The potential effects of probiotic mouth rinse on halitosis in a sample of dental students
| ISRCTN | ISRCTN10448956 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN10448956 |
- Submission date
- 09/06/2025
- Registration date
- 22/06/2025
- Last edited
- 19/06/2025
- Recruitment status
- Recruiting
- Overall study status
- Ongoing
- Condition category
- Oral Health
Plain English summary of protocol
Background and study aims
Halitosis (bad breath) is associated with considerable social embarrassment, especially in younger individuals. This study aims to find out whether probiotics can reduce halitosis and achieve a reduction in certain bacteria.
Who can participate?
Dental students from the College of Dentistry/University of Sulaimani with halitosis
What does the study involve?
The participants will be instructed to use the probiotic mouth rinse for 2 weeks and three samples of saliva will be obtained to assess the effect of the product on certain bacteria. After that, the participants will be divided into two groups based on the severity of their tongue coating. The possible effect of probiotic mouth rinse on halitosis and certain bacteria will be evaluated.
What are the possible benefits and risks of participating?
The probiotic mouth rinse may be beneficial for halitosis with no known risks to health.
Where is the study run from?
University of Sulaimani (Iraq)
When is the study starting and how long is it expected to run for?
December 2024 to December 2025
Who is funding the study?
Investigator initiated and funded
Who is the main contact?
Dr Khadija M Ahmed, khadija.ahmad@univsul.edu.iq
Contact information
Public, Scientific, Principal Investigator
University of Sulaimani
Baxtiary
46002
Iraq
 ORCID ID |
0000-0002-2922-2630 |
|---|---|
| Phone | +964 (0)7701591751 |
| khadija.ahmad@univsul.edu.iq |
Study information
| Study design | Single-center observational cross-sectional study |
|---|---|
| Primary study design | Observational |
| Secondary study design | Cross sectional study |
| Study setting(s) | University/medical school/dental school |
| Study type | Efficacy |
| Participant information sheet | Not available in web format, please use the contact details to request a participant information sheet |
| Scientific title | The effectiveness of probiotic mouth rinse in alleviating halitosis clinically and its impact on three strains of bacteria in a sample of dental students |
| Study objectives | Probiotic mouth rinse could have effects on halitosis clinically and microbiologically. The null hypothesis is that probiotic mouth rinse has no effect in treating halitosis. |
| Ethics approval(s) |
Approved 02/11/2023, The Ethics Committee of the College of Dentistry (University of Sulaimani, Madam Mitterrand Street, Sulaymaniyah, 46001, Iraq; +964 (0)7704522890; dentistry.ethics@univsul.edu.iq), ref: 204/23 |
| Health condition(s) or problem(s) studied | Halitosis |
| Intervention | Participants will be selected from dental students of the college of dentistry with genuine halitosis and coated tongue. Patients will be instructed to use probiotic mouth rinse two times per day and will be instructed not to eat or drink anything and not conduct any oral hygiene activities for at least 1 h. Neither professional prophylaxis nor toothbrushing instructions will be performed during or before the experimental period. Maintenance of this regime will be confirmed at days 1, 7 and 15 of the study . Malodor will be assessed, clinical parameters will be recorded, and the whole stimulated saliva samples will be obtained from all participants at baseline and days 1, 7 and 15 of the study. Organoleptic (OLT) score, area of tongue coating (Ta), thickness of tongue coating (Tt), and malodor assessment will be conducted by a single dentist. The OLT score and tongue coating will be evaluated as the major outcomes. Assessments will be conducted in the morning between 8:00 and 10:00 am. In the 24 h before odour testing, the patients will not be allowed to eat onions, garlic, leeks, and other odorous foods, or to drink alcohol. In the 2 h before testing, the patients also will not be allowed to eat, to drink beverages, to chew gum, or to brush their teeth. The OLT score includes a scale of 0 to 5. The patients closed their mouths for 1 min and then exhaled slowly from their mouths into the clinician’s face from a 10-cm distance. The score will be evaluated as follows: 0 = none, 1 = barely noticeable, 2 = slight but clearly noticeable, 3 = moderate, 4 = strong offensive, and 5 = extremely foul. The reduction of the OLT score will be considered to be effective. The area and thickness of tongue coating will be determined by inspection. Ta will be determined on a scale of 0–3 (0, none visible; 1, less than one-third of tongue dorsum surface covered; 2, less than two-thirds; and 3, more than two-thirds). Tt will be recorded as a score of 0–2 (0, no tongue coating; 1, thin tongue coating: tongue papillae visible; and 2, thick tongue coating: tongue papillae invisible). Then, the tongue coating score (TCS) will be obtained by multiplying Ta by Tt. For the microbiological examination, the prevalence of L. salivarius, periodontopathic bacteria producing volatile sulphur compounds (VSCs), including P. gingivalis, and cariogenic bacteria, including Streptococcus mutans, will be determined by polymerase chain reaction (PCR) and the amount of L. salivarius in the saliva will be determined by real-time PCR. |
| Intervention type | Mixed |
| Primary outcome measure | Halitosis determined clinically using organoleptic (OLT) score and tongue coating score [area of tongue coating (Ta), thickness of tongue coating (Tt)] at baseline day 1, 1 and 2 weeks (day 7 and 15) after administration of the mouth rinse |
| Secondary outcome measures | Strains of bacteria evaluated by examining the whole stimulated saliva using real-time PCR at days 1, 7 and 15 |
| Overall study start date | 21/12/2024 |
| Completion date | 21/12/2025 |
Eligibility
| Participant type(s) | Patient |
|---|---|
| Age group | Adult |
| Lower age limit | 19 Years |
| Upper age limit | 25 Years |
| Sex | Both |
| Target number of participants | 40 |
| Total final enrolment | 35 |
| Key inclusion criteria | 1. Willing to be included in the study 2. Halitosis proven by OLT measure with tongue coating |
| Key exclusion criteria | 1. Those who dislike being part of the study 2. Use of antibiotics in the previous 3 months 3. Systemic illnesses |
| Date of first enrolment | 22/12/2024 |
| Date of final enrolment | 20/12/2025 |
Locations
Countries of recruitment
- Iraq
Study participating centre
Baxtiary
46002
Iraq
Sponsor information
University/education
University of Sulaimani
Baxtiary
46002
Iraq
| Phone | +964 (0)7701591751 |
|---|---|
| khadija.ahmad@univsul.edu.iq | |
| Website | https://univsul.edu.iq/en/ |
"ROR" |
https://ror.org/00saanr69 |
Funders
Funder type
Other
No information available
Results and Publications
| Intention to publish date | 20/11/2025 |
|---|---|
| Individual participant data (IPD) Intention to share | Yes |
| IPD sharing plan summary | Available on request |
| Publication and dissemination plan | The study is planned to be published in a journal with an impact factor |
| IPD sharing plan | The data analyzed during the study period will be available upon request from Dr Khadija M Ahmed (khadija.ahmad@univsul.edu.iq). Dates of availability: after completing the analysis. Consent was obtained from the participant before starting the study. The data collection is confidential, and for transparency and upon reasonable request the analysed data would be available publicly. |
Editorial Notes
10/06/2025: Study's existence confirmed by the Ethics Committee of the College of Dentistry, University of Sulaimani.
