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OpenTrials
Completed

NCT Number: NCT07424300

Olfactory Function and Oral Malodor in Periodontitis Before and After Periodontal Therapy

This prospective cohort study investigated the relationship between oral malodor and olfactory function in adults with generalized periodontitis. A total of 101 patients were evaluated before and after routine nonsurgical periodontal therapy. Volatile sulfur compound (VSC) levels and psychophysical olfactory performance using the Sniffin' Sticks test (TDI score) were measured at baseline and one week after completion of three sessions of scaling and root planing (SRP). The study aimed to determine whether reduction of oral inflammation and halitosis is associated with improvement in olfactory performance.

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Key information

Age range

18 year–55 year

Sex eligibility

All sexes

Study type

Observational

Primary location

Batman University

Merkez, Batman, 72040, Turkey (Türkiye)

About this study

Generalized periodontitis is a chronic inflammatory disease associated with increased production of volatile sulfur compounds (VSCs), contributing to halitosis. Elevated intraoral malodor may interfere with olfactory perception through masking effects and inflammatory mechanisms.

Participants diagnosed with generalized periodontitis and complaining of halitosis underwent routine nonsurgical periodontal therapy consisting of three sessions of scaling and root planing performed at one-week intervals. Olfactory function (threshold, discrimination, identification; total TDI score) and total VSC concentrations were assessed at baseline (prior to first session) and one week after completion of the third session.

The study evaluated changes in chemosensory function and halitosis parameters following periodontal therapy and analyzed correlations between baseline VSC levels and olfactory performance.

Who can participate

Healthy volunteers accepted: No

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Inclusion Criteria:
  • Adults aged 18-55 years
  • Diagnosis of generalized periodontitis
  • Complaint of halitosis
  • At least 15 natural teeth

Exclusion criteria

  • Self-reported smell loss or change within 2 weeks prior to baseline
  • Antibiotic or anti-inflammatory drug use for more than 7 days within the previous 6 weeks
  • Presence of upper respiratory tract infection
  • Unrestored advanced dental caries
  • History of COVID-19 infection
  • Pregnancy

Smoking was not an exclusion criterion.

Treatment and study plan

Primary outcomes

  1. Change in Total TDI Score

    Time frame: Baseline to 1 week after completion of third SRP session (approximately 4 weeks total)

    Change in psychophysical olfactory performance measured by the Sniffin' Sticks Test (Threshold-Discrimination-Identification composite score).

    The Sniffin' Sticks Test total TDI score ranges from 1 to 48, calculated as the sum of:

    • Odor Threshold (1-16).
    • Odor Discrimination (0-16).
    • Odor Identification (0-16).

    Higher scores indicate better olfactory function.

  2. Change in Total Volatile Sulfur Compound (tVSC) Levels

    Time frame: Baseline to 1 week after completion of third SRP session

    Change in total volatile sulfur compound (tVSC) concentration measured using the OralChroma portable gas chromatograph device.

    tVSC levels are reported in parts per billion (ppb). Higher values indicate greater halitosis severity (worse outcome).

Sponsors and collaborators

Lead sponsor

Batman University

Other

Registry information

Official study title

Bidirectional Relationship Between Oral Malodor And Olfactory Function In Generalized Periodontitis: A Prospective Cohort Study Evaluating Changes After Nonsurgical Periodontal Therapy

Important dates

Study start
2024
Primary completion
2025
Study completion
2025
First posted
Feb 20, 2026
Registry last updated
Feb 25, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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