Food that we eat is classified as follows on the basis of its cariogenicity activity: Cariogenic foods: These are foods that contain fermentable carbohydrates, which in contact with micro-organisms in the mouth can cause a drop in salivary pH to 5.5 or less and stimulate caries process.  Examples are foods rich in simple carbohydrates. NOTE:  When the pH of saliva falls below 5.5 dental caries occur...