Fatigue of restorative materials

Area of Science:

• Biomaterials science
• Dental materials engineering
• Mechanical engineering

Background:

• Fatigue failure in dental prostheses presents as wear, margin fracture, coating delamination, and bulk fracture.
• Material ductility influences fatigue failure mechanisms; brittle materials fail catastrophically, while ductile materials use plasticity to mitigate stress.
• The high cost of replacing failed restorations drives the need for laboratory evaluation of material fatigue resistance.

Purpose of the Study:

• To review the mechanisms of fatigue failure in dental materials.
• To discuss the methodologies and variables in laboratory fatigue testing.
• To highlight the application of fatigue data in predicting the longevity of dental restorations.

Main Methods:

• Review of fatigue failure mechanisms in dental materials based on material ductility.
• Analysis of fatigue testing variables including loading mode and test environment (e.g., water immersion).
• Examination of outcome variables, typically fracture strength, and their statistical analysis using Weibull distribution.

Main Results:

• Fatigue data analysis allows for predictive inferences regarding the survival of dental restorative materials under specific loading conditions.
• Wear and survival of porcelain restorations have been modeled using fracture mechanics and probabilistic approaches.
• Limited application of in vitro fatigue data for clinical failure prediction exists.

Conclusions:

• Fatigue testing is crucial for evaluating dental restorative materials.
• Further development of clinical failure databases and valid test methods for composite materials is needed.
• Predictive models based on fatigue data can inform the design and selection of durable dental prostheses.