HalitosisCHX+CDONCT07265102
Effect of a Mouthwash Containing Chlorhexidine and Chlorine Dioxide on Halitosis
A study testing CHX 0.01% + CDO 0.05% mouthwash in people with Halitosis, run by Can Tho University of Medicine and Pharmacy at 1 site in Vietnam.
Trial summary
Halitosis significantly impacts the quality of a patient's life. This randomized, double-blind crossover trial evaluates a mouthwash containing chlorhexidine (0.01%) and chlorine dioxide (0.05%) compared with placebo. Forty participants rinsed twice daily for 2 weeks, followed by a 2-week washout and crossover. Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Halitosis
- What is being tested?
- CHX 0.01% + CDO 0.05% mouthwash
- Could I receive a placebo?
- Yes, some participants may receive a placebo
- How many people
- 40 participants
- Where
- 1 siteVietnam
- Study dates
- 5 Sep 2023to 5 Mar 2024
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- ≥20 natural teeth
- H₂S >1.5 ng/10ml or CH₃SH >0.5 ng/10ml
- Signed informed consent
Who cannot join
- Systemic disease
- Smoking
- Pregnancy or lactation
- Periodontal pockets ≥4 mm
- Recent antibiotic use (<1 month)
- Orthodontic appliances or dentures
- Allergy to CHX or C
Trial locations and contacts
1 site in 1 country.
Vietnam1 site
Odonto-Stomatology Hospital of Ho Chi Minh City
Ho Chi Minh City, 70000
About this study
Official title: A Randomized Double-Blind Crossover Clinical Trial Evaluating the Efficacy of a Mouthwash Containing Chlorhexidine and Chlorine Dioxide in Patients With Oral Malodor
Halitosis significantly impacts the quality of a patient's life. This randomized, double-blind crossover trial evaluates a mouthwash containing chlorhexidine (0.01%) and chlorine dioxide (0.05%) compared with placebo. Forty participants rinsed twice daily for 2 weeks, followed by a 2-week washout and crossover. The primary outcomes were volatile sulfur compounds (H₂S, CH₃SH), measured by OralChroma. Secondary outcomes included plaque index, gingival index, bleeding on probing, tongue coating, and salivary bacterial counts (Aa, Pg, Fn, Pi, and Ec).
- Conditions
- Halitosis
- Being tested
- CHX 0.01% + CDO 0.05% mouthwash, Placebo mouthwash
- Keywords
- halitosis, chlorhexidine, chlorine dioxide, mouthwash, volatile sulfur compounds, tongue coating
- Medical subject headings
- Halitosis
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
CHX 0.01% + CDO 0.05% mouthwashOther
Also called CHX+ CDO mouthwash
Mouthwash formulation containing chlorhexidine 0.01% and chlorine dioxide 0.05%, prepared by the Department of Pharmacy, University of Medicine and Pharmacy at Ho Chi Minh City.
Placebo mouthwashOther
Also called Control mouthwash
Identical placebo formulation matched in flavor, color, and excipients but without active ingredients (CHX or CDO).
| Study group | Role | What they receive |
|---|---|---|
| CHX-CDO Mouthwash | Experimental | Participants rinsed with a test mouthwash containing 0.01% chlorhexidine and 0.05% chlorine dioxide. Each participant used 15 mL of the solution twice daily (morning and evening) for 30 seconds over a period of 2 weeks. The mouthwash bottles were identical in appearance to maintain blinding. Receives: Other: CHX 0.01% + CDO 0.05% mouthwash |
| Placebo Mouthwash | Placebo comparator | Participants rinsed with a placebo mouthwash containing the same excipients, color, and flavoring agents but without chlorhexidine or chlorine dioxide. Each participant used 15 mL of the placebo solution twice daily for 30 seconds over 2 weeks. Receives: Other: Placebo mouthwash |
What is being measured
The primary outcome is the main question the study is designed to answer.
Change in Hydrogen sulfide (H₂S) concentration in breath
The concentration of hydrogen sulfide (H₂S) in oral breath was measured using the OralChroma™ device. The difference between baseline, immediately after rinsing, and 2 weeks was used to assess the efficacy of the mouthwash in reducing volatile sulfur compounds.
Measured: baseline, immediate post-rinse, 2 weeks
Change in Methyl mercaptan (CH₃SH) concentration in breath
The concentration of methyl mercaptan (CH₃SH) in oral breath was measured using the OralChroma™ device. The difference between baseline, immediately after rinsing, and 2 weeks was used to evaluate the short-term and sustained effects of the mouthwash on halitosis.
Measured: Baseline, immediate post-rinse, 2 weeks
Secondary outcomes (5)
Change of plaque index
The Plaque Index (PI) was recorded at four surfaces per tooth (mesiobuccal, buccal, distobuccal, and lingual) to assess plaque accumulation. Each surface was scored on a scale from 0 to 3, where 0 indicates no plaque and 3 indicates abundant plaque accumulation. The mean PI score per participant was calculated at each visit. A lower score indicates less plaque accumulation and improved oral hygiene.
Measured: At baseline and 2 weeks of mouthwash use
Change in Gingival Index (GI)
The Gingival Index (GI) was evaluated at four surfaces per tooth (mesiobuccal, buccal, distobuccal, and lingual) to assess the degree of gingival inflammation. Each surface was scored on a scale from 0 to 3, where 0 indicates normal gingiva and 3 indicates severe inflammation with marked redness, edema, and a tendency to spontaneous bleeding. The mean GI score per participant was calculated. A lower score reflects healthier gingival conditions.
Measured: At baseline and 2 weeks of mouthwash use
Change in Bleeding on Probing (BOP)
The percentage of sites showing bleeding upon gentle probing was recorded as an indicator of gingival inflammation and bleeding tendency. The presence of bleeding was recorded at each examined site following gentle periodontal probing. BOP was expressed as the percentage of bleeding sites, calculated as the number of sites showing bleeding divided by the total number of sites examined ×100%. Higher percentages indicate greater gingival inflammation.
Measured: At baseline and 2 weeks of mouthwash use
Change in Tongue Coating Index
The tongue dorsum was visually divided into six areas (three anterior and three posterior) according to Winkel's Tongue Coating Index (WTCI). Each area was scored from 0 (no coating), 1 (mild coating), and 2 (thick coating), and the total score (0-12) was calculated as the Tongue Coating Index.
Measured: At baseline and 2 weeks of mouthwash use
Change in salivary bacterial load (qPCR quantification)
Salivary bacterial counts of Porphyromonas gingivalis, Fusobacterium nucleatum, Prevotella intermedia, Eikenella corrodens, and Aggregatibacter actinomycetemcomitans were quantified using real-time PCR (qPCR). Changes in bacterial load (log CFU/mL) between baseline and 2 weeks were compared to assess the antibacterial effect of the mouthwash.
Measured: At baseline and 2 weeks of mouthwash use
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted4 Dec 2025
- Study start5 Sep 2023
- Primary completion5 Dec 2023
- Study completion5 Mar 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for HalitosisStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind
- Who is masked
- Participant, Care provider, Investigator, Outcomes assessor
- Enrolment
- 40 participants (actual)
Sponsor and investigators
- Lead sponsor
- Can Tho University of Medicine and Pharmacy
- Sponsor type
- University, hospital or other
- Responsible party
- Sponsor
- Investigators
- Thuy A.V. Pham, Assoc.Prof., Principal investigator, Can Tho University of Medicine and Pharmacy
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07265102
- Sponsor's protocol ID
- CHXCDO-Halitosis-2022
- Acronym
- CHX+CDO
- Status last verified
- Dec 2025
- First submitted
- 24 Nov 2025
- Last updated
- 22 Dec 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Yes: De-identified data, study protocol, and statistical code will be available upon reasonable request
Publications
Pham TAV, Nguyen NTX. Efficacy of chlorine dioxide mouthwash in reducing oral malodor: A 2-week randomized, double-blind, crossover study. Clin Exp Dent Res. 2018 Oct 23;4(5):206-215. doi: 10.1002/cre2.131. eCollection 2018 Oct.
PubMed 30386642Shinada K, Ueno M, Konishi C, Takehara S, Yokoyama S, Zaitsu T, Ohnuki M, Wright FA, Kawaguchi Y. Effects of a mouthwash with chlorine dioxide on oral malodor and salivary bacteria: a randomized placebo-controlled 7-day trial. Trials. 2010 Feb 12;11:14. doi: 10.1186/1745-6215-11-14.
PubMed 20152022
Study at a glance
From the registry record, last updated by the sponsor on 22 Dec 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- A Randomized Double-Blind Crossover Clinical Trial Evaluating the Efficacy of a Mouthwash Containing Chlorhexidine and Chlorine Dioxide in Patients With Oral Malodor
- ClinicalTrials.gov ID
- NCT07265102
- Acronym / sponsor ID
- CHX+CDO / CHXCDO-Halitosis-2022
- Conditions
- Halitosis
- Keywords
- halitosis, chlorhexidine, chlorine dioxide, mouthwash, volatile sulfur compounds, tongue coating
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 40 participants (actual)
- Lead sponsor
- Can Tho University of Medicine and PharmacyUniversity, hospital or other
- Collaborators
- University of Medicine and Pharmacy at Ho Chi Minh City
- Study start
- 5 Sep 2023 (actual)
- Primary completion
- 5 Dec 2023 (actual)
- Study completion
- 5 Mar 2024 (actual)
- First posted
- 4 Dec 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
Halitosis significantly impacts the quality of a patient's life. This randomized, double-blind crossover trial evaluates a mouthwash containing chlorhexidine (0.01%) and chlorine dioxide (0.05%) compared with placebo. Forty participants rinsed twice daily for 2 weeks, followed by a 2-week washout and crossover. The primary outcomes were volatile sulfur compounds (H₂S, CH₃SH), measured by OralChroma. Secondary outcomes included plaque index, gingival index, bleeding on probing, tongue coating, and salivary bacterial counts (Aa, Pg, Fn, Pi, and Ec).
Study design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Quadruple blind (participant, care provider, investigator, outcomes assessor)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| CHX-CDO Mouthwash | Experimental | Other: CHX 0.01% + CDO 0.05% mouthwashParticipants rinsed with a test mouthwash containing 0.01% chlorhexidine and 0.05% chlorine dioxide. Each participant used 15 mL of the solution twice daily (morning and evening) for 30 seconds over a period of 2 weeks. The mouthwash bottles were identical in appearance to maintain blinding. |
| Placebo Mouthwash | Placebo comparator | Other: Placebo mouthwashParticipants rinsed with a placebo mouthwash containing the same excipients, color, and flavoring agents but without chlorhexidine or chlorine dioxide. Each participant used 15 mL of the placebo solution twice daily for 30 seconds over 2 weeks. |
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (3 listed)
- ≥20 natural teeth
- H₂S >1.5 ng/10ml or CH₃SH >0.5 ng/10ml
- Signed informed consent
Key exclusion criteria (7 listed)
- Systemic disease
- Smoking
- Pregnancy or lactation
- Periodontal pockets ≥4 mm
- Recent antibiotic use (<1 month)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| CHX 0.01% + CDO 0.05% mouthwashAlso: CHX+ CDO mouthwashMouthwash formulation containing chlorhexidine 0.01% and chlorine dioxide 0.05%, prepared by the Department of Pharmacy, University of Medicine and Pharmacy at Ho Chi Minh City. | Other | CHX-CDO Mouthwash |
| Placebo mouthwashAlso: Control mouthwashIdentical placebo formulation matched in flavor, color, and excipients but without active ingredients (CHX or CDO). | Other | Placebo Mouthwash |
Primary outcome
Change in Hydrogen sulfide (H₂S) concentration in breath
Time frame: baseline, immediate post-rinse, 2 weeks
The concentration of hydrogen sulfide (H₂S) in oral breath was measured using the OralChroma™ device. The difference between baseline, immediately after rinsing, and 2 weeks was used to assess the efficacy of the mouthwash in reducing volatile sulfur compounds.
Change in Methyl mercaptan (CH₃SH) concentration in breath
Time frame: Baseline, immediate post-rinse, 2 weeks
The concentration of methyl mercaptan (CH₃SH) in oral breath was measured using the OralChroma™ device. The difference between baseline, immediately after rinsing, and 2 weeks was used to evaluate the short-term and sustained effects of the mouthwash on halitosis.
5 secondary outcomes
Change of plaque index
Time frame: At baseline and 2 weeks of mouthwash use
Change in Gingival Index (GI)
Time frame: At baseline and 2 weeks of mouthwash use
Change in Bleeding on Probing (BOP)
Time frame: At baseline and 2 weeks of mouthwash use
Change in Tongue Coating Index
Time frame: At baseline and 2 weeks of mouthwash use
Change in salivary bacterial load (qPCR quantification)
Time frame: At baseline and 2 weeks of mouthwash use
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 22 Dec 2025.
- Background: PubMed 30386642Pham TAV, Nguyen NTX. Efficacy of chlorine dioxide mouthwash in reducing oral malodor: A 2-week randomized, double-blind, crossover study. Clin Exp Dent Res. 2018 Oct 23;4(5):206-215. doi: 10.1002/cre2.131. eCollection 2018 Oct.
- Background: PubMed 20152022Shinada K, Ueno M, Konishi C, Takehara S, Yokoyama S, Zaitsu T, Ohnuki M, Wright FA, Kawaguchi Y. Effects of a mouthwash with chlorine dioxide on oral malodor and salivary bacteria: a randomized placebo-controlled 7-day trial. Trials. 2010 Feb 12;11:14. doi: 10.1186/1745-6215-11-14.
- Individual participant dataSharing planned: Yes. De-identified data, study protocol, and statistical code will be available upon reasonable request
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Thuy A.V. Pham, Assoc.Prof. principal investigator
Can Tho University of Medicine and Pharmacy
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing CHX 0.01% + CDO 0.05% mouthwash in people with Halitosis, run by Can Tho University of Medicine and Pharmacy at 1 site in Vietnam.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 3 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 22 Dec 2025. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Vietnam. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Change in Hydrogen sulfide (H₂S) concentration in breath (time frame: baseline, immediate post-rinse, 2 weeks). The study lists 2 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT07265102, which also lists 2 linked publications.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 22 Dec 2025.