I think you could drive your self batty trying to figure it out. I'd let the vet check it out since you will be there.
If the electrical cord had copper or something in it, I'd guess maybe that could have happened. Or maybe it could have something to do with being on antibiotics and chewing raw bones. I'd be interested in what the vet says.
Hondo used to chew rocks as a youngster (big ones, not the kind you can swallow). His teeth don't show any signs of scrapes or scratches. But he was only on antibiotics once.
Hondo Von Dopplet L Bauernhof "Hondo"- GSD
Lilie's Tug McGraw "Tug" - Golden Retriever
Maggie - Mini Dachshund (Rescue)
Lonestar Pivo - Texas Blue Lacy
Ashe - Barn Cat
Katie / APHA