A key step in the remineralization process is the recovery of plaque pH to a level that is higher than critical pH. The factors that affect this include the buffering capacity of saliva, whether fermentable carbohydrate remains in the mouth, and the diffusion of acids from plaque into saliva or teeth. It is also influenced by the production of bases in plaque. Ammonia from the deamination of amino acids and breakdown of urea in saliva are examples of reactions that make plaque pH less acidic. These bases are important to neutralize acid when carbohydrate intake is moderate.17 The rise in pH to a less acidic level may also be assisted by the removal of acids by bacteria. For example, the bacterial genus Veillonella use lactate as a substrate, metabolizing it to less acidic products, such as propionic acid and acetic acid (Figure 3).7
