plus you'll get some crevice corrosion exacerbating the stuff already mentioned!
I had ceramic and they were great (as great as braces can be). I had them on both top and bottom - it is nice as in photos the braces are much LESS noticeable than if you had metal. I never had any problems with them whatsoever. I did have a good friend who had both ceramic and metal (metal on the bottom) as the overbite (that was also being corrected) prevented the use of the ceramics on the bottom - be sure to check with your orthodontist as to whether you can have them on both bottom and top.
I have the ceramic kind and I really like them. In pictures you can't really see them as much so that's pretty nice. The only thing is the clear bands can turn yellow from eating things like soup, or drinking soft drinks, juice, tea, so you need to brush your teeth right after drinking those things. I noticed my bands were starting to turn yellow so I got an electric toothbrush, whitening tooth paste and whitening mouthwash and they went back to normal. So those are good things to have if you have ceramic braces.
