Related Experiment Video
Updated: Aug 4, 2026
08:45
Shrinkage of Dental Composite in Simulated Cavity Measured with Digital Image Correlation
Published on: July 21, 2014
Stress relaxation modelling of polymethylmethacrylate bone cement
O R Eden1, A J C Lee, R M Hooper
1Department of Engineering, University of Exeter, UK.
Summary
This study models polymethylmethacrylate (PMMA) bone cement stress relaxation. Older PMMA bone cement stiffens and relaxes less, allowing long-term predictions from short-term tests.
Area of Science:
- Biomaterials Science
- Orthopedic Engineering
- Polymer Science
Background:
- Stress relaxation in polymethylmethacrylate (PMMA) bone cement is critical for load transfer in hip joint replacements.
- Understanding this behavior is essential for improving implant longevity and patient outcomes.
Purpose of the Study:
- To model the stress relaxation behavior of PMMA bone cement.
- To investigate the influence of aging on the mechanical properties of PMMA bone cement relevant to hip implants.
Main Methods:
- Stress relaxation tests were performed on PMMA samples of varying ages.
- A four-point bending configuration was utilized for the mechanical testing.
- The double exponential Maxwell model was employed to analyze the experimental data.
Main Results:
- PMMA bone cement samples exhibited increased stiffness with age.
- The degree of stress relaxation decreased as the PMMA samples aged.
- The Maxwell model accurately predicted the experimental stress relaxation results.
Conclusions:
- Aging significantly alters the stress relaxation properties of PMMA bone cement.
- The developed model enables accurate long-term stress predictions based on short-term mechanical tests.
- This research provides valuable insights for the design and performance assessment of hip joint prostheses.
