I know exactly what you mean, but at least you KNOW your vet is competent.
Another idea is a portable water pic. I can't remember which GTer uses it with her senior girl, but they said they had great results. You just have to do it outside because it's gross.
Lucy just had her dental, and I'm going to go pick one up and try it. Her gums have pockets on the outside that always fill up with crud no matter what, so I figure rinsing couldn't hurt.
Diesel also got the vote for 6 month dentals, but that is a no way jose thing as he does very poorly with anesthesia too. Our new vet and I talked about it in great detail, and he also said it was most likely the injectable that was causing the issue, so he would be conservative with that one.
I'm still not ready though, after Sally's spay, Lucy's dental and a round of shots for every one, I'd rather water pic and denta treat for a little while yet.