Comparative Analysis of Subgingival Microbial Profiles in Patients with Periodontal Disease with and Without Depressive Comorbidity

Background: Full-mouth disinfection (FMD) has been proposed as an effective non-surgical approach for the management of periodontitis; however, its clinical and microbiological outcomes in patients with depressive comorbidity remain insufficiently explored. Methods: This prospective study included 80 patients diagnosed with stage II periodontitis, allocated into two groups based on the presence or absence of depressive disorder. All participants underwent standardized FMD. Clinical parameters, including bleeding on probing and plaque index, together with subgingival bacterial load (total bacterial load, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia), were assessed at baseline and 12 weeks post-treatment using quantitative polymerase chain reaction. Microbiological data were log10-transformed prior to statistical analysis. Results: Significant reductions in both clinical and microbiological parameters were observed following treatment in both groups. Improvements in bleeding on probing and plaque index were accompanied by a marked decrease in total bacterial load and in the targeted periodontal pathogens. Patients with depressive disorder exhibited a higher baseline microbial burden; however, post-treatment reductions were comparable between groups. Moderate positive correlations were identified between total bacterial load and clinical parameters. Conclusions: FMD was associated with substantial short-term improvements in both clinical and microbiological outcomes in patients with stage II periodontitis. Depressive comorbidity did not appear to adversely influence treatment response. These findings support the role of biofilm control as a central component of periodontal therapy across different patient profiles