The influence the configuration of the preparation of inlays on the tension distribution on the fracture resistance of premolars restored with different materials

Abstract

The aim of this study is to evaluate the influence of width of the isthmus on the tension distribution and on the fracture resistance over human premolar teeth restored with esthetic indirect restoration. Methods: This study was divided in two parts, in the first, sixty-three hygid first upper premolar with similar geometry were collected and distributed into nine groups (n=7), G1-hygid teeth; G2- conservative inlay without restorative materials; G3-extensive inlays without restorative materials; G4-conservative inlay+indirect resin (Signum Ceramis-Heareus); G5-conservative inlay+e.max Press ceramic (Ivoclar Vivadenfj+sandblasting with silicate; Go-conservative inlay+e.max Press ceramic+10% hydrofluoric acid; G7-extensive inlay+indirect resin (Signum Ceramis) G8-extensive inlay+e.max Press ceramic+ sandblasting with silicate and G9-extensive inlay+e.max Press ceramic+10% hydrofluoric acid. To prepare the test, to standardize the prepare of inlays and simulate the periodontal ligament, it will be used a pantograph device (ParalAB) and an elastomeric polyether, Impregum-Soft MV (3M ESPE). This compound will be fixed in polyestirene and molded for the preparation of indirect restorations. The restorations will be luted using resin cement, dual Variolink II (Ivoclair Vivadent) and stored in distilled water at 37 °C for 24 hours. The fracture resistance test will be made 24 hours after on a Universal Test Machine (EMIC, DL 200MF) crosshead 1mm/min. In the second part of study, will be performed math test, finite element analysis (FEA). It will be obtained 3D models of anatomical structures. Then, will be done the modeling of work materials and mesh generation (FEA). The test results of fracture type and location of the concentration of stress will be possible inferences future where the cost sharing will be the hypothesis to be tested. (AU)