Zirconia-based dental crown to support a removable partial denture: a three-dimensional finite element analysis using...

Area of Science:

• Biomaterials Science
• Dental Materials
• Mechanical Engineering

Background:

• Veneer fracture is a primary complication in zirconia-based dental restorations.
• Understanding the mechanical behavior of these restorations under load is crucial for improving longevity.

Purpose of the Study:

• To evaluate the mechanical performance of zirconia-based crowns supporting removable partial dentures (RPDs).
• To investigate the impact of veneer/coping bond quality on stress distribution within the restoration.

Main Methods:

• Finite element models (FEM) were created using microtomography (μCT) data of a lower canine tooth.
• Models simulated gold (MAu) and zirconia (MZi) cores with complete and incomplete veneer bonding (MZi-NL).
• Stress analysis was performed using Ansys Workbench 10.0 under simulated functional loading.

Main Results:

• Complete bonding showed similar maximum principal stress (σmax) for gold (0.42 MPa) and zirconia (0.40 MPa) cores.
• Incomplete bonding in zirconia (MZi-NL) drastically increased veneer σmax by up to 800% (3.23 MPa).
• Von Mises equivalent stress (σvM) also increased by up to 270% in the incomplete bonded zirconia condition.

Conclusions:

• Incomplete bonding at the veneer/zirconia interface significantly elevates stress levels.
• Ensuring complete adhesion is vital to prevent catastrophic veneer fractures in zirconia dental restorations.
• This highlights the critical role of interface integrity in the mechanical success of RPDs.