The track marks will go away. I also get them in certain areas.
If you had three dermarolling sessions, the dermaroller has been used for three times only (unless they use a new one every time). It is highly unlikely that three rollings would completely blunt the needles. There is no way a medical spa could use the same dermaroller on several customers (they would lose their license or worse) so it has been used at most three times.
The advantage of home dermarolling is that you can always check your needles every time before you roll, and stop as soon as you feel that something is wrong. The skin's main purpose is to protect and that is why the skin is flexible but really tough and it is not easy for the needles to penetrate it. I recommend softening the skin prior to dermarolling (my answer is #3):
https://http://forums.owndoc.com/dermarolling-microneedling/How-to-soften-the-skin-before-needling /a>
We have rolled with our dermaroller over a cardboard box and the needles did not bend. The material of the needles (surgical steel) is hard but it can be bent (microneedling needles have to be thin and bending is better than breaking off, which would happen with harder materials).
Ideally, the needles of a dermaroller would be made from a material that doesn't bend at all, doesn't break and stays sharp forever. Such material doesn't exist in the consumer realm.
If the needs were for example from ceramics, they would not bend but they would break and the broken off fragments would stay inside your skin. That would be a complete disaster.
Surgical steel doesn’t break (#1 importance) and remains sharp for a reasonable time but it is not completely bend-proof material.
If you find a bent needle on your dermaroller and it is not bent really badly, push it back and you can continue using it.
Peony, I think it will all turn out OK.