There are a few different tools that can break up scar tissue, but the most common and effective one is called a derma roller. A derma roller is a small, hand-held roller that has dozens of tiny needles on it. When you roll the derma roller over your skin, the needles puncture the top layer of skin and create tiny wounds. This triggers your body's natural healing process, which causes new collagen and elastin to be produced. This new collagen and elastin help to fill in the scars and improve the appearance of your skin.