Three-dimensional finite element thermal analysis of dental tissues irradiated with Er,Cr:YSGG laser.
In the present study, a finite element model of a half-sectioned molar tooth was developed in order to understand the thermal behavior of dental hard tissues (both enamel and dentin) under laser irradiation. The model was validated by comparing it with an in vitro experiment where a sound molar tooth was irradiated by an Er,Cr:YSGG pulsed laser. The numerical tooth model was conceived to simulate the in vitro experiment, reproducing the dimensions and physical conditions of the typical molar sound tooth, considering laser energy absorption and calculating the heat transfer through the dental tissues in three dimensions. The numerical assay considered the same three laser energy densities at the same wavelength (2.79 microm) used in the experiment. A thermographic camera was used to perform the in vitro experiment, in which an Er,Cr:YSGG laser (2.79 microm) was used to irradiate tooth samples and the infrared images obtained were stored and analyzed. The temperature increments in both the finite element model and the in vitro experiment were compared. The distribution of temperature inside the tooth versus time plotted for two critical points showed a relatively good agreement between the results of the experiment and model. The three dimensional model allows one to understand how the heat propagates through the dentin and enamel and to relate the amount of energy applied, width of the laser pulses, and temperature inside the tooth.
Ana
Patricia Aparecida
PA
1Centro de Lasers e Aplicações, Instituto de Pesquisas Energéticas e Nucleares,Universidade de São Paulo São Paulo 05508-000, Brazil.
Velloso
Walter F
WF
Zezell
Denise Maria
DM
D003198:Computer Simulation; D003743:Dental Enamel / Q000528:radiation effects; D003804:Dentin / Q000528:radiation effects; D004548:Elasticity; D020342:Finite Element Analysis; D006801:Humans; D053844:Lasers, Solid-State; D008963:Molar / Q000528:radiation effects; D015203:Reproducibility of Results; D013696:Temperature