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Updated: Jun 18, 2026
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Shrinkage of Dental Composite in Simulated Cavity Measured with Digital Image Correlation
Published on: July 21, 2014
Polymerization composite shrinkage evaluation with 3D deformation analysis from microCT images
Yu-Chih Chiang1, Peter Rösch, Alp Dabanoglu
1Department of Restorative Dentistry and Periodontology, Dental School of the Ludwig-Maximilians-University, Goethestr. 70, D-80336 Munich, Germany.
Summary
This study developed a novel method to visualize polymerization shrinkage in dental composites. The technique revealed that bonding significantly impacts shrinkage direction and magnitude, offering insights for improved restorative techniques.
Area of Science:
- Materials Science
- Biomaterials Engineering
- Dental Restorations
Background:
- Polymerization shrinkage is a critical challenge in dental restorations, potentially leading to marginal gaps and secondary caries.
- Accurate measurement and visualization of shrinkage are essential for understanding its effects and developing improved materials and techniques.
Purpose of the Study:
- To develop and validate a novel experimental method for determining and visualizing the three-dimensional direction and magnitude of polymerization shrinkage in dental composites.
- To investigate the influence of bonding on the patterns of polymerization shrinkage.
Main Methods:
- Dental composite was modified with traceable glass beads.
- Cylindrical cavities were restored with the composite, both with and without dentin adhesive.
- High-resolution micro-computed tomography (microCT) was used to capture 3D images before and after curing.
- Image segmentation and local rigid registration were applied to glass beads to calculate displacement vectors.
Main Results:
- Unbonded restorations showed inward shrinkage towards the center of mass.
- Bonded restorations exhibited varied contraction patterns, directed towards the cavity side or restoration surface.
- The magnitude of shrinkage was significantly greater in bonded restorations (46.8 µm) compared to unbonded ones (31.3 µm).
Conclusions:
- The developed microCT-based method effectively visualizes polymerization shrinkage in 3D.
- Bonding quality and cavity geometry critically influence the direction of polymerization contraction.
- This method provides a valuable tool for validating computational models of polymerization shrinkage.
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