Polymerization shrinkage, reduction

While these approaches did provide for reductions in polymerization shrinkage and improvements in adhesion, the oxaspiro monomers were more sluggish in free... 

Nanofillers are usually invisible and offer many advantages to dental composites, such as optical property improvement [92], increase of the overall filler content to as high as 90-95 % of the composite by weight, and reduction of polymerization shrinkage due to a lower amount of the monomeric phase [16]. 

Turagam, N., Prasad Mudrakola, D. Effect of micro-additions of carbon nanotubes to polymethylmethacrylate on reduction in polymerization shrinkage. J. Prosthodontics. 22, 105-111(2013)... 

Extenders may also provide one or several secondary functions in addition to cost reduction. Depending on the type and concentration of the extender, it could reduce shrinkage that occurs on polymerization or during aging, lower the coefficient of thermal expansion of the adhesive formulation, provide a higher viscosity to avoid adhesive starvation in the joint, or perform a number of other property improvements. 

The brittleness of specimens under normal compression depends also on the ambient medium and on exposme. Specimens fixed with Sprut-5M under water and in oil are less brittle than specimens fixed in air. Reduction of brittleness mder water and in oil is somewhat characteristic of the specimens glued with VAK also. This may be explained by the plasticizing influence of the hquid medium on the adhesive joint borders, leading to partial elimination of the stress concentration factor [360] that occurs with adhesive shrinkage in the process of polymerization. 

All monomers, but a few exceptions exhibit shrinkage upon polymerization since Van der Waals bonds are converted into much shorter covalent bonds. The accompanying reduction of the entropy also favors a closer packing. When a surface with a specified curvature has to be made by replication from a mold, due allowance has to be made for shrinkage of the replication coating. This means that the shape of... 

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