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

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.

• Scaling and Root Planing (SRP) (Procedure): Full-mouth non-surgical periodontal therapy consisting of scaling and root planing (SRP) performed using ultrasonic scalers and hand curettes. The therapy is administered over three sessions spanning three weeks to achieve thorough debridement of subgingival dysbiotic biofilm and calculus, alongside tongue cleaning instruction.

Primary outcomes

• Change in Total TDI Score [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.
• Change in Total Volatile Sulfur Compound (tVSC) Levels [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).

Sex: All, ages: 18 Years to 55 Years

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.

• Mustafa Baran, Asst. Prof., Principal investigator, Batman University