I have had a Gillette Slim for the last 3 weeks. I like it a lot. However, I have found the challenge that arises from its versatility. There are 9 settings on it, and endless advice as to get the most from them.
Many suggest using a setting pattern of say, 7 (first pass), 5 (second pass), then 3 (third pass). I don't understand this. If there were areas of stubble that didn't get shaved properly after two passes of 7 & 5, quite how a pass on 3 is going to sort that out is beyond me.
Others say, "Put it on a setting that you like, and keep it on that setting for as many passes as you prefer."
I think the most logical approach is to do a pass or two at a lower setting, then for the final grande finale, increase it to 7+, on the basis that the final pass will be at the most aggressive level, thus ensuring the closest shave.
Finally, to answer your question - replating won't fix dents. But there are people who can fix dents. A razor restoration expert may be able to help you. Alternatively, a good quality jeweler or jewellery maker may be able to help.