I have boxcar scars similar to those in the attached picture. I have undergone 6 TCA cross treatments. First treatment yielded amazing results, with decreasing efficacy with each successive treatment. 1. Why has the effectiveness of the TCA cross treatments decreased? Is it because the remaining scar tissue is too deep? What is the penetration depth of TCA cross? 2. Fraxel repair has a penetration depth of ~1.6mm. Would Fraxel Re:Pair Dual reach the scar tissue that TCA cross could not?