Effect of different mouthrinses on morning breath

J Periodontol. 2001 Sep;72(9):1183-91. doi: 10.1902/jop.2000.72.9.1183.


Background: Morning breath odor is an often-encountered complaint. This double-blind, crossover, randomized study aimed to examine the bad breath-inhibiting effect of 3 commercially available mouthrinses on morning halitosis during an experimental period of 12 days without mechanical plaque control.

Methods: Twelve medical students with a healthy periodontium refrained from all means of mechanical plaque control during 3 experimental periods of 12 days (with intervening washout periods of at least 3 weeks). A professional oral cleaning preceded each period. During each experimental period, as the only oral hygiene measure allowed, the students rinsed twice a day with one of the following formulations in a randomized order: CHX-Alc (a 0.2% chlorhexidine [CHX] solution); CHX-NaF (CHX 0.12% plus sodium fluoride 0.05%); or CHX-CPC-Zn (CHX 0.05% plus cetylpyridinium chloride 0.05% plus zinc lactate 0.14%). After 12 days, morning breath was scored via volatile sulfur compound (VSC) level measurements of the mouth air and organoleptic ratings of the mouth air, the expired air, and a scraping of the tongue coating. At the 12-day visit, a questionnaire (subjective ratings) was completed and samples taken from both the tongue coating and the saliva for anaerobic and aerobic culturing and vitality staining. The de novo supragingival plaque formation was also recorded. All parameters were correlated with the baseline registrations.

Results: Although oral hygiene during the 3 experimental periods was limited to oral rinses, bad breath parameters systematically improved, with the exception of a slight increase in VSC levels while using CHX-Alc, a finding which was associated with the direct influence of the CHX on the sulfide monitor. The oral microbial load after the use of CHX-NaF remained unchanged, while for the CHX-Alc and CHX-CPC-Zn, significant reductions in both aerobic and anaerobic colony forming units (CFU)/ml were noticed in comparison with baseline data for both tongue coating and saliva samples. The composition of microflora, on the other hand, did not reveal significant changes. The supragingival plaque formation was inhibited, in descending order, by CHX-Alc, CHX-CPC-Zn, and CHX-NaF. The subjective scores for the rinses indicated a higher appreciation for CHX-CPC-Alc and CHX-NaF because of a better taste and fewer side effects.

Conclusions: The results of this study demonstrate that morning halitosis can be successfully reduced via daily use of mouthrinses. CHX-Alc and CHX-CPC-Zn mouthrinses result in a significant reduction of the microbial load of tongue and saliva.

Publication types

  • Clinical Trial
  • Randomized Controlled Trial

MeSH terms

  • Adult
  • Anti-Infective Agents, Local / pharmacology
  • Anti-Infective Agents, Local / therapeutic use*
  • Bacteria, Anaerobic / drug effects
  • Breath Tests
  • Cetylpyridinium / pharmacology
  • Cetylpyridinium / therapeutic use*
  • Chlorhexidine / pharmacology
  • Chlorhexidine / therapeutic use*
  • Circadian Rhythm
  • Colony Count, Microbial
  • Cross-Over Studies
  • Dental Plaque / prevention & control
  • Double-Blind Method
  • Drug Combinations
  • Female
  • Gingivitis / prevention & control
  • Halitosis / drug therapy*
  • Halitosis / microbiology
  • Humans
  • Male
  • Mouthwashes / pharmacology
  • Mouthwashes / therapeutic use*
  • Saliva / microbiology
  • Sodium Fluoride / pharmacology
  • Sodium Fluoride / therapeutic use
  • Statistics, Nonparametric
  • Sulfhydryl Compounds / metabolism
  • Sulfides / metabolism
  • Surveys and Questionnaires
  • Tongue / microbiology
  • Zinc Compounds / pharmacology
  • Zinc Compounds / therapeutic use


  • Anti-Infective Agents, Local
  • Drug Combinations
  • Mouthwashes
  • Sulfhydryl Compounds
  • Sulfides
  • Zinc Compounds
  • methylmercaptan
  • Sodium Fluoride
  • Cetylpyridinium
  • Chlorhexidine