ABSTRACT
Considering the high prevalence of dental caries, dentists and researchers are searching for restorative materials that are similar to tooth structure and are acceptable from biological point of view. The purpose of this study was to investigate the thermal behavior of a filled tooth with different restorative materials. Modeling was designed using solid ambient work software using the actual measurements of a typical human maxillary second premolar tooth dimensions. A class II [MOD] cavity was prepared and restored with amalgam and composite, with and without using Glass Ionomer as base material. Finally, the restored and non-restored tooth behavior was analyzed under thermal exposure when exposed to hot liquid. A three-dimensional finite-element analysis was conducted using ANSYS soft ware. Analysis of data revealed that placing base material under the amalgam fillings can decrease the maximum pulp temperature by about 43% compared to restorations without base. While, the temperature reduction was only about 17% in composite restorations. It was also found that the base material used under the amalgam fillings can protect the pulp from sudden temperature changes because of considerable time lapse between the application of thermal load and a change in pulp temperature. This time delay is greater in the composite restorations compared with amalgam by about 10% and the maximum time delay was found in sound tooth. The closest temperature profile to sound tooth is found in restorations with composite resin filled over a base material. This study demonstrated that the base material can protect the pulp from sudden temperature changes; likewise, it can decrease the maximum temperature in the pulp chamber/canal