Changes in Bad Breath and Olfactory Function After Extraction of Carious Teeth

November 9, 2026 updated by: Rojdan Ferman GÜNEŞ UYSAL, Batman University

The Effect of Dental Caries on Halitosis Awareness and Olfactory Functions

This study aims to evaluate changes in halitosis and olfactory function in adults with advanced dental caries requiring tooth extraction.

A total of 80 adult patients aged 18-65 years with one or more teeth indicated for extraction due to advanced dental caries will be included. Tooth extractions will be performed under local anesthesia using an atraumatic technique as part of routine dental care. The extraction sockets will be allowed to heal by secondary intention.

Assessments will be performed before tooth extraction and 21 days after the last extraction. Halitosis will be evaluated by a single trained and blinded examiner using the organoleptic scoring method (OLS). Participants will also rate their perceived halitosis using a visual analog scale (VAS).

Olfactory function will be assessed using the Sniffin' Sticks test, which consists of three components: odor threshold, odor discrimination, and odor identification. The scores of these three tests will be combined to calculate the total TDI score.

The preoperative and postoperative results will be compared to investigate changes in halitosis and olfactory function following the removal of carious teeth.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Observational

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
80

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

18 years to 65 years (Adult, Older Adult)

Accepts Healthy Volunteers

No

Genders Eligible for Study

All

Sampling Method

Non-Probability Sample

Study Population

The study population consists of 80 adults aged 18-65 years with one or more teeth indicated for extraction due to advanced dental caries. Participants are systemically healthy, non-smokers, and have healthy periodontal tissues or have completed periodontal treatment before enrollment. Both male and female participants are included. Tooth extractions are performed under local anesthesia using an atraumatic technique as part of routine clinical care. Halitosis and olfactory function are assessed before tooth extraction and 21 days after the last tooth extraction. Participants who do not meet the eligibility criteria are excluded from the study.

Description

Inclusion Criteria:

Adults aged 18-65 years. Patients with one or more teeth indicated for extraction due to advanced dental caries.

Systemically healthy individuals. Non-smokers. Individuals with healthy periodontal tissues or those who have completed periodontal treatment before enrollment.

Exclusion Criteria:

History of loss of smell or changes in olfactory function within the two weeks preceding the olfactory assessments and tooth extraction.

Use of antibiotics or anti-inflammatory medications for more than 7 consecutive days within the preceding 6 weeks.

Presence of an upper respiratory tract infection at the time of assessment. History of COVID-19 infection. Pregnancy. Lactation. Traumatic tooth extraction or extraction procedures requiring flap elevation. Development of alveolar osteitis (dry socket) during the postoperative follow-up period.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Observational Models: COHORT
  • Time Perspectives: PROSPECTIVE

Cohorts and Interventions

Group / Cohort

Group / Cohort

A group or subgroup of participants in an observational study that is assessed for biomedical or health outcomes.
Adults Undergoing Extraction of Carious Teeth

This cohort consists of adults aged 18-65 years who underwent extraction of one or more teeth due to advanced dental caries as part of routine clinical care. Tooth extractions were performed under local anesthesia using an atraumatic technique, and the extraction sockets were allowed to heal by secondary intention.

Participants underwent assessments of halitosis and olfactory function before tooth extraction and 21 days after the last extraction. Halitosis was evaluated using an organoleptic scoring method and a patient-reported visual analog scale (VAS). Olfactory function was assessed using the Sniffin' Sticks test, including threshold, discrimination, and identification components (TDI score).

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Change in Organoleptic Score (OLS) from Baseline to Follow-up
Time Frame: At baseline (before tooth extraction) and 21 days after the last tooth extraction.

Halitosis will be assessed by a single trained and blinded examiner using the organoleptic scoring method (OLS). Participants will be instructed to keep their mouths closed, breathe through their noses, and then exhale through their mouths. The examiner will assess the odor of the exhaled breath using a 6-point scale ranging from 0 to 5, where 0 indicates no detectable odor and 5 indicates extremely strong odor. Changes in OLS scores between baseline (before tooth extraction) and follow-up will be evaluated.
At baseline (before tooth extraction) and 21 days after the last tooth extraction.

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in Patient-Perceived Halitosis Severity (VAS) from Baseline to Follow-up
Time Frame: At baseline (before tooth extraction) and 21 days after the last tooth extraction.

Participants will assess their perceived halitosis severity using a 10-point visual analog scale (VAS), ranging from 0 (no perceived bad breath) to 10 (extremely severe bad breath). Changes in VAS scores between baseline (before tooth extraction) and follow-up will be evaluated.
At baseline (before tooth extraction) and 21 days after the last tooth extraction.
Change in Olfactory Function (Sniffin' Sticks TDI Score) from Baseline to Follow-up
Time Frame: At baseline (before tooth extraction) and 21 days after the last tooth extraction.

Olfactory function will be assessed using the Sniffin' Sticks test, consisting of three components: odor threshold (T), odor discrimination (D), and odor identification (I). The threshold test evaluates the lowest odor concentration that participants can detect. The discrimination test assesses the ability to distinguish between different odors, while the identification test evaluates the ability to identify familiar odors from multiple-choice options. The scores of the three components will be summed to obtain the total TDI score. Changes in total TDI scores between baseline and follow-up will be evaluated.
At baseline (before tooth extraction) and 21 days after the last tooth extraction.

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Batman University

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
May 6, 2026

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
May 27, 2026

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
July 1, 2026

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
November 9, 2026

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 9, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
November 13, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
November 13, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
November 9, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
November 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • 2026/02-03

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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