Comparative study of heat release of various cement base materials during their setting.

An ideal cement base material in order to protect the pulpal tissue from several external irritations (microbial, mechanical, thermal, galvanic and osmotic irritations) must present the following requirements: to attach or bond to the residual dentin, to be biocompatible, to present suitable physicomechanical, antimicrobial and optical properties, to be color stable, easy to use and rapid to set. Thermal phenomena developed during the mixing and setting are a factor influencing the biocompatibility properties of these materials. Cement base materials are used under various types of filling materials (amalgams, composite resins, gold and porcelain inlays) and are placed in contact with the dentin that contains exposed dentinal tubules. The purpose of this study was to investigate the possible exothermic reaction of these materials and to measure the developing temperatures for a time period from their mixing up to the completion of their setting. We studied the following types of cement base materials: a) Zinc oxide eugenol cement, b) Zinc phosphate cement, c) Zinc polycarboxylate cement and d) Glass ionomer cement both light- and self-cured. From the obtained results we observed that ZOE cements developed the lowest temperatures ranging from 32.8 degrees C to 37 degrees C, while Zinc phosphate cements developed the highest temperatures ranging from 44.4 degrees C to 52 degrees C. The other two types of materials Zinc polycarboxylate and Glass ionomer cements developed biocompatible temperatures ranging from 38 degrees C to 40.8 degrees C, which usually do not cause deteriorations and harms to the pulp. We concluded that the ZOE cements presented the best thermal behaviour followed by Zinc polycarboxylate and Glass ionomer cements. Hence, these materials can be safely used without causing any pulpal response.