Mixto Fractional CO2 Vs Matrix RF Laser for Ice Pick Scars?

I'm considering doing laser treatment for my ice pick scars. I wonder what the difference between Mixto Fractional CO2 and Matrix RF laser is and which experiment is the most effective for a better result? And will it become permanent or just last for a few years? Also would I like to know if one session could be enough, since I have only one area that is very deep, but on the other areas they are more shallowed and medium deep.