Related Experiment Videos
Photo-polymerization shrinkage-stress kinetics in resin-composites: methods development
D C Watts1, A S Marouf, A M Al-Hindi
1University of Manchester Dental School, Higher Cambridge Street, M15 6FH, Manchester, UK. david.watts@man.ac.uk
Summary
This study introduces a new device for measuring polymerization stress in dental composites. The system accurately quantifies shrinkage-strain kinetics, aiding in the development of better restorative materials.
Area of Science:
- Materials Science
- Biomaterials Engineering
- Dental Materials
Background:
- Shrinkage-strain kinetics in dental restoratives are increasingly studied.
- Concurrent stress-kinetic measurements are challenging but crucial.
- Existing methods lack the precision for light-cured materials.
Purpose of the Study:
- To design a novel methodology for concurrent stress-kinetic measurements.
- To develop a system suitable for light-cured dental restorative materials.
- To present illustrative stress-kinetic results for various restorative composites.
Main Methods:
- A calibrated cantilever beam-geometry load cell measured stress development.
- A novel specimen-holder design accommodated minimal system compliance.
- Disk-shaped specimens (10mm diameter, 0.8-1.2mm thickness) of four resin-composites were tested.
Main Results:
- The load cell exhibited a displacement of approximately 6 microm/MPa.
- Re-normalized maximum stress levels ranged from 5-8 MPa.
- Higher stress levels were observed with increased specimen thickness (1.2mm vs 0.8mm).
Conclusions:
- The developed device provides a practical, self-contained system for stress-kinetics.
- The methodology is suitable for both photo-polymerizing and self-cure materials.
- Accurate stress-kinetic measurements are achievable with the new apparatus.