The comparison between effect of Kefir, Yoghurt and Soy milk on the enamel microhardness

The popularity of dairy drinks such as Yoghurt and kefir in world and especially in Iran has led to their daily consumption. Since the type of consumable foods could effect on erosion, this research was done to compare the effect of Kefir, Yoghurt and Soy milk on permanent enamel microhardness.
In this in-vitro study 30 extracted permanent teeth with no erosion and caries was chosen. Enamel blocks were made and then divided into three groups of ten. Then Vickers microhardness of each group measured before soaking the samples in the drinks. After samples soaking in its proper drinks (Kefir, Yoghurt and Soy milk) the microhardness of each group measured again. Analysis of variance used for comparing the microhardness of each group and after analysis of variance, tukey HSD was used and significant level was considered as 0.05.
Evaluation was made on 30 samples on 3 groups of 10 members. Difference of microhardness was -4.98±8.31 for soy milk and -19.35±13.38 for yoghurt drink and -33.54±19.54 for kefir. (p Based of the findings of this study, the maximum decrease of microhardness was related to kefir and the minimum was related to soy milk.