Related Experiment Video
Updated: Aug 2, 2026
08:45
Shrinkage of Dental Composite in Simulated Cavity Measured with Digital Image Correlation
Published on: July 21, 2014
Polymerization shrinkage of densely-filled resin composites
1Department of Restorative Dentistry, School of Dentistry, University of Washington, Seattle 98195-7456, USA.
Operative Dentistry
|September 12, 2001
Summary
Packable composites, a new dental restorative material, show varied polymerization shrinkage. Some densely filled composites (DFC) exhibited less shrinkage than conventional hybrids, with filler volume playing a moderate role.
Area of Science:
- Dental Materials Science
- Polymer Chemistry
- Restorative Dentistry
Background:
- Packable composites are a novel class of dental restorative materials.
- These are highly-filled or densely-filled hybrid resin composites.
- A key claim is reduced polymerization shrinkage compared to conventional composites.
Purpose of the Study:
- To compare linear polymerization shrinkage between densely filled composites (DFC) and conventional hybrid resin composites.
- To evaluate shrinkage in DFC resins (Alert, Ariston, P60, Prodigy, Solitaire, Surefil) and hybrid resins (TPH-Spectrum, Z100).
- To investigate the relationship between filler characteristics and polymerization shrinkage.
Main Methods:
- In vitro investigation using a visible halogen light curing source.
- Linear dimensional change measured using a calibrated light microscope.
- Statistical analysis included one-way ANOVA with Student-Newman-Keuls post-hoc test and Pearson's Correlation.
Main Results:
- Alert and P-60 demonstrated significantly less shrinkage than Solitaire, Ariston, Prodigy, Z-100, and TPH-S.
- Shrinkage varied among DFC resins; some showed significantly less shrinkage, while others had comparable shrinkage to conventional hybrids.
- A moderate association was found between filler volume and polymerization shrinkage.
Conclusions:
- Some densely filled composites offer reduced polymerization shrinkage compared to conventional hybrid resins.
- Filler volume, filler size, and resin chemistry are critical factors influencing polymerization shrinkage in dental composites.
- The performance of packable composites regarding shrinkage is material-dependent.
Related Concept Videos
01:14Polymer Classification: Architecture
Polymers are classified as linear or branched on the basis of their chain architecture. The polymer chains in linear polymers have a long chain-like structure with minimal to no branching at all. Even if a polymer features large substituent groups on the monomer, which appear as branches to the skeleton, it is not considered a branched polymer. A branched polymer contains secondary polymer chains that arise from the main polymer chain. The branching occurs when the polymer growth shifts from...
01:21Polymer Classification: Crystallinity
Unlike ionic or small covalent molecules, polymers do not form crystalline solids due to the diffusion limitations of their long-chain structures. However, polymers contain microscopic crystalline domains separated by amorphous domains.
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
Crystalline domains are the regions where polymer chains are aligned in an orderly manner and held together in proximity by intermolecular forces. For example, chains in the crystalline domains of polyethylene and nylon are bound together by van der Waals...
01:26Polymer Classification: Stereospecificity
Polymerization generates chiral centers along the entire backbone of a polymer chain. Accordingly, the stereochemistry of the substituent group has a significant effect on polymer properties. Polymers formed from monosubstituted alkene monomers feature chiral carbons at every alternate position in the polymer backbone. Relative to the predominant orientation of substituents at the adjacent chiral carbons, the polymer can exist in three different configurations: isotactic, syndiotactic, and...
01:08Molecular Weight of Step-Growth Polymers
Step growth polymerization involves bi or multifunctional monomers. Bifunctional monomers react to form linear step growth polymers, whereas multifunctional monomers react to form non-linear or branched polymers.
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
As the step-growth polymerization involves step-wise condensation of monomers, the molecular weight also builds up eventually. Consequently, high molecular weight polymers are obtained at the late stages of the polymerization, where 99% of monomers have been consumed.
The extent of the...
01:27Shrinkage in Concrete
Shrinkage in concrete is primarily due to water loss from evaporation, hydration of cement, or carbonation, leading to a reduction in volume. The volumetric contraction results in volumetric strain in concrete. However, in practice, shrinkage is measured as linear strain, which is one-third of the volumetric strain.
When concrete is still in its plastic state, it can undergo a decrease in volume by about 1% of its absolute volume. This decrease is known as plastic shrinkage. It arises either...
When concrete is still in its plastic state, it can undergo a decrease in volume by about 1% of its absolute volume. This decrease is known as plastic shrinkage. It arises either...
01:21Drying Shrinkage
When hardened concrete is exposed to air with a relative humidity of less than 100 percent, it begins to lose the free water within its capillaries. As this water evaporates, the water initially adsorbed onto the calcium silicate hydrates migrates towards these now empty spaces and eventually evaporates as well. Over time, as more water leaves, the volume of the concrete decreases, a phenomenon known as drying shrinkage.
A portion of this drying shrinkage can be reversed; if the concrete is...
A portion of this drying shrinkage can be reversed; if the concrete is...