What do systematic reviews say?

Cetylpyridinium chloride mouthwash vs Blank control

CPC mouthwash may reduce plaque-related indexes 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)
  BBPI was significantly reduced compared to blank control [47]. PI was significantly reduced compared to blank control [50]. The amount of dental plaque was significantly reduced compared to baseline [38].
  3 studies
  Very low

Herbal mouthwash vs placebo

Herbal mouthwash reduced Mutans streptococci 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
  Colony count of MS was significantly reduced compared to placebo [52]; colony count was slightly reduced compared to placebo in a short time in one study [40].
  2 studies
  Very low

Fluoride mouthwash vs Blank control

Short-term fluoride mouthwash has uncertain effects on gingival inflammation-related indexes versus blank control (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)
  MGI' and BI' was significantly reduced compared to baseline [34]. BOP and GI was slightly lower compared to blank control [46].
  2 studies
  Very low

Fluoride mouthwash vs Blank control

Long-term fluoride mouthwash showed mixed plaque-index effects, with very low-certainty evidence.

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

  ≥ 12 months
  PI was similar to blank control [37]; API was slightly reduced compared to blank control and significant at 6 and 9 months [59].
  2 studies
  Very low
• The efficacy of mouthwashes on oral microorganisms and gingivitis in patients undergoing orthodontic treatment:… 2023 All outcomes

  ≤ 3 months
  TI was significantly reduced compared to baseline [34]; PI was significantly reduced compared to baseline but similar to blank control [46].
  2 studies
  Very low

Fluoride mouthwash vs Blank control

Long-term (>=12 months) fluoride mouthwash may make little or no difference to Lactobacilli colony counts versus blank control (very low certainty).

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

  >=12 months (long-term) · Orthodontic patients undergoing orthodontic treatment (randomized controlled trials; multiple countries)
  Colony count of LB was similar to blank control according to two studies [37, 59].
  2 studies
  Very low

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

White spot lesion severity was assessed narratively in a small number of studies and not meta-analyzed; evidence is limited (ungraded).

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

  Baseline to end of treatment (varying) · University/hospital orthodontic clinics and private practice (multiple countries)
  Not meta-analyzed. 2 RCTs assessed WSL severity by lesion surface area (Albhaisi 2020 [12]; Alshatti 2017 [31]) and 1 (Albhaisi 2020 [12]) also by lesion depth; reported narratively with differing methods, generally…
  2 studies
  GRADE not reported

Chlorhexidine mouthwash vs Blank control

Chlorhexidine mouthwash may reduce the Gingival Index versus blank control in the short term (WMD -0.54, 95% CI -0.96 to -0.13), but with very high heterogeneity 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)
  WMD -0.54 [-0.96, -0.13]
  6 studies · 274 participants
  Very low

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

Full-mouth scaling (FMS): scaling/root planing (subgingival instrumentation) of all quadrants within 24 hours, without antiseptic vs Quadrant scaling and root planing (control): SRP of each quadrant in separate sessions at least one week apart

Full-mouth scaling (FMS): scaling/root planing (subgingival… showed no clear difference in change in clinical attachment level (CAL) compared with quadrant scaling and root planing (control): SRP of each quadrant in… (low certainty).

• Full‐mouth treatment modalities (within 24 hours) for periodontitis in adults 2022 · Cochrane All outcomes

  6 to 8 months (SoF); similar at 3 to 4 months
  MD 0.10 [-0.05, 0.26]
  5 studies · 148 participants
  Low