Make sure that the teeth have at least a week to color stabilize after the whitening is done.. Lumineers sound easy and great but most dentists I know find them bulky and not very reliable cosmetically. Standard veneers are what I have personally and would not consider Lumineers even tho Im...
Any type of porcelain veneer is likely to chip, crack, or de-bond if habitual griding of the teeth occurs. A night guard should be worn every night and every time you take a nap. There are many kinds of night guards if you are having trouble adjusting the one you currently have.
If your new Lumineer feels bulkier than the the first one, it's probably because not all the cement from the first one was removed and so the second one is placed over a "thicker" tooth. If color and texture are different, that's because different technicians fabricate...