Dental Composite Shrinkage
Dental Composite Shrinkage - Related Videos
08:45
Shrinkage of Dental Composite in Simulated Cavity Measured with Digital Image Correlation
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Cited by 12 •
2014
In order to understand the spatial development of polymerization shrinkage stress in dental resin-composite restorations, Digital Image Correlation was used to provide full-field displacement/strain measurement of restored model glass cavities by correlating images of the restoration taken before and after polymerization.
01:27
Shrinkage in Concrete
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2024
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...
01:21
Drying Shrinkage
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2024
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...
01:24
Carbonation Shrinkage
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2024
Atmospheric CO2 penetrates the concrete's pores and, in the presence of moisture, forms carbonic acid, which then reacts with calcium hydroxide in the hydrated cement, forming calcium carbonate. This process reduces the concrete's volume and is termed carbonation shrinkage. The concrete's permeability is slightly reduced as calcium carbonate produced during the reaction fills its pores. Furthermore, its strength is slightly enhanced as the water released during the reaction facilitates the...
06:26
Experimental Implementation of a New Composite Fabrication Method: Exposing Bare Fibers on the Composite Surface by the Soft Layer Method
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Cited by 3 •
2017
A protocol to expose bare fibers on the composite surface by eliminating resin rich area is presented. The fibers are exposed during fabrication of the composites, not by the post surface treatment. The exposed carbon composites exhibit high electrical conductivity in the through-thickness direction and high mechanical property.
FAQs
As reactive monomer groups form a cross-linked polymer network, they move closer together and the material contracts. When the composite is bonded to relatively rigid enamel or dentin, that contraction cannot occur freely, so stress develops at the bonded interface. This helps explain why shrinkage-related effects can threaten marginal integrity and contribute to postoperative sensitivity or tooth damage.
Both activation pathways initiate polymerization, in which monomer molecules become connected within a cross-linked polymer network. The overview identifies light activation and chemical activation as routes that can generate contraction stress, but it does not establish that one pathway universally produces less shrinkage than the other. Their relevance is therefore linked to how the resulting stress affects the restoration and tooth interface.
The formulation of the composite, the way it is placed, and the curing protocol all influence how effectively shrinkage-related problems are managed. Material selection should account for the need to preserve marginal integrity, while incremental placement and optimized curing help support more reliable restorations. These choices matter because excessive contraction stress can promote gaps, sensitivity, or damage around the restoration.
Volumetric shrinkage describes the reduction in material volume as polymerization proceeds, whereas contraction stress describes the force generated when that reduction is constrained. The distinction is clinically important: a shrinking material becomes especially problematic when bonding to rigid tooth structure prevents free movement. Stress at that interface may then contribute to marginal gaps, postoperative sensitivity, enamel or dentin damage, and recurrent caries.
Incremental placement is one of the clinical strategies identified for managing the effects of composite contraction. Rather than relying only on material selection, the technique addresses how the restoration is built within the tooth. Used together with a suitable formulation and an optimized curing protocol, it can support more reliable marginal integrity and reduce the likelihood of shrinkage-associated complications.
Curing should be treated as a protocol that requires optimization rather than as a purely automatic final step. Because polymerization can generate contraction stress, the curing approach should be selected alongside the composite formulation and placement method. The goal is a more reliable restoration with better marginal integrity, while limiting conditions associated with gaps, postoperative sensitivity, or enamel and dentin damage.
Excessive contraction stress can compromise the junction between the restoration and the tooth, creating marginal gaps that weaken marginal integrity. It may also contribute to postoperative sensitivity and damage to enamel or dentin. Over time, these problems can support recurrent caries. Consequently, controlling shrinkage is relevant not only to material behavior but also to restoration durability and clinical outcomes.