[Influence of teas with fruit aroma and ice teas on pH and buffer capacity of saliva]

A number of teas with fruit aroma and ice teas has been tested on erosivity. The teas with a fruit taste have at their drinking temperature (45 degrees C) a pH between 6.2 to 7.4. Even teas with a citron or citrus flavour are neutral. The most acidic tea tested has a mango-peach-taste, but contains no buffer system. After mixing 1 ml of total saliva up to 10 ml tea or by rinsing the oral cavity with tea the pH of oral fluid was hardly lowered (minimum 6.3). In contrast, ice teas are rather acidic (pH < 4) and have a strong buffer capacity. Rinsing the oral cavity with 5 ml ice tea resulted in a decrease of the pH of the oral fluid to 4.1-4.9. However, within 2 minutes the pH in the oral fluid was already increased to 5.9-7.1 and after 5 minutes to 6.3-7.1. In other words, the teas with fruit aroma, based on organic taste components do not have an erosive potential. On the other hand, ice teas decrease the pH of the oral fluid drastically to a level that they become erosive. Therefore, from a dental point of view, teas with only a taste of fruit can be advised to replace drinking of soft drinks, but ice teas not.