If you brush efficiently EVERY DAY, you remove the plaque, but if you still have issues, steroid may be the magic bullet. My vet suggested trying them before removing her teeth after a year of battling (cleaning every 3 mos and nightly brushing) and still ended up removing teeth. For us, low dose steroid was in fact the magic bullet. We have managed to lose no teeth and keep her mouth good for nearly 8 yrs.
CUPS is an autoimmune problem, so my vet, UGA and a specialist I called ALL agreed, she that low dose steroids might help as she may not need the steroids just for her mouth but to help keep systemic autoimmune at bay. Further, they warned even with removal, could STILL have inflammation, so going steroids first was the best choice. I am very glad your dog has done so well, but did your vet even offer steroid trial?
In cases in which discomfort is severe and the owners are unable or unwilling to brush the teeth, extraction of all teeth associated with ulcers may be necessary to remove the contact surfaces on which plaque accumulates. Although this may help control the lesions, it is not curative, because plaque forms on mucosal surfaces in the mouth, including the tongue. In some cases with complete extractions, dogs continue to develop lesions due to a hyperimmune response to the plaque.<<
I'm a bit excited they have had success with cats with gum inflammation : http://www.vetmed.ucdavis.edu/whatsnew/article.cfm?id=2789