In vitro study on dental erosion provoked by various beverages using electron probe microanalysis.

Tooth erosion is often based on chemical processes, among others the use of soft drinks or diverse beverages. The aim of this in vitro study was to analyse the erosive potential of different acidic beverages. Over a time span of 6 hours, dental slices (n=6 slices per tooth) from fully retained wisdom teeth were incubated with different beverages (coca cola, ice tea with lemon, apple juice and white wine). The controls were incubated with a 0.9% sodium chloride solution under the same conditions (37 degrees C, humidified atmosphere of 5% CO2 and 95% air). The quantitative elementary analysis for calcium, phosphorus, oxygen and other trace elements in the dental slices in various depths ranging from 5 to 50 microm was carried out using an electron probe micro-analyser (Jeol JXA 8900RL). A beverage-induced loss of minerals, particularly of the 2 main components calcium and phosphorus, especially in the uppermost layers of the enamel down to a depth of 30 microm could be observed. In the depth of 10 microm, the following total mineral loss could be determined: white wine (16%), coca cola (14.5%), apple juice (6.5%) and ice tea with lemon (6.5%). A direct correlation between the loss of minerals and the pH value of the beverages was not observed, because of the buffering effect of the drinks. The conversion of the weight percentages from the chemical analysis of Ca and P to their atomic percentages showed that during erosion the 2 main components were not dissolved in significantly different percentages. In this study the erosive potential of the tested soft drinks and other beverages could be demonstrated. However, it must be considered that numerous modifying factors influence the enamel surface, so an extrapolation from the in vitro study to an in vivo situation can only be applied with caution.