The Effect of Saliva on Plaque pH in vivo

The impact of saliva on plaque pH in vivo, following exposure to a sucrose substrate, was measured in ten caries-resistant (CR) and ten caries-susceptible (CS) subjects under varying conditions of salivary access. When the plaque was denied access to saliva, the pH minima reached by the CR and CS groups were comparable. As the access to saliva was increased, the observed pH minima increased to a significantly greater degree in the CR subjects than in the CS subjects. This demonstrates the major role that saliva plays in modifying plaque pH, especially in caries-resistant people.