Plan to wear your retainer full time for 6 months if you want very perfect teeth. If you need to take the retainer out if you are giving a presentation or talking a lot, that is fine, but you should ALWAYS wear it at night, especially for the first 6 months. After that, you should still wear it at night for many years. My sister has had her braces off for 4 years and her teeth still shift when she doesn't wear her retainer at night for a couple of days. The orthodontist will tell you to wear it full time for 6 months, except when you eat. Then after that they will check your progress and give you further direction; usually only to wear it at night. Good luck and don't get discouraged if you have trouble talking! If you stick with it for the first 2 weeks, you'll be talking perfectly before you know it.