Braces and cavities??

Hi! I'm going to get my braces off soon, and I really hope that I won't have any cavities, which I think I might have a few, but my family members don't think I will. Anyways, I just have a few questions about cavities under braces.
1. Can you always tell if you have a cavity under a bracket?
2. What color would the cavity be?
3. Do a lot of people have cavities under braces?
4. How much does it cost to fill a cavity that was once under a bracket?

Thank you very much.

Yes and No. It takes awhile for a cavity to start. Abrown spot or dark area could be a cavity but also could be stain.
Some people experience cavities while in braces because oral hygiene is harder to maintain. I reccomend brushing and using special floss threaders under brackets. Also a good flouride toothpaste. Most people still are under the care of a general dentist while still in braces, which means 6month checkups and flouride treatments. Your orthodontist should also inform you of any irregularities in visits(since he or she may see you on a more regular visit.)
Regular hygiene maitance(cleanings/xrays/flouride) 2x yearly are less expensive than letting them go and having lots of restorative work done
Hygiene 2xz year-88-120 a visit
fillings(composite or white fills,depending on how many surfaces it covers the tooth (how big) can be 100 and up(thats just one tooth!)
Insurance helps also.
Hope this helps