Xylitol

Xylitol is initially taken up by the microorganism and accumulates intracellularly. Accumulated xylitol is transported into an energy-consuming cycle, or the inducible fructose transport system. It is converted to non-metabolizable, toxic xylitol-5-phosphate via phosphoenolpyruvate: a constitutive fructose phosphotransferase system by S. mutans. This metabolic process of xylitol, without the gain of any energy molecules, results in the development of intracellular vacuoles and cell membrane degradation. S. mutans dephosphorylates xylitol-5-phosphate and expels it from the cell, in which requires energy consumption. This ultimately leading to starving of microorganism and growth inhibition. Long-term exposure to xylitol can cause microorganisms to develop resistance to xylitol. This clinically beneficial selection process creates xylitol-resistant mutans strains that are less virulent and less cariogenic than their parent strains. Xylitol also increases the concentrations of ammonia and amino acids in plaque, thereby neutralizing plaque acids. A study suggests that xylitol may also promote remineralization of deeper layers of demineralized enamel by facilitating Ca2+ and phosphate movement and accessibility.