Can DermaRolling really cause thicker/tougher skin with long-term use?

I recommend physician supervised treatments because, as you know, derma rolling is being done to generate collagen which may thickness of the skin 

While micro-needling works by stimulating collagen production, it is really only enough to combat the appearance of the skin doe to collagen loss from aging. It should not cause scar tissue build-up.However, I recommend against using rollers such as the Dermaroller as they create a more erratic pattern of "tears" through the skin rather than the clean, more evenly distributed punctures seen with motorized micro-needling machines. Also, to get the best results micro-needling should be combined with the application of human growth factor serum which results in healthier collagen and elastic fibers.
In my office we are getting excellent results using the ProCell Therapies system which combines motorized micro-needling with concentrated human growth factor serums made from human stem cells. Our patients also use growth factor serums at home after their office treatment.