Influence of occlusal anatomy, resin cements properties and connectors type on the strength and stress distribution in metal free prostheses

Abstract

The purpose of this study will be analyses whether the different cusp inclinations, different design connectors, ceramic systems and the experimental resin cement properties will influence the resistance of free metal ceramic prostheses. Pillars of premolar and molar will be modeled end machined in G10 epoxy resin and to perform the anatomical design. The crown will be milling in 3 types of occlusal anatomy for further static structural analysis and the best anatomical angulations for the manufacture ceramics veneer will be milling for the study. After analyzing the results of the best anatomical design, 16 models will be designed in software CAD, Rhynoceros 4.0. The variables applied will be: connector, ceramic, width of cement and restoration technique. Three technique of veneering ceramic will be drawn: Rapid Layer, IPS emax CAD-on and conventional Feldspathic ceramic. The designed suggested by the manufacturing and some variations of the connector will be analyzed and which one show the best mechanical behavior will be tested in experimental set up in vitro. All groups will be cycled 1,200,000 - 4Hz, 200N. For analysis of the effect of the experimental resin cementsproperties, multiwalled carbon nanotube + nylon 6 (MWCNT/N6)nanofiberswill be made through the nanofiber electro-spinning that will be incorporated into cements manipulated. For the characterization of cement will be the following tests will be done: elastic modulus, volumetric polimerizationshrinkage, microhardness test (Knoop), contact angle, flexural strength, bi-axial flexural strength of ceramic-cement, shear testing of ceramic-cement interface and SEM analysis. After testing the data should be analyzed and the better test will be used for testing the hypothesis. (AU)