Calculating internal stress during curing of dental composites

abrasion resistance, ease of handling and mechanical and chemical

stability influence each other and have to be optimized in a complex

process. Despite intensive research, the polymerization shrinkage during

the curing process leads to internal stresses. The magnitude of the

stresses is influenced by the polymerization shrinkage, increasing

stiffness, decreasing viscosity, and the geometrical shape of the

cavity. During material development one has to ensure marginal integrity

of a restoration by model experiments.

We developed a testing approach for dental composites which includes a

coupled experimental and numerical method. Using this approach, we

estimated the necessary parameter that can be used for a simulation of

the build-up of internal stresses in arbitrary filling geometries.