It may or may not work, but it's generally not a good idea.
It also depends on how your teeth have changed in the last 5 years. You should visit an orthodontist to be properly evaluated to see whether you need retainers. Maybe he/she can tell you if it is ok to reuse that old one. Invisalign
is also an option for more minor corrections.
Would you like to video or text chat with me?
Answer assisted by Jin Packard, Medical Student