Hi so I have worn braces for two weeks now....

Hi so I have worn braces for two weeks now. Yesterday my dentist put my lower braces into place. Well putting them he realized that I have a deep overbite which can cause for me to bite into my braces and even break my brackets. That’s why he put the composite like substance onto my first pre-molars. He told me that I was going to have to keep those for a period of 1 to 4 months until my bite is corrected. After doing some research those are called composite veneers. But according to the web you never remove them at all. So is there a possibility that My orthodontist is lying to me? Or is it actually possible to keep the veneers for only such a small time period. Thank you very much and best regards