Bifunctional dentifrice: Amorphous polyphosphate a regeneratively active sealant with potent anti-Streptococcus mutans activity.

Objective: In this study we demonstrate that inorganic polyphosphate (polyP) exhibits a dual protective effect on teeth: it elicits a strong antibacterial effect against the cariogenic bacterium Streptococcus mutans and, in form of amorphous calcium polyP microparticles (size of 100-400nm), it efficiently reseals cracks/fissures in the tooth enamel and dentin.

Methods: Three different formulations of amorphous polyP microparticles (Ca-polyP, Zn-polyP and Sr-polyP) were prepared.

Results: Among the different polyP microparticles tested, the Ca-polyP microparticles, as a component of a newly developed formulation of a dentifrice, turned out to be most effective in inhibiting growth of S. mutans. Further studies have shown that it is mainly the soluble polyP, which has a strong antibacterial activity, either given as sodium salt of polyP or formed by partial disintegration of the microparticles via the alkaline phosphatase present in the oropharyngeal cavity. In addition, we demonstrate that the developed toothpaste containing incorporated amorphous polyP microparticles, efficiently reduces dental biofilm formation.

Significance: From our results we conclude that polyP microparticles, if added to toothpaste in an amorphous state, might be beneficial not only for restoring tooth damages but also because they provide a suitable depot of functionally/antibacterially active soluble polyP.