Can snails heal their broken shells?

If a snail is stood on and the shell is broken, do they have the ability to heal it somehow, or will they die? I was wondering if they would be able to produce something to coat the cracks, like when an oyster has some grit it produces the nacre to coat the grit to it doesn't irritate anymore, so can snails do something similar to fill in the cracks if their shells break?