A novel antimicrobial and remineralizing toothpaste containing CaCl₂/chitosan microspheres

To investigate the feasibility of exploiting amorphous calcium phosphate (ACP) formed in situ from chitosan calcium microspheres and phosphate ions in water during brushing for caries control.

A prototype toothpaste, namely Chi-ACP paste, was specially formulated containing CaCl₂/chitosan microspheres. The efficiency of Chi-ACP paste for remineralization on human tooth enamel was evaluated via an in vitro pH cycling approach. After 15 demineralization/remineralization cycles, the treated teeth were analyzed using scanning electron microscope (SEM) /energy dispersive X-ray spectroscopy (EDX), and polarized light microscope (PLM).

EDX analysis showed the treated enamel in the Chi-ACP paste group had statistically significantly higher calcium content and Ca/P weight ratios than those in the negative control group, while the MI plus group had a slightly higher Ca content and a slightly higher Ca/P weight ratio. PLM analysis revealed that the Chi-ACP paste group had a larger remineralization band in treated enamel than the negative control group, although there was no statistically significant difference on the demineralization depths in the enamel among the three groups.

Antibacterial chitosan could be used to encapsulate CaCl₂ and then formulated into toothpaste for caries control through in-situ formed amorphous calcium phosphate (ACP) during brushing.