Not if they really are dead, Lynne. If they're just looking 'tatty', then yes, cutting them back often gets a new spurt of growth. People normally start from scratch once winter pansies go over, though. You could grow some from seed for next year, or try violas - mine are still looking fine, as long as I keep dead-heading, but the pansies are in the compost bin.

I agree Spritz those little violas are a marvel and so prolific flowering. Such lovely colours too.