Stress analysis of biomimetic restorations under thermomechanical loading using three-dimensional finite element analysis

Context: A finite element analysis (FEA) study utilized SolidWorks software to create four three-dimensional (3D) models of a mandibular first molar to evaluate stress patterns in the tooth restoration complex. Aims: The aim of the study was to evaluate the stress concentration on the tooth and restoration on thermomechanical loading using FEA. Subjects and Methods: A 3D model of the mandibular second premolar and first molar was constructed using anatomical dimensions from the cone-beam computed tomography. The model included enamel, dentin, pulp, and root structures, with supporting periodontal ligament and alveolar bone. A conventional mesio-occlusal class II cavity was prepared and restored with different composite resins as per the selected groups. This study evaluated four mandibular molar restoration models: (a) natural tooth; (b) tooth preparation restored completely with bulk-fill composite resin; (c) tooth preparation restored with low elastic modulus composite as dentin replacement, fiber-reinforced composite (FRC) as dentinoenamel junction (DEJ), and higher elastic modulus composite as enamel replacement; and (d) tooth preparation restored with dentin composite followed by lithium disilicate ceramic as enamel replacement. Results: Maximum principal stress values of dentin composite when used under indirect ceramic restoration were 5.675 MPa, and that of FRCs was 2.068 MPa. Maximum principal stress values on the dentin under indirect ceramic restoration and FRCs were 3.595 MPa and 2.427 MPa, respectively. Maximum principal stress values of dentin under bulk-fill composite resin were 3.090 MPa. Conclusions: The use of FRC layer as an intermediate layer to substitute the DEJ resulted in lesser stress concentration.