Not really. The dangerous aspect of a knife is when it moves unexpectedly. The sharper it is, the harder it is to create a scenario where it jumps on something particularly dense, like when a saw hits a knot in a tree.

If you’re pushing down with hard force, it basically doesn’t matter if the knife is sharp anymore, it’ll just chop your finger off. However, with an extremely fine cut, it will be much easier to reattach, as the edges will match up well. With a dull knife, you’re not slicing, you’re more tearing your way through something.