Computer Aided Design Modelling and Finite Element Analysis of Premolar Proximal Cavities Restored with Resin Composites

Abstract

This study evaluated the stress distribution in five different class II cavities of premolar models restored with conventional or bulk-fill flowable composite by means of finite element analysis (FEA) under shrinkage and occlusal loading. An upper validated premolar model was imported in the software, and five class II cavities with different occlusal extensions and dimensions were prepared: horizontal cavity on the mesial surface (horizontal slot), mesio-occlusal cavity, mesial cavity (vertical slot), tunnel type cavity and direct access cavity. The models were restored with conventional or bulk-fill flowable resin composite. The tested materials were considered as homogeneous, linear, and isotropic. The Maximum Principal Stress criteria was chosen to evaluate the tensile stress results. The lowest shrinkage stress value was observed in the direct access cavity restored with bulk-fill flowable resin composite (36.12 MPa). The same cavity, restored with conventional composite showed a score of 36.14 MPa. The horizontal slot cavity with bulk-fill flowable showed a score of 46.71 MPa. The mesio-occlusal cavity with bulk-fill flowable had a score of 53.10 MPa, while with conventional composite this was 55.35 MPa. Higher shrinkage stress was found in the vertical slot cavity with conventional resin 56.14 MPa, followed by the same cavity with bulk-fill flowable 56.08 MPa. Results indicated that the use of bulk-fill flowable composite resin more significantly decreased the polymerization shrinkage stress magnitude. The larger the cavity and the volume of material necessary to restore the tooth, the greater the residual stress on enamel and dentin tissue.

Finite Element Analysis of Restored Principal Abutment in Free-End Saddle Partial Denture

“…Furthermore, the results were not calculated considering data deviation or systematic error which can be present in biological tissues and complex systems. 13 Despite limitations, the present study assists clinicians in selecting the appropriate composite resin when an improved mechanical response is needed. 6 …”

Stress Concentration of Endodontically Treated Molars Restored with Transfixed Glass Fiber Post: 3D-Finite Element Analysis

“…Initially, the endodontically treated teeth would be subject to different temperature cycles and pH variation in the oral cavity. In addition, the simulated materials would present some defects that are not simulated in isotropic structures [ 41 ]. There are, possible influences of oblique loading, sliding contacts and operator errors that are simplified [ 42 ].…”

Polymerization Shrinkage, Hygroscopic Expansion, Elastic Modulus and Degree of Conversion of Different Composites for Dental Application

“…Biomaterials that possess adequate compressive and tensile strength and relatively low elastic modulus could act as a cushion layer to the shrinkage stress transmitted to the tooth tissues [21]. However, in adhesive restorations, the mechanical behavior under compressive loading and shrinkage stress can be associated with several factors other than the material, including the enamel and dentine volumes lost [4]. In this study, the highest Elastic modulus mean value was observed for Grandio (22.15 ± 2.68 GPa) and the lowest for 4 Seasons (10.06 ± 1.37 GPa), as observed in Table 5.…”

“…The main challenge of developing these materials is to provide an effective bond strength to the hard tissues, such as enamel and dentin, as well as lower or no polymerization shrinkage [1,2]. In addition, the mechanical and chemical properties of these materials have been improved along the years [1][2][3][4], positively affecting their clinical performance. The aesthetic restorative technique has also been improved, which increases the longevity of the resin-based restorations, especially for posterior teeth [4][5][6].…”

“…In addition, the mechanical and chemical properties of these materials have been improved along the years [1][2][3][4], positively affecting their clinical performance. The aesthetic restorative technique has also been improved, which increases the longevity of the resin-based restorations, especially for posterior teeth [4][5][6]. The maintenance of the marginal sealing and good quality of restoration filling techniques are the main focus during the treatment with conservative (non-replacement) dental restorations [7,8].…”