The efficacy of two oral hygiene regimens in reducing oral malodour: a randomised clinical trial

Abstract

Objectives: This study compared the efficacy of two oral hygiene regimens in reducing oral malodour and the proportions of bacterial species involved in the production of volatile sulphur compounds.

Material and methods: Seventy subjects who participated in a halitosis-induction phase and achieved an organoleptic score of ≥ 3.0 [time point 0 (T0)] randomised into two groups: brushing with regular fluoride toothpaste alone (control group) or brushing with regular fluoride toothpaste followed by rinsing with a 0.075% cetylpyridinium chloride (CPC) mouthwash (CPC group). Subjects followed their assigned oral hygiene regimen for 21 days. Then, they underwent an organoleptic examination and measurement of volatile sulphur compounds (VSCs) using a portable gas chromatograph, 12 hours after their last oral hygiene procedure (T1) and 4 hours after an on-site oral hygiene (T2). Microbiological samples (supragingival biofilm, tongue coating and saliva) were analysed using checkerboard DNA-DNA hybridisation.

Results: Both therapies statistically significantly improved the organoleptic scores (P < 0.05), but the VSC levels and/or concentrations were reduced only in the CPC group (P < 0.05). In subjects rinsing with CPC, oral malodour scores were reduced by 49% at the 4-hour assessment (T2) compared with those not rinsing (P < 0.05). Red-complex pathogens were reduced more effectively in the CPC group than in the control group.

Conclusions: Brushing followed by rinsing with a 0.075% CPC mouthwash provided statistically significantly greater reductions in oral malodour, measured organoleptically and instrumentally, and in the proportions of red-complex species when compared with brushing alone.

Keywords: Halitosis; antimicrobial activity; cetylpyridinium chloride; mouthwash; oral malodour; treatment.

Figure 1.

Flow chart of the study design.

Figure 2.

Mean percentage of DNA probe counts of the 40 test species in saliva samples at baseline (T0) and 4 hours post-treatment (T2) in each protocol of oral hygiene (control and CPC). The species were ordered according to the microbial complexes described by Socransky et al. The significance of differences within each group between time points was assessed using the Wilcoxon test (*P < 0.05; **P < 0.01). Control, brushing twice daily with toothpaste alone; CPC, brushing twice daily with toothpaste followed by rinsing with a mouthwash containing 0.075% cetylpyridinium chloride.

Figure 3.

Mean percentage of DNA probe counts of the 40 test species in tongue-coating samples at baseline (T0) and 4 hours post-treatment (T2) in each protocol of oral hygiene (control and CPC). The species were ordered according to the microbial complexes described by Socransky et al. The significance of differences within each group between time points was assessed using the Wilcoxon test (*P < 0.05; **P < 0.01; ***P < 0.001). Control group, brushing twice daily with toothpaste alone; CPC group, brushing twice daily with toothpaste followed by rinsing with a mouthwash containing 0.075% cetylpyridinium chloride.

Figure 4.

Mean percentage of DNA probe counts of the 40 test species in supragingival biofilm samples at baseline (T0) and 4 hours post-treatment (T2) in each protocol of oral hygiene (control and CPC). The species were ordered according to the microbial complexes described by Socransky et al. The significance of differences within each group between time points was assessed using the Wilcoxon test (*P < 0.05; **P < 0.01; ***P < 0.001). Control group, brushing twice daily with toothpaste alone; CPC group, brushing twice daily with toothpaste followed by rinsing with a mouthwash containing 0.075% cetylpyridinium chloride.

Figure 5.

Pie charts of the mean proportion of each microbial complex at baseline (T0) and 4 hours post-treatment (T2) in each protocol of oral hygiene (control and CPC). The colours represent different microbial complexes and Actinomyces species (blue) in samples of saliva, tongue coating and supragingival biofilm. The significance of differences within each group between time points was assessed using the Wilcoxon test (*P < 0.05). The significance of differences between groups at each time point was assessed using the Mann–Whitney U-test (different capital letters indicate differences between groups). Control group, brushing twice daily with toothpaste alone; CPC group, brushing twice daily with toothpaste followed by rinsing with a mouthwash containing 0.075% cetylpyridinium chloride.