## 1 Introduction  
Modeling a system represents a fundamental step in understanding it while also providing a means to anticipate its future, yet-unknown behavior. With the advancement of information technology and computational systems, medical research has increasingly focused on developing sophisticated mathematical models capable of simulating the evolution of complex biomedical structures and processes. The biomechanics of the mandible, along with its mathematical modeling, are an emerging field of interest. This domain has captured the attention of scientists since the 1970s [1], marking the beginning of research in this direction. To obtain conclusive results, researchers today study this bony and articular component by considering physical elements, such as geometry, mechanical properties, and muscle activities, as well as pathological factors, such as bruxism, that contribute to the degradation of dental units [2]. The biomechanics of mastication and dental surfaces represent another field in which research through modeling and numerical simulation provides a means for observing and investigating biomechanical aspects characterized by a high degree of intra- and inter-individual variability [3]. These are biologically complex systems from a morpho-functional perspective, which, due to their small dimensions and limited accessibility, are not well-suited for direct investigations of patients [4, 5]. The loss of dental substance is a frequently encountered phenomenon with multiple causes, including oral parafunctional behaviors, particularly bruxism. Bruxism, characterized by clenching or grinding of the teeth, generates excessive forces that can lead to various hard tissue lesions, including occlusal surface wear, tooth fractures, or restoration failures [6]. Understanding how these parafunctional forces contribute to tissue damage requires a detailed biomechanical analysis of mechanical stress distribution. The three-dimensional modeling of mandibular and dental structures, combined with the finite element analysis (FEA) method, provides an effective approach for simulating and quantifying these mechanical loads. FEA enables the assessment of the impact of occlusal forces generated by bruxism on teeth, contributing to a better understanding of pathological mechanisms and optimizing the selection process of the materials used in dental restoration reconstructions. Three-dimensional modeling and finite element analysis (FEA) provide a powerful tool for investigating the biomechanical behavior of structures, allowing for the study of an unlimited number of variations [3]. By modifying different parameters, new models can be created--a process that would be impossible using traditional investigation methods. A major advantage of this approach is its ability to visualize internal stress distributions within structures, offering a detailed perspective on functional mechanisms [7]. The primary objective of this research was to develop and experimentally validate an innovative analog model correlated with a dedicated numerical model. Through these methodological tools, this study aimed to investigate and evaluate the forces exerted on medium- and large-sized dental restorations located at the level of the mandibular second premolar. The comparative analysis focused on two distinct types of restorative materials (amalgam and composite), along with the assessment of orthodontic biomechanics. This was achieved by simulating tooth displacement and the distribution of periodontal pressures through the application of orthodontic forces, either individually or in combination with an anti-rotational force coupler. Finite element analysis (FEA) involves a large number of equations and is based on several key principles, including object modeling, defining the material and contact parameters, discretizing the model and determining the element types (meshing), applying constraints and loads on the object, defining the contact types, solving the resulting mathematical equation systems, and displaying the simulation results [8].