Efficacy of Clematis chinensis Osbeck extract mouthwash as a complementary therapy for halitosis: A randomized, double-blind controlled trial.

2026-06
Complementary therapies in medicine 98
- Yu-Rin Kim
- Seoul-Hee Nam

PubMed: 41771359
DOI: 10.1016/j.ctim.2026.103340

Study Design

Type: Randomized Controlled Trial (RCT)
Sample size: n = 67
Population: 67 participants
Methods: Randomized, double-blind, controlled clinical trial; 15 mL of assigned solution four times daily for 2 weeks
Blinding: Double-blind
Duration: 2 weeks
Funding: Unclear

Background

Chlorhexidine is a standard agent for halitosis control but has notable adverse effects; therefore, this study aimed to evaluate the effectiveness of a Clematis chinensis Osbeck (C. chinensis Osbeck) extract mouthwash on halitosis and related oral bacteria in comparison with chlorhexidine and saline.

Methods

This randomized, double-blind, controlled clinical trial included 67 participants who were assigned to saline, chlorhexidine, or C. chinensis Osbeck extract mouthwash groups. After professional scaling and a 1-week stabilization period, participants rinsed with 15 mL of the assigned solution four times daily for 2 weeks. Halitosis parameters (oral and exhaled gas levels), salivary ammonia, and nine halitosis-associated bacterial species were measured at baseline, week 1, and week 2. Statistical analyses were performed using analysis of variance (ANOVA) with Tukey's HSD post hoc test, with significance set at p < 0.05.

Results

Both chlorhexidine and C. chinensis Osbeck groups showed significant reductions in perceived halitosis and salivary ammonia (p < 0.05). Only C. chinensis Osbeck group produced significant improvements in Halimeter oral and exhaled gas measures at week 2 (p < 0.05). Bacterial analyses revealed no changes with saline; chlorhexidine group significantly decreased Prevotella intermedia (P. intermedia) and Tannerella forsythia (T. forsythia). The C. chinensis Osbeck group exhibited significant reductions in eight species-Porphyromonas gingivalis, T. forsythia, Treponema denticola, P. intermedia, Prevotella nigrescens, Campylobacter rectus, Staphylococcus aureus, and Actinomyces viscosus-evident by week 1 and more pronounced by week 2 CONCLUSIONS: These findings suggest that a C. chinensis Osbeck extract-based mouthwash effectively reduces halitosis and suppresses a broad spectrum of halitosis-associated oral pathogens.

Research Insights

Clematis→Reduced Halitosis
Both chlorhexidine and C. chinensis Osbeck groups showed significant reductions in perceived halitosis and salivary ammonia (p < 0.05).
Effect
Beneficial
Effect size
Moderate