What Kind of Retainer After Braces is Better, Clear Plastic or Wire?

I have worked extensively with both types of retainers and I have found that clear retainers retain better. I will always try to use clear retainers but sometimes they are not the best choice for a given patient. Minor tooth movement can also be accomplished with clear retainers to correct minor relapses.

The two types of retainers that you mentioned are the most common types of retainers.  They both have advantages and disadvantages.  Some orthodontists primarily us the wire retainers (Called Hawley retainers, named after Dr Hawley from many years ago) because they have been around the longest.  I typically use Hawley retainers on the upper, mostly nights only, because I do a lot of expansion of narrow upper jaws to ideal.  The Hawley holds the expansion better than the invisible retainers do.  Invisible retainers hold individual tooth alignment better in many cases, especially on the lower front teeth.

All retainers are effective, wire retainers are more durable, clear retainers are more cosmetic and fixed retainers are permanently cemented behind the teeth. It is easily possible to add springs to the wired retainer to realign the teeth that have moved.