Yes. You won't be dependent like with a drug, but when it get the time to relax for you, it will be harder for you to meditate without such waves. You brain will get use to it and will want to wait for the brainwaves before starting to generate waves itself.

However, I do not think for using them every now and then will be an issue at all. Do both meditation with and without waves and you will be fine.

Alpha waves is for light sleep (lucid dreaming, astral projection, etc)

Delta waves is for people in a coma and while in deep sleep (non rem dreams)