Biomechanical Evaluation of CAD/CAM Inlay Restorations Through Experimental Flexural Strength Testing and Finite...

Area of Science:

• Biomaterials science
• Dental materials
• Mechanical engineering

Background:

• Investigating the biomechanical performance of dental restorations is crucial for clinical success.
• Conservative inlay restorations fabricated from various CAD/CAM materials require thorough evaluation.

Purpose of the Study:

• To assess the biomechanical behavior of different CAD/CAM inlay materials.
• To combine experimental flexural strength testing with finite element analysis (FEA) for comprehensive evaluation.

Main Methods:

• Five CAD/CAM materials were tested: feldspathic ceramic, leucite-reinforced ceramic, resin nano-ceramic, polymer-infiltrated ceramic network, and lithium disilicate ceramic.
• Material properties (Young's modulus, Poisson's ratio) were determined experimentally.
• 3D FEA was employed to analyze Von Mises (VM) stress distributions under simulated occlusal loading.

Main Results:

• Maximum VM stresses were inversely related to material elasticity.
• Lithium disilicate ceramic exhibited the highest maximum VM stress (45.571 MPa), while resin nano-ceramic showed the lowest (25.419 MPa).
• All tested VM values remained below the flexural strength (FS) limits of the respective materials.

Conclusions:

• All evaluated CAD/CAM materials demonstrated sufficient mechanical stability under physiological loads.
• Lithium disilicate provided a greater safety margin between stress levels and flexural strength.
• Lower-modulus materials may increase stress transfer to the supporting tooth structures.