In the present study two silane adhesive agents (Silicoup, Heraeus/Kulzer, and Monobond-S, Vivadent) and one type ceramic (VITA VKM 68) and their interface reactions were tested by thermo-analysis. The ceramic powder is thermally inactive. Using the two different silane solutions with the same ceramic type different thermical characteristics were found despite the same base material (gamma-methacryloxi-propyl-trimethoxi-silane). This can probably be attributed to the different configurations of the polycondensates.