Antimicrobial effects of a new brushing solution concept on a multispecies in vitro biofilm model growing on titanium surfaces

Objectives: To evaluate the antibiofilm and antibacterial effects of a new brushing solution concept, in a validated peri-implant biofilm model. Materials and Methods: A multispecies in vitro biofilm model, including Streptococcus oralis, Actinomyces naeslundii, Veillonella parvula, Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis and Fusobacterium nucleatum, was used. To evaluate the antibiofilm capacity, titanium discs (Ti-SLA) were immersed in 1 ml of the tested solution (one tablet dissolved in warm water) for 2 min, prior and every 24 h during a 3-day biofilm development. Negative (water) and positive (0.12% chlorhexidine/0.05% cetylpyridinium chloride mouth rinse) controls treated discs were run in parallel. To evaluate the antibacterial effects, planktonic cells and 72-h biofilms on sterile Ti-SLA discs were exposed (2 min) to the mentioned treatments. Biofilm structure was analysed by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Bacterial load was measured by quantitative polymerase chain reaction and by culture in planktonic cells. Results: The tested product showed antibiofilm effects, impacting on the 48-h and 72-h biofilm thickness and significantly reducing viability of all bacterial species, except A. actinomycetemcomitans. Antibacterial effects were observed against the six bacterial species in planktonic state and in 72-h biofilms, especially for F. nucleatum and A. actinomycetemcomitans. Conclusion: The tested brushing solution demonstrated antibacterial and antibiofilm properties, mainly against the peri-implant pathogens included in the validated in vitro biofilm model used.