Effect of Thermal Stresses on the Mechanism of Tooth Pain

• Hot and cold loadings on a human intact premolar were modeled by finite element.
• Cold beverages led to adverse effects on the intact tooth.
• Changes in stress (strain) were sensed earlier than temperature in the tooth.
• Evidence indicated that pain might be sensed by nonthermal mechanism.

IntroductionDaily hot and cold thermal loadings on teeth may result in structural deformation, mechanical stress, and pain signaling. The aim of this study was to compare the adverse effects of hot and cold beverages on an intact tooth and, then, to provide physical evidence to support the hydrodynamic theory of tooth pain sensation mechanism.MethodsThree-dimensional finite element analysis was performed on a premolar model subjected to hot and cold thermal loadings. Elapsed times for heat diffusion and stress detection at the pulp-dentin junction were calculated as measures of the pain sensation.ResultsExtreme tensile stress within the enamel resulted in damage in cold loadings. Also, extreme values of stress at the pulpal wall occurred 21.6 seconds earlier than extreme temperatures in hot and cold loadings.ConclusionsThe intact tooth was remarkably vulnerable to cold loading. Earlier changes in mechanical stress rather than temperature at the pulp-dentin junction indicate that the dental pain caused by hot or cold beverages may be based on the hydrodynamic theory.