Eric Johnson, DMD

You can try using take home trays and do a touch up for an hour each day until the stain is removed again. Don't worry, you should still be able to get white teeth again, it will just take a few days.

You can make the switch to 14% day white, but just be sure to take a few days off if you do develop any sensitivity. The stronger solutions are more likely to cause sensitivity.

Zoom works very well on yellowish stains, so you should see a big improvement even in just 1 session. In my opinion looking into Invisalign or ClearCorrect along with whitening may give you better results than bonding.

Yes zoom should work for your yellowing teeth. Just be aware that they may become even more transparent looking when the yellow stains are removed.

It depends a lot on your diet, but it is normal to touch up with the take home trays. Most dentists sell take home solution that works better and causes less sensitivity than the over the counter options.