Hi Wandering Flame,
Well, I know that once your enamel is gone, it's gone. So it's important to look after your teeth to prevent enamel decay. Can you tell us about this metal utensil and what happened? I've had a chip on my tooth for quite a while and there's been no problems. A mark of 0.01 millimeters would barely be noticeable. Whether it would fill in through the process of remineralization or not, I don't know - teeth aren't my forte; computers are.
My recommendation would be, if you're seriously concerned, see your dentist. They'll be able to give you all the answers you seek. But, if you ask me, there's nothing to worry about.