If you've already used the kidneys cleansing herbs than that is great, it's a very strong cleanse and it doesn't matter so much that you didn't follow the diet. You may want to just stick with water, cleansing drinks and a low-protein diet when next you wish to give the kidneys a break.
steam rooms are fun, just don't get too hot! and don't let your face hit the steam too direct-on, as the capillaries tend to burst easily from heat.
If you are using enemas/colonics to cleanse the colon after liver flushing, you should be able to flush while doing the dental work. It IS a long process and there are long breaks in between, right? So see how you feel. If you're up to it, then go for it! :) Just be sure to pamper your immune system!!! :)