What major difference exists between light-cured and chemical-cured composites during setting?

Light-cured composites and chemical-cured composites differ significantly in how they set, which directly impacts their properties during and after the curing process.

Light-cured composites polymerize when exposed to a specific wavelength of light, initiating a process that occurs rapidly. This rapid polymerization can lead to greater shrinkage because the material is hardening and setting more quickly, which may not allow for the same degree of expansion or contraction management as with chemical-cured composites. The chemical-cured composites, on the other hand, typically undergo a more gradual setting process, allowing them to shrink at a slower rate, which may be less pronounced and more controlled.

In contrast, aspects like margin sealing, wear resistance, and color stability are typically less dependent on the curing method and more on the specific formulation of the composite material itself. Therefore, the rapid shrinkage associated with light-cured composites is a key characteristic that distinguishes them from their chemically-cured counterparts, leading to differences in performance and clinical outcomes.