Dr. Jennifer Jo Garza, DDS

Yes you can get a cavity filled with braces on. Have your orthodontist take out the wire before your appointment with your dentist and then replace the wire after you get your filling. I typically call this a "sandwich" appointment. Where once you make the appointment with your dentist (your first step), call your orthodontist and make an appointment to remove the wire(s). The "sandwich" part is where your orthodontist is the "bread" (they see you before your cavity filling appointment), then the dentist is the "meat" of the sandwich (the middle of the sandwich), and then your orthodontist is the top bread layer of the sandwich. So, you will need 3 appointments in the following series: Orthodontist, Dentist, Orthodontist.

Check out YouTube. There are really good videos there. Waterpik's are also good, but don't replace flossing

It can be if you don't brush, floss or use fluoride appropriately

Floss a bunch, massage your gums with a wet toothbrush, no toothpaste, while watching TV or reading a book. You can also use salt water rinses and/or a cap full of Peroxide in a Dixie cup size amount of water

Yes, we need to see the roots of all of the teeth, see if there are any extra teeth, or stuck teeth or something else going on

You can. Check out some YouTube videos for technique, but basically, you want to brush at a 45 degree angle around each brace, brush in-between the braces with a "proxibrush". It kinda looks like a little Christmas Tree Pipe Cleaner with much softer bristles. The BEST kind of tooth brush though is one that is SONIC. Whether it's the Oral B Ortho Essentials kit or the Sonicare toothbrushes, the sonic waves really "jiggle" the plaque free all around the braces, and the teeth. You do not have to move the toothbrush around, like you do a manual/normal toothbrush. You simple put it on a tooth or two and let it jiggle there for a few seconds, then go to the next one or two teeth, and so on. The Water Pik is great for getting in-between the brackets. Although it doesn't replace flossing, it sure does a nice job. You can find coupons online for both I'm sure. I actually got coupons in the mail yesterday for my patients for the WaterPik.
Good luck in your braces journey!

It depends on the severity of the misalignment. It could be as little as a few months. Contact your local orthodontic specialist for a complimentary consultation for your individual needs.