Transient thermal and stress analysis of maxillary second premolar tooth using an exact three-dimensional model.
OBJECTIVE
In this paper, the temperature and stress distributions in an exact 3D-model of a restored maxillary second premolar tooth are obtained with finite element approach.


OBJECTIVE
The carious teeth need to restore with appropriate restorative materials. There are too many restorative materials which can be used instead of tooth structures; since tooth structures are being replaced, the restorative materials should be similar to original structure as could as possible.


METHODS
In the present study, a Mesial Occlusal Distal (MOD) type of restoration is chosen and applied to a sound tooth model. Four cases of restoration are investigated: two cases in which base are used under restorative materials and two cases in which base is deleted. The restorative materials are amalgam and composite and glass-inomer is used as a base material. Modeling is done in the solid works ambient by means of an exact measuring of a typical human tooth dimensions. Tooth behavior under thermal load due to consuming hot liquids is analyzed by means of a three dimensional finite element method using ANSYS software. The highest values of tensile and compressive stresses are compared with tensile and compressive strength of the tooth and restorative materials and the value of shear stress on the tooth and restoration junctions is compared with the bond strength. Also, sound tooth under the same thermal load is analyzed and the results are compared with those obtained for restored models.


RESULTS
Temperature and stress distributions in the tooth are calculated for each case, with a special consideration in the vicinity of pulp and restoration region. Numerical results show that in two cases with amalgam, using the base material (Glass-ionomer) under the restorative material causes to decrease the maximum temperature in the restorative teeth. In the stress analysis, it is seen that the principal stress has its maximum values in composite restorations.


CONCLUSIONS
The maximum temperatures are found in the restoration case of amalgam without base. Besides, it is found that restoration has not any influence on the stress values at DEJ, such that for all cases, these values are close to sound tooth results.
Hashemipour
Maryam Alsadat
MA
Kerman Oral and Dental Diseases Research Center, Iran.
Mohammadpour
Ali
A
Nassab
Seiied Abdolreza Gandjalikhan
SA
D001641:Bicuspid / Q000502:physiology*; D001831:Body Temperature; D003188:Composite Resins; D019245:Compressive Strength; D003723:Dental Amalgam; D003782:Dental Pulp / Q000502:physiology; D003793:Dental Restoration, Permanent / Q000379:methods*; D003799:Dental Stress Analysis / Q000379:methods; D020342:Finite Element Analysis; D005899:Glass Ionomer Cements; D006801:Humans; D021621:Imaging, Three-Dimensional; D008437:Maxilla; D008954:Models, Biological; D033081:Shear Strength; D013718:Tensile Strength; D013814:Thermal Conductivity; D055471:Thermal Diffusion
D003188:Composite Resins; D005899:Glass Ionomer Cements; D003723:Dental Amalgam