Honestly what Tracie is getting at is that the cause of her scales "rotting" in the first place might be much more serious than you know, and the main issue right now isn't whether the scales will grow back or not, it's why they ended up that way to begin with. It's not your fault, he contracted whatever it was or had the accident that caused it before you got him, but it very well may have been originally caused by a burn from his lights, a bite from another dragon he was housed with, a bite from a cricket left in his tank or a cut from some other accident that became infected, or unfortunately it could be a fungal infection...That's what we need to figure out, because if you treat it the wrong way you could actually make it worse.
Where did you get him? What did the "cut" or "rotted" area look like before the skin sloughed off? It is completely raw now and open down to his very first layers of skin, so that has to be horribly painful for him. What substrate do you have in the bottom of his tank? If it's any loose substrate at all, like sand, gravel, rocks, Coco husk, bark, mulch, walnut shells, etc. you need to remove it immediately and put down clean, dry papertowels that you can replace as they become soiled. But honestly I would take everything out of his tank ASAP anyway and completely disinfect his entire tank inside and out with very hot water and either bleach or F10 disinfectant, along with everything that is inside his tank, all decor, basking platforms, rocks, wood, bowls, everything. If it is a fungal or bacterial infection that he has you need to do this complete disinfecting to keep him from repetitively reinfecting himself. And loose substrates will get stuck to the wound, and they also harbor bacteria and fungi anyway, so if you have them get rid of them...I would take a photo of his entire body and his complete enclosure and lighting and post it for us to see...Does he have any other areas on his skin that look odd?