Caseinophosphopeptides and dental protection: Concentration and pH studies

Casein-derived phosphopeptides (CPP) can protect teeth from acids produced by bacteria causing dental caries or directly from acidic foods and beverages causing dental erosion. Neither the CPP concentrations required for protection nor the effective pH range has been published and the protective mechanism is still open to debate. Using experimental protocols mimicking practical situations in which CPP and acid were present together in a hydroxyapatite model system, or in which excess CPP was removed before acid exposure and also using either Ca-saturated CPP or Ca-reduced CPP, we found that in all cases protection was 50–60% at pH 4.2. Protection increased exponentially with CPP concentration to about 10.0 mg/ml as measured in mixtures before acid addition, with little further improvement above that. Most of the protection was achieved at a more economical 4.0–6.0 mg/ml. The extent of protection was almost constant over the pH range 2.5–4.5. Our findings suggested a mechanism involving the formation of a protective coat of CPP over the mineral particle surfaces.