Biomechanical behavior and stress distribution for conventional and 3D printing temporary resins

Abstract

Objetive: analyze the biomechanical behavior and stress distribution of a temporary resin for 3D printing Methodology: the samples will be drawn, using modeling software (Rhinoceros6.0 SR8, McNell, North America, USA), 25 mm x 10 mm x 3 mm, following the instructions of the ISO 4049 standard. The bars will be saved in an STL file (standard tessellation language) and exported to the specific software of the 3D printer (W3D Print, Wilcox) to be printed with a conventional resin (ResilabTemp,Wilcox). Bars will be manufactured in temporary self-curing acrylic resin containing the same dimensions as the printed samples and will be made by molding a bar printed with condensation silicone. The study will be divided into two parts. The first consists of defining the ideal conditions and parameters for printing and characterization of resins. The second part will be doing the analysis of the biomechanical behavior and stress distribution of the specimens. In the first part, the samples will be analyzed by FT-IR (model LR 64912C, Perkin Elmer) to analyze the degree of conversion and there will be the determination of the elastic modulus of the materials, by a pulse receiver (MOD 5900 PR, Olympus, USA) connected to an oscilloscope (TDS 1002, Tektronix, USA), by the pulse-echo method. For the elastic modulus calculations, it will be necessary to calculate the density of the samples, which will be measured by the Archimedes method on a precision scale. In the second part, the flexural strength test will be performed, using the recommendations of the ISO4049 standard. A universal testing machine will be used (Emic DL-1000, Emic, São José dos Pinhais, PR, Brazil), and the load will be applied until fracture. In addition, the stress distribution analysis will be performed by the Finite Element Analysis (FEA), and the three-dimensional (3D) models will be obtained through the design of full crowns according to the anatomy of the maxillary second molar by the modeling software and will be exported to the Ansys software (version 17.0, Ansys, Canonsburg, USA) for the pre-processing phase of finite element analysis, being transformed into three-dimensional solid models. The chosen analysis criterion will be the evaluation of the maximum principal stress (MPS). Descriptive statistical analyzes will be performed to define the inferential statistical tests. The results will be discussed against the relevant literature.(AU)