What do systematic reviews say?

Chlorhexidine mouthrinse (any concentration; 0.05% to 0.2%) used in conjunction with mechanical oral hygiene procedures vs Placebo/control mouthrinse, or no mouthrinse (mechanical oral hygiene alone); controls pooled (protocol's separate comparisons versus mechanical oral hygiene alone and versus placebo/control merged)

• Chlorhexidine mouthrinse as an adjunctive treatment for gingival health 2017 · Cochrane All outcomes
  SoF narrative row (Other adverse effects): 22 trials reported at least 1 adverse effect apart from extrinsic tooth staining and calculus formation in the chlorhexidine rinse arms. The adverse effects most commonly…
  22 studies
  GRADE not reported

Chlorhexidine mouthrinse (any concentration; 0.05% to 0.2%) used in conjunction with mechanical oral hygiene procedures vs Placebo/control mouthrinse, or no mouthrinse (mechanical oral hygiene alone); controls pooled (protocol's separate comparisons versus mechanical oral hygiene alone and versus placebo/control merged)

Chlorhexidine mouthrinse (any concentration; 0.05% to 0.2%) used in… showed no clear difference in supragingival calculus formation (various calculus indices) compared with placebo/control mouthrinse, or no mouthrinse (mechanical oral…; GRADE not reported.

• Chlorhexidine mouthrinse as an adjunctive treatment for gingival health 2017 · Cochrane All outcomes

  4 to 6 weeks
  SMD 0.02 [-0.09, 0.14]
  2 studies · 102 participants
  GRADE not reported
• Chlorhexidine mouthrinse as an adjunctive treatment for gingival health 2017 · Cochrane All outcomes

  7 to 12 weeks
  SMD 0.32 [-0.04, 0.69]
  6 studies · 425 participants
  GRADE not reported
• Chlorhexidine mouthrinse as an adjunctive treatment for gingival health 2017 · Cochrane All outcomes

  6 months
  SMD 0.80 [0.33, 1.26]
  4 studies · 323 participants
  GRADE not reported

Chlorhexidine mouthrinse (any concentration; 0.05% to 0.2%) used in conjunction with mechanical oral hygiene procedures vs Placebo/control mouthrinse, or no mouthrinse (mechanical oral hygiene alone); controls pooled (protocol's separate comparisons versus mechanical oral hygiene alone and versus placebo/control merged)

Chlorhexidine mouthrinse (any concentration; 0.05% to 0.2%) used in… leads to lower gingivitis (gingival inflammation) measured by Gingival Index of Loe… compared with placebo/control mouthrinse, or no mouthrinse (mechanical oral… (high certainty).

• Chlorhexidine mouthrinse as an adjunctive treatment for gingival health 2017 · Cochrane All outcomes

  4 to 6 weeks
  MD -0.21 [-0.31, -0.11]
  10 studies · 805 participants
  High
• Chlorhexidine mouthrinse as an adjunctive treatment for gingival health 2017 · Cochrane All outcomes

  6 months
  MD -0.20 [-0.30, -0.11]
  13 studies · 2616 participants
  High

Chlorhexidine mouthrinse (any concentration; 0.05% to 0.2%) used in conjunction with mechanical oral hygiene procedures vs Placebo/control mouthrinse, or no mouthrinse (mechanical oral hygiene alone); controls pooled (protocol's separate comparisons versus mechanical oral hygiene alone and versus placebo/control merged)

Chlorhexidine mouthrinse (any concentration; 0.05% to 0.2%) used in… led to lower gingival bleeding (various bleeding indices) compared with placebo/control mouthrinse, or no mouthrinse (mechanical oral…; GRADE not reported.

• Chlorhexidine mouthrinse as an adjunctive treatment for gingival health 2017 · Cochrane All outcomes

  4 to 6 weeks
  SMD -0.56 [-0.79, -0.33]
  8 studies · 649 participants
  GRADE not reported
• Chlorhexidine mouthrinse as an adjunctive treatment for gingival health 2017 · Cochrane All outcomes

  6 months
  SMD -0.72 [-1.02, -0.42]
  8 studies · 1132 participants
  GRADE not reported

Chlorhexidine mouthrinse (any concentration; 0.05% to 0.2%) used in conjunction with mechanical oral hygiene procedures vs Placebo/control mouthrinse, or no mouthrinse (mechanical oral hygiene alone); controls pooled (protocol's separate comparisons versus mechanical oral hygiene alone and versus placebo/control merged)

Chlorhexidine mouthrinse (any concentration; 0.05% to 0.2%) used in… leads to lower dental plaque (various plaque indices) compared with placebo/control mouthrinse, or no mouthrinse (mechanical oral… (high certainty).

• Chlorhexidine mouthrinse as an adjunctive treatment for gingival health 2017 · Cochrane All outcomes

  6 months
  SMD -1.43 [-1.76, -1.10]
  11 studies · 2075 participants
  High
• Chlorhexidine mouthrinse as an adjunctive treatment for gingival health 2017 · Cochrane All outcomes

  4 to 6 weeks
  SMD -1.45 [-1.90, -1.00]
  12 studies · 950 participants
  High

Chlorhexidine mouthrinse (any concentration; 0.05% to 0.2%) used in conjunction with mechanical oral hygiene procedures vs Placebo/control mouthrinse, or no mouthrinse (mechanical oral hygiene alone); controls pooled (protocol's separate comparisons versus mechanical oral hygiene alone and versus placebo/control merged)

Chlorhexidine mouthrinse (any concentration; 0.05% to 0.2%) used in… led to higher extrinsic tooth staining (various staining indices) compared with placebo/control mouthrinse, or no mouthrinse (mechanical oral…; GRADE not reported.

• Chlorhexidine mouthrinse as an adjunctive treatment for gingival health 2017 · Cochrane All outcomes

  6 months
  SMD 1.54 [1.22, 1.86]
  4 studies · 323 participants
  GRADE not reported
• Chlorhexidine mouthrinse as an adjunctive treatment for gingival health 2017 · Cochrane All outcomes

  4 to 6 weeks
  SMD 1.07 [0.80, 1.34]
  8 studies · 415 participants
  Moderate

Chlorhexidine mouthwash vs placebo

Chlorhexidine 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 placebos according to three studies [34; 48; 52]; colony count of MS was slightly reduced compared to placebo in a short time in one study [40].
  4 studies
  Very low

Chlorhexidine mouthwash vs Blank control

Chlorhexidine mouthwash reduced Mutans streptococci versus blank control, 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 blank control according to one study [53]; one study reported a significant reduction compared to baseline [51].
  2 studies
  Very low

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

Chlorhexidine mouthwash vs Placebo mouthwash

Chlorhexidine mouthwash may reduce pocket probing depth versus placebo in the short term (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)
  PD was significantly reduced except mid-lingual site compared to placebo [32]. The changes of PD were significantly higher compared to placebo [56].
  2 studies
  Low

Chlorhexidine mouthwash vs Blank control

Chlorhexidine mouthwash may reduce the Plaque Index versus blank control in the short term (WMD -0.70, 95% CI -1.12 to -0.27), 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)
  WMD -0.70 [-1.12, -0.27]
  4 studies · 188 participants
  Very low

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

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

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