toilet flange question

I installed a new floor that's 1/4 inch lower than the old one. The toilet flange was a nice, tight fit with the old floor, but now it sticks up about 1/4 inch. I am wondering whether I can reinforce the flange (with some wood putty, washers or something along those lines), then install the toilet. I don't know whether the toilet will sit flat, but if it does, are there other problems that might come up? Is it really necessary in this circumstance to have a plumber lower the flange? If so, how much is it likely to cost (this bathroom was added in the mid 1990s, so I'm pretty sure everything is pvc.)?

Thanks . . .

Tom

IF the toilet will fit over the flange without rocking, you still need to support the flange and have it attached to the floor firmly since it is what holds the toilet in place. You need something solid under the flange, maybe some plywood rings, split and glued to the subfloor. Keep in mind that the wax ring will be compressed to almost nothing in this case. I'm not a pro...take it for what it's worth...

Sometimes, there is enough slack in the drain line that you can push it down enough to reattach the flange to the lowered floor. Note that you still need the 1/4" per foot slope of the drain, and this may cause it to be too shallow and give you other problems. If it is cast iron, then this won't work.

Many plumbers set the flange over the floor anyway. I don't see a problem here as long as the flange is secure to the floor.
When the toilet is bolted down, you don't want it moving.