In this study, the thermomechanical analysis of the three-dimensional model of the three-unit dental bridge in the area of the first and second premolars and the first molar of the lower jaw was performed in Ansys Workbench software. A dental bridge made of type 2 gold alloy and Lithium disilicate ceramic was exposed to fluid at 60 and 4 °C for 5 seconds on the chewing and lingual surface of the tooth. In addition, static load and shock load were applied in the middle of the dental bridge. The first static load was applied vertically and the second static load was applied obliquely at an angle of 45 degrees to the chewing surface and towards the buccal surface. The simulation of the impact force was carried out through the impactor with various kinetic energies perpendicular to the surface of the rodent. The maximum thermal stress created at 4°C was higher than at 60°C and was dependent on the thermal expansion coefficient, Young's modulus, and temperature field. In addition, the maximum thermal stress in the gold dental bridge was about 30% higher than the ceramic bridge. It was also found that in cases where only vertical forces are considered, the stress is predicted to be about 40% less than the oblique force. The stress severity under the rigid impactor with kinetic energy of 19.4, 8.6, and 2.2 mJ was calculated for the impactor as 3, 2.2, and 1.35 times the static stress, respectively, and the reaction force in the roots is proportional to the amount of impactor kinetic energy. Based on the results of this research, the stresses created in the dental bridge in cold thermal stimulation and impact loading are more critical than other loading modes. On average, ceramic dental bridges create less tension in dental bridges and tooth tissue.
