FEM analysis in endocron and onlay restorations produced with different materials

In this thesis, the biomechanical behaviors of endocrown and onlay restorations prepared using different materials were investigated using the finite element analysis (FEA) method. In restorative dental treatment, the management of material losses, especially in posterior teeth, is of great importance in terms of both the mechanical strength of the restoration and its compatibility with the dental tissue. Therefore, the aim of the study is to comparatively examine and evaluate the effect of the restorative materials used on the stress distribution. In the study, three-dimensional digital models were created using CBCT images of mandibular first molars extracted for periodontal reasons and different cavity designs (endocrown, MO, DO and MOD onlay) were modeled with SolidWorks software. Restorations were placed on each model using lithium disilicate glass ceramic, resin matrix infiltrated glass ceramic and bulk fill composite resin materials and stress analyses were performed on these models using Finite Element Analysis method. As a result of the findings, it has been shown that the elastic modulus and structural properties of the restorative material directly affect the distribution of stress on the tooth and restoration. Lithium disilicate glass ceramic restorations provide lower stress accumulation due to their high elastic modulus; while resin matrix materials have been observed to provide more homogeneous stress distribution. It has also been shown that the cavity type and preparation depth affect the stress concentration regions. In conclusion, it is emphasized that not only the material but also factors such as cavity design and the remaining structural integrity of the tooth should be taken into consideration in the success of the restoration, and this study reveals the importance of material selection based on biomechanical evaluation in the clinical decision process.