# Clinical evaluation of a Clematis chinensis Osbeck–containing mouthwash for the prevention of dental caries: a randomized, controlled clinical trial

## TL;DR

A mouthwash containing Clematis chinensis Osbeck extract was tested and found to be effective in preventing dental caries and improving oral health.

## Contribution

This study provides clinical evidence that a natural mouthwash from C. chinensis Osbeck is a safe and effective alternative to chlorhexidine for caries prevention.

## Key findings

- The C. chinensis Osbeck extract reduced plaque acidogenicity and cariogenic bacterial counts.
- User satisfaction increased progressively with the extract mouthwash.
- The extract significantly decreased Streptococcus mutans and Gram-positive cariogenic bacteria.

## Abstract

Chlorhexidine is widely used as a chemical antibacterial mouthwash, but its potential side effects have spurred interest in safer natural alternatives.

This study aimed to evaluate the anticariogenic efficacy and inhibitory effects of a functional mouthwash containing Clematis chinensis Osbeck (C. chinensis Osbeck) extract in a randomized controlled clinical trial.

In this randomized, double-blind, controlled clinical trial conducted at Busan M Dental Clinic, 69 participants were randomly assigned to three groups: saline gargle (n = 23), chlorhexidine gargle (n = 23), and C. chinensis Osbeck extract gargle (n = 23). Participants used 15 mL of the assigned mouthwash four times daily for 2 weeks. The oral environment was standardized with professional scaling and a 1-week recovery period before the intervention. Clinical outcomes were evaluated using the O’Leary index and the Cariview™ test kit (AIOBIO Co. Ltd., Seoul, South Korea) at baseline, 1 week, and 2 weeks, respectively, to evaluate dental plaque acidogenicity and user satisfaction. Saliva tests (including cariogenic bacterial counts, acidogenicity, and buffering capacity) were performed using the SillHa Oral Wellness System (ARKRAY Inc., Kyoto, Japan). Subgingival plaque samples were analyzed by quantitative real-time polymerase chain reaction (PCR) analysis to detect cariogenic bacteria (Streptococcus mutans [S. mutans] and Gram-positive cariogenic bacteria [GS group], comprising S. mitis, S. sobrinus, and Lactobacillus casei). Statistical analyses were performed using analysis of variance (ANOVA) and Duncan’s post hoc test, with significance set at P < 0.05.

The C. chinensis Osbeck extract gargle group showed reductions in the O’Leary index score and cariogenic activity, alongside a progressive increase in user satisfaction. Saliva analysis revealed significant decreases in caries-causing bacterial numbers and acid production and improved buffering capacity, enhancing salivary defense. Only the C. chinensis Osbeck extract gargle group showed a significant reduction in S. mutans and the GS group. Compared with the saline and chlorhexidine groups, this group demonstrated a continuous decrease in caries risk over the 2 weeks.

C. chinensis Osbeck extract significantly improved clinical parameters related to dental caries, suggesting its potential as a safe and effective natural alternative to chemical antibacterial agents for caries prevention and oral health maintenance.

ClinicalTrials.gov, KCT0008539. Registered on June 21, 2023, https://cris.nih.go.kr/cris/search/detailSearch.do/23816).

The online version contains supplementary material available at 10.1186/s13020-025-01258-z.