Please choose the correct ending to complete the given sentence: Health: [header] How to heal hypertrophic scars [title] Apply a silicone gel or mask. [step] Silicone gel masks are a common, effective treatment for hypertrophic scars. You can buy sheeting masks or gel over-the-counter at a drug store or online, or you can purchase it from your dermatologist.

Ending1: Apply the gel or mask a few times a day for a week or two, for a total supply. [substeps] Silicone gel masks are the best for hypertrophic scars because they last for several months, and they stay in the skin for several months. Ending2: Carefully follow the instructions on the packaging, or those provided by your doctor. [substeps] To use the mask, apply it over your scar and make sure it stays in place. Ending3: This gel or mask is applied over the entire area of the acne on the face, burning away the dead skin cells and softening the scar skin. It can be pricey, so if you're not certain where to look, ask your dermatologist or pharmacist. Ending4: They may cause a burning sensation, but are safe and comfortable to apply directly to your skin. Silicone masks can leave nasty scars, so look for a product specifically designed for your needs.

Answer format: ending1/ending2/ending3/ending4