The effect of occlusal reduction and different CAD-CAM materials on stress distribution in endocrown restorations: A three-dimensional finite element analysis

Abstract

Aim: The aim of this study was to examine the effects of various preparation types and restorative materials on endocrown restorations applied to endodontically treated maxillary first molars and the stress distribution on the related tissues. Methodology: A three-dimensional (3D) image of a previously extracted intact tooth was obtained with CBCT. The resulting .dicom files were imported into Mimics. Enamel, dentine, and pulp were separated and extracted as an STL file. Four groups were determined and prepared in SolidWorks. The 3D images were imported into the relevant finite element analysis software (ABAQUS, 2020 Dassault Systems Simulation Corp., Johnston, RI, USA), and a load of 600 N was applied at the occlusal area of each model in the axial direction. Models were divided into three groups according to material type: Vita Suprinity (VS; VITA Zahnfabrik, Bad Sackingen, Germany), Cerasmart (CS; GC Corp., Tokyo, Japan), and Shofu Block HC (SB; Shofu, Kyoto, Japan). The type of cement used was RelyX ARC (3M ESPE, MN, USA). Results: Regardless of the results, stress on any tissue or restoration did not exceed the strength limits. In models with cusp preparation, the stress on the dental tissues was lower. Higher stress was generally observed in groups in which the lingual area was healthy. On the other hand, stress occurring in zirconia-reinforced glass ceramics (VS) is higher than in ceramic materials with a resin matrix (CS, SB). It has been determined that the stress transmitted to the supporting tissues is lower. Conclusion: Endocrown restorations can be used in the restoration of endodontically treated first molars. In addition, when endocrown restoration is applied to molars with only one healthy area and excessive loss of coronal structure, reducing the cusp is beneficial in terms of the distribution of stress on healthy tissues. How to cite this article: Tolu Gİ, Güntekin N, Mohammadi R, Demirel MG. The effect of occlusal reduction and different CAD-CAM materials on stress distribution in endocrown restorations: A three-dimensional finite element analysis. Int Dent Res 2022;12(Suppl.1):22-8. https://doi.org/10.5577/intdentres.461