Silicone scar sheets are used to treat and prevent abnormal scars by hydrating the skin and creating a protective barrier. They are considered a first-line treatment for hypertrophic scars and keloids, helping to flatten, soften, and lighten them while relieving associated symptoms like itching, pain, and redness. The sheets work by regulating fibroblast activity, reducing excess collagen, and providing a controlled environment for skin healing.