None of these treatments is likely to remove all your son's scars. However, it may indeed be possible to smooth many of them out, perhaps after 2 or 3 sessions.
The CO2 laser is most likely to give meaningful results. Newer lasers that fractionate the beam (like the Fraxel) result in much less "down-time," meaning shorter healing periods. It may, however, take more sessions to achieve the maximum result.
Dermabrasion is an operative procedure that is more like traditional (non-fractionated) CO2 resurfacing. In experienced hands, it can be quite effective, but it's pretty intense.
There is no correct answer to the question of what is best. It depends on the doctor, and the lasers with which he or she is familiar. I'd get 2 or 3 opinions from reputable people and then go with the one you feel most comfortable with overall, just as you would do if you were considering any kind of surgery and had the time to look into it.
Best.
Dr. Rockoff
A combination of treatments can greatly reduce the amount and severity of acne in many cases. Those treatments that are most effective tend to have greater potential for side effects and need a greater degree of monitoring, so a step-wise approach is often taken. Many people consult with doctors when deciding which treatments to use, especially when considering using any treatments in combination. There are a number of treatments that have been proven effective:
Read more www.justyourdoc.com