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

Completed

Conditions

Study Type

Observational

Enrollment (Actual)

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

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
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

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

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.

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)

May 6, 2026

Primary Completion (Actual)

May 27, 2026

Study Completion (Actual)

July 1, 2026

Study Registration Dates

First Submitted

November 9, 2026

First Submitted That Met QC Criteria

November 9, 2026

First Posted (Actual)

November 13, 2026

Study Record Updates

Last Update Posted (Actual)

November 13, 2026

Last Update Submitted That Met QC Criteria

November 9, 2026

Last Verified

November 1, 2026

More Information

Terms related to this study

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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