Which statement about light-cured composites is true?

Light-cured composites are materials widely used in dentistry due to their aesthetic qualities and usability. One key characteristic that influences the curing of these composites is opacity. When a composite is more opaque, it can hinder the penetration of light needed for effective polymerization, leading to longer curing times. Therefore, it's accurate to state that opacity affects curing times.

Particle size, on the other hand, primarily influences other properties of the composite, such as the material's strength, wear resistance, and polishability rather than directly affecting the curing times. The composition and arrangement of particles play a more significant role in the physical properties of the cured composite rather than in how quickly or effectively it cures under light.

Hence, the assertion that opacity affects curing times while particle size does not is true, as it accurately identifies the impact of opacity on the light curing process without attributing that same level of influence to particle size.