Types of retainers…?
not wearing of retainers even years after orthodontic treatment would eventually leads to relapse (tooth tries to move back from its original crooked position) and since you have mention that you haven’t worn your reatiners for 2-3 years now, so im thinking that some of your teeth had already move from its perfect position. A possible orthodontic RE-treatment may be needed either with metal.clear braces or invisalign before you opt for retainers. after that, then a permanent bonded retainer would be a good option for you. Its placed at the back of your teeth with a wire permanently and you don’t have to worry about the wire showing off when you smile.
How much the retainer (any style) will cost is kind of dependent on where you live and how much the orthodontists in your area charge. The retainers won’t move your teeth back to where they were when the braces came off, just maintain them where they currently are. Do something sooner rather than later so that there’s no so much relapse. If you decide on permanent retainers remember that you have to floss under the wire, so you have to use those little floss threaders. This is really important – to keep the gums healthy.