A study by Escribano, et al published in the Journal of Clinical Periodontology eval­uated the clinical and micro­­biological efficacy of a 0.05% chlorhexidine and  0.05% cetylpy­ridinium chlo­­­ride mouth rinse for use in supportive perio­dontal care (SPC) in pa­tients who did not practice adequate plaque control. 

The study was a randomized, double-blinded, pla­cebo-controlled clinical tri­al in­volving patients with moderate to severe chronic periodontitis un­der SPC with inadequate plaque control (Turesky index > 1). Following su­pragingival prophylaxis and oral hy­giene reinforcement, the subjects rinsed twice a day for 3 months with the test or placebo solutions, in addition to conventional hy­giene. Pri­mary clinical outcome var­iables included plaque and gingival indices; periodontal and microbiological vari­­ables were studied as secondary outcomes. Of the 47 patients that participated, 22 were in the placebo group and 25 were in the test group. After 3 months, plaque levels in­creased in the placebo group, and diminished in the test group (P < .001). Similar effects were found for bleeding on probing. The other clinical parameters did not show significant differences. However, there were significant intergroup reductions in subgingival counts of Fusobac­terium nucleatum and Prevo­tella intermedia, and a de­crease of the total bacterial counts in saliva. The study concluded that the chlor­hexidine mouth rinse de­monstrated efficacy in re­ducing plaque and gingivitis, as well as in de­creasing the microbial load in saliva and the gingival sulcus.