chewing on xerostomia and salivary flow rate in elderly and medically compromised subjects: a… 2023 All outcomes

  2 to 12 weeks · Meta-regression slope for change in standardized salivary flow rate per additional week of chewing · Meta-regression by chewing duration
  SMD per week 0.06
  6 studies · 291 participants
  GRADE not reported

Pycnogenol chewing gum vs Placebo chewing gum

Pycnogenol chewing gum led to lower VSC: hydrogen sulphide compared with placebo chewing gum; GRADE not reported.

• Interventions for managing halitosis 2019 · Cochrane All outcomes

  4 weeks
  MD -114.9 [-206.59, -23.21]
  1 study · 21 participants
  GRADE not reported

Pycnogenol chewing gum vs Placebo chewing gum

Pycnogenol chewing gum showed no clear difference in VSC: methyl mercaptan compared with placebo chewing gum; GRADE not reported.

• Interventions for managing halitosis 2019 · Cochrane All outcomes

  4 weeks
  MD -8.4 [-24.95, 8.15]
  1 study · 21 participants
  GRADE not reported

Pycnogenol chewing gum vs Placebo chewing gum

Pycnogenol chewing gum showed no clear difference in VSC: methyl sulphide compared with placebo chewing gum; GRADE not reported.

• Interventions for managing halitosis 2019 · Cochrane All outcomes

  4 weeks
  MD -4.7 [-27.01, 17.61]
  1 study · 21 participants
  GRADE not reported

0.6% eucalyptus chewing gum vs 0.4% eucalyptus chewing gum

It is very uncertain whether 0.6% eucalyptus chewing gum changes dentist-reported organoleptic test (OLT) score (scale 0 to 5) compared with 0.4% eucalyptus chewing gum (very low certainty).

• Interventions for managing halitosis 2019 · Cochrane All outcomes

  mean 4 weeks
  MD -0.1 [-0.37, 0.17]
  1 study · 64 participants
  Very low

0.6% eucalyptus chewing gum vs Placebo chewing gum

0.6% eucalyptus chewing gum showed no clear difference in volatile sulphur compounds (VSC) compared with placebo chewing gum; GRADE not reported.

• Interventions for managing halitosis 2019 · Cochrane All outcomes

  4 weeks
  MD 0.0 [-0.21, 0.21]
  1 study · 65 participants
  GRADE not reported

0.6% eucalyptus chewing gum vs Placebo chewing gum

The review found no eligible studies for this question.

• Interventions for managing halitosis 2019 · Cochrane All outcomes

  mean 4 weeks
  Patient-reported OLT score: listed in the Summary of findings table but no data reported. No data were reported for patient-reported OLT score.
  0 studies
  No studies found

0.6% eucalyptus chewing gum vs Placebo chewing gum

It is very uncertain whether 0.6% eucalyptus chewing gum changes dentist-reported organoleptic test (OLT) score (scale 0 to 5) compared with placebo chewing gum (very low certainty).

• Interventions for managing halitosis 2019 · Cochrane All outcomes

  mean 4 weeks
  MD -0.1 [-0.31, 0.11]
  1 study · 65 participants
  Very low

0.6% eucalyptus chewing gum vs 0.4% eucalyptus chewing gum

0.6% eucalyptus chewing gum showed no clear difference in volatile sulphur compounds (VSC) compared with 0.4% eucalyptus chewing gum; GRADE not reported.

• Interventions for managing halitosis 2019 · Cochrane All outcomes

  4 weeks
  MD 0.0 [-0.21, 0.21]
  1 study · 64 participants
  GRADE not reported

0.6% eucalyptus chewing gum vs Placebo chewing gum

The review found no eligible studies for this question.

• Interventions for managing halitosis 2019 · Cochrane All outcomes

  mean 4 weeks
  Adverse events: listed in the Summary of findings table but no data reported. No data were reported for adverse events.
  0 studies
  No studies found

Gum chewing (sugar-free) vs No chewing gum

Gum chewing reduced self-reported thirst in most studies (6 of 7 positive, 1 no effect); not meta-analyzed.

• The effect of gum chewing on xerostomia and salivary flow rate in elderly and medically compromised subjects: a… 2023 All outcomes

  Various (preoperative period to 3 + 1 months) · Haemodialysis units, elderly / geriatric care, cancer and palliative care, and xerostomia / hyposalivation clinics (studies from multiple countries)
  Narrative vote-count: of 7 studies measuring thirst, 6 found gum chewing reduced thirst [16,20,21,26,27,31] and 1 detected no effect [29].
  7 studies
  GRADE not reported

Gum chewing (sugar-free) vs No chewing gum

Across 19 studies the effect of gum chewing on stimulated and/or unstimulated salivary flow rate was mixed (9 positive, 10 no effect); this broad outcome was not meta-analyzed.

• The effect of gum chewing on xerostomia and salivary flow rate in elderly and medically compromised subjects: a… 2023 All outcomes

  Various (single session to 12 months) · Haemodialysis units, elderly / geriatric care, cancer and palliative care, and xerostomia / hyposalivation clinics (studies from multiple countries)
  Narrative vote-count: of 19 studies measuring stimulated and/or unstimulated saliva flow rate, 9 found a positive effect of gum chewing [17,18,22,24,27,35,36,38,39] and 10 detected no effect…
  19 studies
  GRADE not reported

Gum chewing (sugar-free) vs No chewing gum

In elderly and medically compromised people with xerostomia, chewing sugar-free gum daily for two or more weeks produces a small but statistically significant increase in unstimulated whole salivary flow rate versus no gum (SMD 0.44, 95% CI 0.22 to 0.66); certainty of evidence was not formally graded.

• The effect of gum chewing on xerostomia and salivary flow rate in elderly and medically compromised subjects: a… 2023 All outcomes

  Gum chewed daily for >=2 weeks (2 to 12 weeks; multiple time points for Kim and Ozen) · Haemodialysis units, elderly / geriatric care, cancer and palliative care, and xerostomia / hyposalivation clinics (studies from multiple countries)
  SMD 0.44 [0.22, 0.66]
  6 studies · 291 participants
  GRADE not reported

Gum chewing (sugar-free) vs No chewing gum

Gum chewing was linked with improved self-reported xerostomia / dry mouth in most studies (12 of 17 positive, 5 no effect); heterogeneous instruments precluded meta-analysis.

• The effect of gum chewing on xerostomia and salivary flow rate in elderly and medically compromised subjects: a… 2023 All outcomes

  Various (single session to 3 months) · Haemodialysis units, elderly / geriatric care, cancer and palliative care, and xerostomia / hyposalivation clinics (studies from multiple countries)
  Narrative vote-count: of 17 studies measuring self-reported xerostomia / dry mouth, 12 found a positive effect of gum chewing [18,19,21,23,24,25,26,27,30,31,38,40] and 5 detected no effect [17,29,33,34,37]. No study…
  17 studies
  GRADE not reported

V6 chewing gum / mucin chewing gum vs Placebo chewing gum

• Interventions for the management of dry mouth: topical therapies 2011 · Cochrane All outcomes
  Aagaard 1992 (crossover, n=43): approximately 50% of participants had an increase in unstimulated whole saliva from all products; unclear how many completed the trial; no usable data.
  1 study · 43 participants
  GRADE not reported

V6 chewing gum / mucin chewing gum vs Placebo chewing gum

• Interventions for the management of dry mouth: topical therapies 2011 · Cochrane All outcomes
  Preference favoured mucin gum (61%) over V6 (21%) and placebo (5%).
  1 study · 43 participants
  GRADE not reported

Gum chewing (sugar-free) vs Within-subject before/after comparison of soft gum vs hard gum (no no-gum control)

One small study found that chewing hard (but not soft) gum increased oral mucosal moisture.

• The effect of gum chewing on xerostomia and salivary flow rate in elderly and medically compromised subjects: a… 2023 All outcomes

  2-week chewing period (soft then hard gum, with 2-week wash-out) · Haemodialysis units, elderly / geriatric care, cancer and palliative care, and xerostomia / hyposalivation clinics (studies from multiple countries)
  Single study [22] (Nakagawa 2017): chewing hard gum significantly increased oral mucosal moisture whereas chewing soft gum did not.
  1 study · 12 participants
  GRADE not reported