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.

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.

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.

The study population consisted of adults aged 18-55 years diagnosed with generalized periodontitis and presenting with complaints of halitosis who sought care at the Batman University Faculty of Dentistry Clinical Application Center. A total of 150 patients were screened, and 101 individuals who met the inclusion criteria were enrolled in this prospective cohort study.

Individual participant data will not be shared due to privacy considerations and institutional data protection policies.