Computational model of the contraction caused by the polymerization of bulk fill dental resin and experimental validation
Claudio Antunes Junior1; Emílio Graciliano Ferreira Mercuri1; Ana Paula Gebert de Oliveira Franco2; Leandro Zen Karam3; Manoella Costa4
1 Universidade Federal do Paraná; 2 Universidade Tecnológica Federal do Paraná; 3 Pontifícia Universidade Católica do Paraná; 4 Universidade Estadual de Ponta Grossa
doi:10.20906/CPS/CILAMCE2017-0488
Resumo
The objective of this work is the development of a computational experiment and the comparison with a laboratorial experiment of the contraction caused by the polymerization of bulk fill dental resins. Volumetric changes of light-activated composites, especially contraction stresses, can cause adhesive interface failure. This undesirable defect may lead to micro infiltration, and, consequently, the development of marginal caries, postoperative sensitivity and pulp damage. The laboratory experiment was performed in third human molars, in which a 4x4x4 mm cavity was created and two through holes perpendicular to each other at 2 mm and 3 mm from the bottom of the cavity. In these holes was inserted optical fiber recorded with two Bragg nets that function as two sensors with different wavelengths that measure temperature and deformation. The two sensors were installed in directions perpendicular to each other and one of them was inserted in a hypodermic needle to isolate the effect of the deformation. After tooth preparation, the cavity was filled using Filtek Fill Flow resin (3M / ESPE) which was photoactivated for 10 seconds with the LED device (Vallo Cordless/Ultradent). The data was analyzed statistically and converted to temperature and deformation. The sensor at 2 mm from the bottom of the cavity measured the deformation and temperature while the sensor 3 mm from the bottom of the cavity that was inside the needle measured only the temperature. For the computational experiment, a tooth was chosen that presented the best results according to the average of the samples of the laboratory experiment. After the choice, a CT scan was performed with the PreXion3D Elite CBCT Scanner equipment and afterwards the image was reconstructed three-dimensional with the use of InVesalius 3 software. From this the three-dimensional model of the tooth was inserted into Ansys software along with the equations governing the Generalized Kelvin-Voigt model for solving the equilibrium equations of the deformable solid through the Fini
Palavras-chave: dental composite resins; FEM; polymerization; contraction; temperature