Finite element analysis (FEA) presents a wide range of application in Dentistry. FEA models can precisely calculate the material stress in conditions of geometry and boundaries that can properly represent the clinical reality. However, as any research model, the FEA ones requires some simplifications to be feasible. The researcher challenge is to distinguish between the necessary simplifications and the misrepresentative ones. This textbook presents some information to help FEA users to improve their FEA result interpretation. In addition, it will help readers non familiar with this technique to understand the power of this tool, yet being able to critically analyzing the published FEA studies.