Background: Bad breath is often caused by periodontitis and/or tongue coating. This study followed the impact of initial periodontal therapy on several halitosis-related outcome variables over a 6-month period. Organoleptic ratings are often uncomfortable for the patient and have several disadvantages. They are, for instance, influenced by external parameters (e.g., food intake and cosmetics) and need to be calibrated among researchers worldwide. A second aim was to evaluate the reliability of saliva incubation as an in vitro indirect test for breath recording.

Methods: In this double-blind, randomized, medium-term, parallel study 45 moderate periodontitis patients without obvious tongue coating were enrolled. Besides a one-stage, full-mouth disinfection and oral hygiene improvement (including daily tongue scraping), patients were instructed to rinse daily for 6 months with one of the following products (randomly allocated): chlorhexidine (CHX) 0.2% + alcohol, CHX 0.05% + cetyl pyridinium chloride (CPC) 0.05% without alcohol (a new formulation), or a placebo solution. At baseline and 3 and 6 months, a series of parameters were recorded including: concentration of volatile sulfide compounds (VSC), tongue coating, and an estimation of the microbial load (at anterior and posterior parts of the tongue, saliva, dental plaque). The intraoral VSC ratings were compared to in vitro VSC recordings and organoleptic evaluations of the headspace air from 1 and 2 hours incubated saliva (0.5 ml, 37°C, anaerobic chamber).

Results: Even though the initial VSC values were not high (±90 ppb with only 18 patients revealing more than 100 ppb), significant (P <0.05) reductions could be achieved in the CHX and CHX + CPC group, and to a lower extent in the placebo group (P = 0.10). Tongue scraping resulted in a significant reduction (P ≤0.05) of the tongue coating up to month 6 in the placebo and CHX + CPC group, but not in the CHX group (confusion due to staining). The CHX and CHX + CPC group showed, in comparison to baseline, significant (P <0.001) reductions in the number of anaerobic species in the supragingival plaque, in the saliva, and on the anterior part of the tongue. For the posterior part of the tongue the microbial changes remained ≤0.3 log values (P >0.05). For the placebo group, the microbial changes never reached a level of significance (≤0.3 log values). A strong correlation was found between the intraoral VSC ratings and the 1-hour (r = 0.48, P <0.0001; r = 0.54, P = 0.0003 for baseline data only) and 2-hour (r = 0.43, P <0.0001) VSC production of incubated saliva. The latter also correlated very strongly (r = 0.71) with the number of anaerobic species in the saliva. The VSC values and organoleptic ratings of the incubated saliva also correlated strongly with each other (r = 0.64 for 1-hour and 0.73 for 2-hour incubation).

Conclusions: The results of this study indicate that in patients with moderate periodontitis, initial periodontal therapy including tongue scraping did not have a significant effect on the microbial load of the tongue and had only a weak impact on the VSC level, except when combined with a mouthrinse. Saliva incubation can be used as an indirect way to score breath odor. It offers simplicity, objectivity, and is less invasive. J Periodontol 2005;76:705-712.