C.L.: Characterization of Components of Dental Materials and Components of Tooth Structure by Differential Thermal Analysis

Differential thermal analysis (DTA) has been used to characterize a variety of dental materials and the components of tocth structure. The technic is useful for the rapid comparison of similar materials, quality control, measurement of melting ranges, and the study of reactions occurring at elevated temperatures. Differential thermal analysis (DTA) mea-sures the heat-energy changes associated with physical or chemical transformations as a function of temperature or time. Al-though the principle of DTA was suggested by LeChatelier ' in 1888, this technic has found increasing acceptance only during the last ten years with the availability of compact commercial units. Experimentally, the sample and a reference material are heated at a uniform rate, and the tempera-ture difference between sample and ref-erence material (AT) is measured as a function of sample temperature. The num-ber, shape, and position of the various endothermic and exothermic peaks with reference to the furnace temperature can be used for the qualitative identification of a substance. It can also be used for the determination of the physical properties of the material such as the melting, fusion or boiling point, or crystalline-structure inversions. Chemical reactions such as de-hydration, decarboxylation, decomposition, This investigation is part of the dental researc