Effect of scaling and root planing with and without minocycline HCl microspheres on periodontal pathogens and clinical outcomes: A randomized clinical trial

Background: This study tests the effects of scaling and root planing (SRP) versus SRP plus minocycline hydrochloride microspheres (SRP+MM) on 11 periodontal pathogens and clinical outcomes in Stage II-IV Grade B periodontitis participants. Methods: Seventy participants were randomized to receive SRP (n = 35) or SRP+MM (n = 35). Saliva and clinical outcomes were collected for both groups at baseline before SRP, 1-month reevaluation, and at 3- and 6-month periodontal recall. MM were delivered to pockets ≥5 mm immediately after SRP and immediately after the 3-month periodontal maintenance in the SRP+MM group. A proprietary saliva test^* was utilized to quantitate 11 putative periodontal pathogens. Microorganisms and clinical outcomes were compared between groups using generalized linear mixed-effects models with fixed effects and random effects terms. Mean changes from baseline were compared between groups via group-by-visit interaction tests. Results: Significant reduction in Tannerella forsythia, Treponema denticola, Fusobacterium nucleatum, Prevotella intermedia, Parvimonas micra, and Eikenella corrodens were identified at the 1-month reevaluation after SRP+MM. Six months after SRP with a re-application of MM 3 months after SRP, Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, and Eikenella corrodens were significantly reduced. SRP+MM participants had significant clinical outcome reductions in pockets ≥5 mm at the reevaluation, 3- and 6-month periodontal maintenance, and clinical attachment loss gains at the 6-month periodontal maintenance. Conclusion: MM delivered immediately after SRP and reapplication at 3 months appeared to contribute to improved clinical outcomes and sustained decreased numbers of Fusobacterium nucleatum, Prevotella intermedia, Campylobacter rectus, and Eikenella corrodens at 6 months.