Use Derma Rollers on scars to help heal them.

"A dermaroller is a skin needling device with many small surgical needles. Dermarollers come in needle lengths between 0.13 and 3 mm. The needle diameter (thickness) is approximately 0.25 mm at their base."
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More Info..

1. Beauty School: How to Use a Derma Roller @MichellePhan.com
2. Derma Roller: DONE RIGHT!! Safe, Effective, Results uploaded by Kim Sevy 
3. How to Use a Derma Roller for Acne Scars Micro Needling uploaded by Hafsa 
4. Derma Roller Worth it? Reviews, Cost, Pictures \@ RealSelf
5. Derma Roller on Self Harm Scars @ Tumblr