Halitosis: A Prospective Cohort Study Comparing Periodontal Debridement with Tongue Cleaning, Denture Biofilm Management, and Restorative Maintenance

Background: Halitosis in elderly dental patients is rarely attributable to a single etiology; tongue coating, periodontal inflammation, denture biofilm, and reduced salivary flow may coexist and modify treatment response. We compared three procedure pathways and examined whether tongue-coating reduction mediates procedure-related improvement. Methods: A prospective cohort of 94 patients aged 65 years or older was assigned by dominant indication to periodontal debridement with tongue cleaning (PDT, n = 33), denture biofilm management (DBM, n = 31), or restorative/prosthetic maintenance (RPM, n = 30). This was a single-center, nonrandomized prospective cohort study; assignment followed the dominant clinical indication rather than randomization. All clinical assessments were made by a single examiner who was masked to the formal procedure-group assignment; masking was partial because the clinical picture at follow-up could sometimes reveal the care delivered. The primary outcome was percentage reduction in volatile sulfur compound (VSC) concentration at 8 weeks. Secondary outcomes included organoleptic score, HALT, OHIP-14, tongue-coating index, denture plaque index, and a composite clinical response (≥30% VSC reduction plus ≥ 1-point organoleptic improvement plus ≥ 8-point HALT improvement). Linear mixed-effects, multivariable regression, and bootstrap mediation analyses were performed. Results: All three procedures reduced VSC at 8 weeks, but PDT produced the largest absolute reduction (−102.6 ± 20.2 ppb) and the highest composite response rate (57.6%), versus 9.7% in DBM and 3.3% in RPM (p < 0.001). Adjusted analyses showed PDT improved VSC reduction by 22.8 percentage points and DBM by 11.7 percentage points relative to RPM. Tongue-coating reduction mediated 29.5% of the PDT effect and 35.6% of the DBM effect. Xerostomia and reduced salivary flow attenuated the response in DBM and RPM but not in PDT. Conclusions: Periodontal debridement with tongue cleaning was the most effective procedure pathway for elderly halitosis. Tongue-coating reduction was a meaningful, though statistically rather than experimentally established, mediator of treatment benefit, supporting an oral-ecological framework for managing geriatric oral malodor that warrants confirmation in randomized studies.