Antimicrobial Activity of an Innovative Chlorhexidine-Free Children’s Mouthwash Against Beneficial and Pathogenic Oral Microorganisms

The aim of the present study was to evaluate the in vitro antimicrobial efficacy of an experimentally developed chlorhexidine-free children’s mouthwash against selected beneficial and pathogenic oral microorganisms. The antimicrobial activity of individual components and combined mouthwash formulations was assessed using agar diffusion, direct-contact tests, synchronous cultivation and time-kill assays with mixed microbial suspensions and donor-derived dental plaque. The antimicrobial effect was strain-dependent: Tannerella forsythia and Prevotella intermedia showed the highest resistance, whereas Fusobacterium nucleatum and Streptococcus salivarius were more susceptible to the tested components. The prototype formulation demonstrated substantial antimicrobial activity against all tested microorganisms. In the direct-contact test, Sample 1 achieved a 57.22 % reduction in viable cells after 90 s of exposure in the mixed pathogen population, compared with 67.91 % for Eludril classic® and 33.90 % for the placebo formulation. The overall bacterial death-rate constant of Sample 1 was lower than that of the chlorhexidine-containing reference product but remained markedly higher than that of the placebo. The tested multicomponent chlorhexidine-free formulation exhibited relevant antimicrobial activity against planktonic and biofilm-associated oral microorganisms, supporting its potential as a well-tolerated adjunct for pediatric preventive oral care.