What do systematic reviews say?

Herbal mouthwash vs placebo

Herbal mouthwash reduced gingival inflammation-related indices versus placebo, but certainty is very low.

• The efficacy of mouthwashes on oral microorganisms and gingivitis in patients undergoing orthodontic treatment:… 2023 All outcomes

  ≤ 3 months
  GBI was significantly reduced compared to placebo [41]; GBI was significantly reduced compared to placebo [56]; BI was significantly reduced compared to placebo [40].
  3 studies
  Very low

Herbal mouthwash vs Blank control

Herbal mouthwash probably reduces the Gingival Index versus blank control in the short term (WMD -0.20, 95% CI -0.32 to -0.09; moderate certainty).

• The efficacy of mouthwashes on oral microorganisms and gingivitis in patients undergoing orthodontic treatment:… 2023 All outcomes

  <=3 months (short-term) · Orthodontic patients undergoing orthodontic treatment (randomized controlled trials; multiple countries)
  WMD -0.20 [-0.32, -0.09]
  3 studies · 132 participants
  Moderate

Chlorhexidine mouthwash vs placebo

Chlorhexidine mouthwash reduced Plaque Index versus placebo, but certainty is very low.

• The efficacy of mouthwashes on oral microorganisms and gingivitis in patients undergoing orthodontic treatment:… 2023 All outcomes

  ≤ 3 months
  Plaque Index was significantly reduced compared to placebos according to two studies [20; 32].
  2 studies
  Very low

Clear aligners (Invisalign / thermoformed aligners) vs Conventional orthodontic appliance treatment

Both included studies reported higher salivary caries-associated bacteria (S. mutans and Lactobacilli) with fixed appliances than clear aligners; not meta-analyzed (ungraded).

• White spot lesions, plaque accumulation and salivary caries-associated bacteria in clear aligners compared to fixed… 2023 All outcomes

  3 and 6 months · University/hospital orthodontic clinics and private practice (multiple countries)
  Not meta-analyzed (insufficient number of studies). Both included observational studies (Mummolo 2020 [19]; Mummolo 2020 [25]) reported a higher number of subjects with S. mutans and Lactobacilli >10^5 CFU/mL in the…
  2 studies
  GRADE not reported

Probiotic mouthwash (e.g., Lactobacillus-based) vs Blank control

Probiotic mouthwash has inconsistent effects on Mutans streptococci colony counts versus blank control; the evidence is very uncertain (very low certainty).

• The efficacy of mouthwashes on oral microorganisms and gingivitis in patients undergoing orthodontic treatment:… 2023 All outcomes

  <=3 months (short-term) · Orthodontic patients undergoing orthodontic treatment (randomized controlled trials; multiple countries)
  Colony count of MS was significantly reduced compared to blank control [53]. Colony count of MS was insignificantly increased compared to baseline [33].
  2 studies
  Very low

Chlorhexidine mouthwash vs Placebo mouthwash

Chlorhexidine mouthwash probably reduces the Gingival Index versus placebo in the short term (WMD -0.45, 95% CI -0.70 to -0.20; low certainty).

• The efficacy of mouthwashes on oral microorganisms and gingivitis in patients undergoing orthodontic treatment:… 2023 All outcomes

  <=3 months (short-term) · Orthodontic patients undergoing orthodontic treatment (randomized controlled trials; multiple countries)
  WMD -0.45 [-0.70, -0.20]
  3 studies · 98 participants
  Low

Periodontal disease (periodontitis; clinical attachment loss >=4 mm) vs Adults without periodontal disease (healthy periodontal status; CAL <=3 mm)

Adults with periodontal disease had significantly higher odds of root caries than those without (pooled OR 1.38, 95% CI 1.25 to 1.53; 2 observational studies; low certainty).

• Is there an association between periodontal disease and root caries? A systematic review and meta-analysis. 2023 All outcomes

  Population-based dental surveys: England (Adult Dental Health Survey 2009) and China (4th National Oral Health Survey) for the two pooled studies; included studies from China, England, Japan, and Finland
  OR 1.38 [1.25, 1.53]
  2 studies · 7664 participants
  Low

Herbal mouthwash vs Blank control

Herbal mouthwash reduced several plaque-related indices, but certainty is very low.

• The efficacy of mouthwashes on oral microorganisms and gingivitis in patients undergoing orthodontic treatment:… 2023 All outcomes

  ≤ 3 months
  PI was significantly reduced compared to baseline [39; 48; 54; 58]; BBPI was significantly reduced compared to blank control [47]; TI and dental plaque amount were significantly reduced compared to baseline [45; 38].
  8 studies
  Very low

Chlorhexidine mouthwash vs Blank control

Chlorhexidine mouthwash may reduce total bacteria colony counts versus blank control in the short term, but the evidence is very uncertain (very low certainty).

• The efficacy of mouthwashes on oral microorganisms and gingivitis in patients undergoing orthodontic treatment:… 2023 All outcomes

  <=3 months (short-term) · Orthodontic patients undergoing orthodontic treatment (randomized controlled trials; multiple countries)
  Colony count of total bacteria were significantly reduced compared to placebos according to two studies [34, 43].
  2 studies
  Very low

Herbal mouthwash vs Blank control

Herbal mouthwash reduced some gingival inflammation-related indices, but certainty is very low.

• The efficacy of mouthwashes on oral microorganisms and gingivitis in patients undergoing orthodontic treatment:… 2023 All outcomes

  ≤ 3 months
  CPI was significantly reduced compared to baseline [35]; SBI was significantly reduced while MGI was similar compared to baseline [45]; BOP was significantly reduced compared to blank control [39].
  3 studies
  Very low

Herbal mouthwash vs Blank control

Herbal mouthwash showed mixed effects on Mutans streptococci, with very low-certainty evidence.

• The efficacy of mouthwashes on oral microorganisms and gingivitis in patients undergoing orthodontic treatment:… 2023 All outcomes

  ≤ 3 months
  Colony count of MS was significantly reduced compared to baseline [48]; another study found an insignificant reduction compared to baseline [51].
  2 studies
  Very low

Intervention not reported

• A Systematic Review and Meta-Analysis of the Role of Sugar-Free Chewing Gum on Plaque Quantity in the Oral Cavity. 2022 All outcomes
  No adverse events reported
  8 studies
  GRADE not reported

Consumption of xylitol chewing gum by women (mothers) vs No chewing gum

Xylitol sugar-free gum significantly reduced plaque quantity versus no-gum/control (SMD -0.743, 95% CI -1.148 to -0.338), with high heterogeneity (I2 = 86.0%; ungraded).

• A Systematic Review and Meta-Analysis of the Role of Sugar-Free Chewing Gum on Plaque Quantity in the Oral Cavity. 2022 All outcomes

  End of study (last reported time point; study durations 4 days to 2 years) · Community, residential care homes, and schools; predominantly adults
  SMD -0.743 [-1.148, -0.338]
  7 studies
  GRADE not reported

Gum chewing (sugar-free) vs No chewing gum

Sugar-free chewing gum significantly reduced plaque quantity versus no-gum/control (SMD -0.778, 95% CI -1.167 to -0.390), with high heterogeneity (I2 = 86.6%) and no GRADE rating (ungraded).

• A Systematic Review and Meta-Analysis of the Role of Sugar-Free Chewing Gum on Plaque Quantity in the Oral Cavity. 2022 All outcomes

  End of study (last reported time point; study durations 4 days to 2 years) · Community, residential care homes, and schools; predominantly adults
  SMD -0.778 [-1.167, -0.390]
  7 studies
  GRADE not reported
• A Systematic Review and Meta-Analysis of the Role of Sugar-Free Chewing Gum on Plaque Quantity in the Oral Cavity. 2022 All outcomes

  End of study (last reported time point; study durations 4 days to 2 years) · Community, residential care homes, and schools; predominantly adults · Sensitivity analysis (pre-post correlation set to 0.95 for the SFG group)
  SMD -1.098 [-1.539, -0.656]
  7 studies
  GRADE not reported

Illicit drug use vs People who do not use drugs

Illicit drug use was associated with substantially higher odds of dental caries experience (DMFT) (pooled OR 4.11, 95% CI 2.07-8.15; 7 studies; high heterogeneity I2=90.5%; ungraded).

• Dental caries and periodontal disease among people who use drugs: a systematic review and meta-analysis. 2020 All outcomes

  High-income countries (USA, Germany, Australia, Croatia) and India (low/middle-income); studies 2007-2016
  OR 4.11 [2.07, 8.15]
  7 studies
  GRADE not reported

Illicit drug use vs People who do not use drugs

Illicit drug use was not significantly associated with periodontal disease (pooled OR 1.44, 95% CI 0.80-2.60; 5 studies; substantial heterogeneity I2=85%; ungraded).

• Dental caries and periodontal disease among people who use drugs: a systematic review and meta-analysis. 2020 All outcomes

  High-income countries (USA, Germany, New Zealand, Saudi Arabia) and India; studies 2008-2016
  OR 1.44 [0.80, 2.60]
  5 studies
  GRADE not reported

Placebo rinse vs Pre-treatment (baseline, same group)

Placebo rinse did not significantly change Lactobacillus counts relative to baseline; not GRADE-rated.

• The antiplaque/anticariogenic efficacy of Salvadora persica (Miswak) mouthrinse in comparison to that of… 2019 All outcomes

  Pre- vs post-treatment · In vivo clinical trial (human oral cavity)
  MD 0.34 [-0.50, 1.18]
  2 studies · 30 participants
  GRADE not reported

Salvadora persica (miswak) mouthrinse vs Pre-treatment (baseline, same group)

Salvadora persica rinse reduced Lactobacillus counts relative to baseline; not GRADE-rated.

• The antiplaque/anticariogenic efficacy of Salvadora persica (Miswak) mouthrinse in comparison to that of… 2019 All outcomes

  Pre- vs post-treatment · In vivo clinical trial (human oral cavity)
  MD 1.54 [0.91, 2.17]
  2 studies · 30 participants
  GRADE not reported

Salvadora persica (miswak) mouthrinse vs Chlorhexidine mouthrinse

When usual mechanical plaque control continued, Salvadora persica and chlorhexidine did not differ significantly for plaque; not GRADE-rated.

• The antiplaque/anticariogenic efficacy of Salvadora persica (Miswak) mouthrinse in comparison to that of… 2019 All outcomes

  Post-intervention · In vivo clinical trial (human oral cavity) · Did not refrain from mechanical plaque control
  MD 0.17 [-0.08, 0.42]
  11 studies · 594 participants
  GRADE not reported
• The antiplaque/anticariogenic efficacy of Salvadora persica (Miswak) mouthrinse in comparison to that of… 2019 All outcomes

  Post-intervention · In vivo clinical trial (human oral cavity) · Duration of mouthwash use: >=3 weeks
  MD 0.24 [-0.11, 0.60]
  7 studies · 420 participants
  GRADE not reported
• The antiplaque/anticariogenic efficacy of Salvadora persica (Miswak) mouthrinse in comparison to that of… 2019 All outcomes

  Post-intervention · In vivo clinical trial (human oral cavity)
  MD 0.19 [0.01, 0.37]
  18 studies · 902 participants
  GRADE not reported

Salvadora persica (miswak) mouthrinse vs Chlorhexidine 0.2% mouthrinse

Salvadora persica was less effective than 0.2% chlorhexidine at reducing plaque (favours chlorhexidine); not GRADE-rated.

• The antiplaque/anticariogenic efficacy of Salvadora persica (Miswak) mouthrinse in comparison to that of… 2019 All outcomes

  Post-intervention · In vivo clinical trial (human oral cavity) · Chlorhexidine concentration: 0.2%
  MD 0.12 [0.03, 0.21]
  12 studies · 566 participants
  GRADE not reported