Effects of different cement-restorative material combinations in full-coverage onlay restorations: A FEA study

Area of Science:

• Biomaterials Science
• Dental Materials
• Finite Element Analysis (FEA)

Background:

• Indirect adhesive restorations (IAR) are crucial in modern dentistry for restoring tooth structure.
• Understanding the mechanical behavior of different cement-material combinations is essential for IAR longevity.
• Finite Element Analysis (FEA) provides a powerful tool for simulating stress distribution in complex dental structures.

Purpose of the Study:

• To evaluate stress distribution in indirect adhesive restorations using FEA.
• To compare the performance of various cement-material combinations under simulated chewing loads.
• To analyze the influence of restorative material type and cement properties on interfacial stresses.

Main Methods:

• A 3D Finite Element (FE) model of a lower first molar overlay restoration was created from micro-CT scans.
• Simulations involved applying axial chewing loads to linear elastic models of enamel, dentin, restorative materials, and cements.
• Analysis focused on shear stress and normal pressure at the tooth-cement and cement-restoration interfaces.

Main Results:

• Resin-matrix ceramic restorations exhibited the highest stresses, attributed to restoration flexion exacerbated by reduced occlusal thickness and lack of axial walls.
• Glass-matrix and polycrystalline ceramic restorations showed lower stress levels.
• Cement type (dual-cure resin vs. light-curable composite) had a minor impact on stress, with slight differences noted primarily under resin-matrix ceramics.

Conclusions:

• Resin-matrix ceramics are susceptible to higher interfacial stresses in overlay restorations, influenced by design factors.
• Cement selection appears less critical than restorative material choice, though low polymerization shrinkage cements are preferable for resin-matrix ceramics.
• FEA is valuable for predicting mechanical performance and guiding material selection in indirect adhesive restorations.