when they said they wanted to drill, the thing they want to drill out was the previous work. and, when they said they wanted to fill, what they meant is they want to fill the holes they created by drilling out the previous work and replacing it.
that seems to both make sense and align well with what i can see in my mouth. so, i'm accepting his statements because they make sense and seem right, where what the others said seemed wrong and didn't align well with what i could observe.
it means that what i'm concerned about is not removing plaque or cavities, but removing stains and rebuilding the gums.