The setting time for a condensation silicon impression material is best controlled by amount of accelerator added

The first light-activated systems were formulated for UV light to initiate free radicals. Today the UV light-cured composites have been replaced by visible blue-light-activated systems with greatly improved depth of cure, a controllable working time, and other advantages.

Because of these advantages, visibly light-activated composites are more widely used than are chemically acti wited materials.

For a diagnosis of systemic lupus erythematosus (SLE), at least four out of the eleven listed disorders must be present. These include malar rash, discoid rash, photosensitivity, oral ulcers, arthritis, serositis, renal disorder, neurologic disorder, hematologic disorder, immunologic disorder, and positive antinuclear antibodies.

The advantage of chisel and mallet over bur in removing bone is that no coolant is necessary.

Cytokeratin positivity in an undifferentiated malignant tumor suggests that the tumor is likely a carcinoma, as cytokeratins are markers for epithelial cells.