Statistical analysis of salivary pH changes after the intake of black tea and yerba maté supplemented with sweeteners.

Many studies have demonstrated the effect of various beverages on hard tissues of the mouth. Sugar consumption has also been avoided because it is associated with caries activity, and artificial sweetener research has been promoted. In this paper, data about the buffer capacity of black tea and yerba mate supplemented with sugar or one of two artificial sweeteners (Barny diet and NutraSweet) were examined. Salivary pH variations after the ingestion of both infusions were statistically analysed. A factorial design of four variables (Infusion, Sweetener, Concentration and Time) and their effects were considered independently and combined. The addition of sucrose lowered the pH of the infusions while black tea showed a greater buffer capacity than yerba mate. Significant differences (p < 0.0001) were obtained when salivary pH values were compared between infusions supplemented with sugar or artificial sweeteners. When a factorial design was used to examine differences between Barny diet and NutraSweet, no significant two- or three-way interactions could be observed. This statistical analysis showed a small significant variation in salivary pH after the ingestion of black tea or yerba mate with sugar but not with artificial sweeteners at the recommended concentrations.