Diametral compression test with composite disk for dentin bond strength measurement--finite element analysis

Area of Science:

• Biomaterials science
• Dental materials engineering
• Mechanical engineering

Background:

• Accurate measurement of bond strength between intracanal posts and dentin is crucial for successful dental restorations.
• A novel composite disk method under diametral compression was previously proposed for this measurement.
• Understanding stress distribution is essential for accurate interpretation of bond strength data.

Purpose of the Study:

• To analyze stress distribution within a composite disk used for measuring intracanal post-dentin bond strength.
• To evaluate the influence of geometrical and material parameters on post-dentin interfacial stress.
• To provide a basis for accurate calculation of bond strength using the composite disk method.

Main Methods:

• Finite element method (FEM) utilizing 3D models for stress analysis.
• Sensitivity analysis to assess the impact of parameter variations.
• Simulation of progressive interfacial debonding to model failure mechanisms.

Main Results:

• Material property mismatches induce stress concentrations at the post-dentin interface.
• Correction factors derived from numerical solutions are proposed for use with analytical models.
• Interfacial debonding is predicted to occur before dentin fracture, aligning with experimental observations.

Conclusions:

• The numerical analysis provides essential insights into stress distribution for the composite disk test.
• The presented numerical solutions support the wider adoption of this technique for bond strength assessment.
• This work enhances the accuracy and reliability of measuring intracanal post-dentin bond strength.