In the current study we tested the hypothesis that new 0.05% Cetylpyridinium chloride (CPC) mouthrinse formulations containing 0.12% or 0.03% chlorhexidine digluconate (CHX): 1) yield similar or better clinical results regarding the inhibition of de novo plaque growth compared to those achieved with an already marketed 0.12% CHX mouthrinse (Perio-Aid Treatment without alcohol. Dentaid, Spain), 2) reduce the side effects caused by the marketed 0.12% CHX formula and 3) that these mouthrinses have no negative microbiological effects, and they control total bacterial loads.