Clinically relevant approach to failure testing of all-ceramic restorations

Area of Science:

• Biomaterials Science
• Dental Materials Science
• Restorative Dentistry

Background:

• Traditional in vitro testing of single-unit restorations uses spherical indenters or flat platens.
• Clinical failure mechanisms and in vitro test behaviors are increasingly understood.
• This necessitates a re-evaluation of the clinical validity of current failure testing methods.

Purpose of the Study:

• Review traditional load-to-failure test characteristics.
• Contrast these with clinical failure modes of all-ceramic restorations.
• Identify and explain discrepancies between lab tests and clinical outcomes.

Main Methods:

• Literature review of intraoral conditions.
• Analysis of variables crucial for simulating clinical environments.
• Evaluation of recent laboratory testing advancements.

Main Results:

• Traditional fracture tests do not replicate clinical failure mechanisms observed in retrieved prostheses.
• Significant discrepancies exist between traditional lab testing and real-world restoration failures.
• Research has identified conditions to produce clinically relevant crack systems in all-ceramic restorations.

Conclusions:

• Current fracture tests for single-unit all-ceramic prostheses are inappropriate.
• Validated tests are essential to understand factors influencing prosthesis success (e.g., cement, bonding, occlusion).
• Advancements allow for the creation of clinically relevant crack systems in all-ceramic restorations.