Depressed scar filler is generally not permanent. If the skin is not completed dermal regeneration during the healing process after severe trauma, depressed scar will be formed, and if it affects the beauty, local skin flatness can be restored by depressed scar filler. However, due to different filling materials, the filling effect and maintenance time also differ. 1.Hyaluronic acid: Hyaluronic acid is a filling substance, if the skin surface has depressions and wrinkles, they can be filled by injecting hyaluronic acid. But hyaluronic acid can only last for 6-12 months, and it will be discharged gradually with the body’s metabolism, so it cannot be maintained permanently; 2, collagen: the market for injectable filler collagen is still immature. The body itself contains enough collagen, but with age, if you do not replenish enough collagen, the body’s collagen will gradually lose, so that the skin full of elasticity as well as fullness gradually dries out, and also grows wrinkles. If the patient has depressed scars, collagen can be used to fill them, but collagen will gradually be absorbed by the body, so it cannot be permanently maintained; 3. Autologous fat: If the skin has depressions or wrinkles, excess fat from the rest of your body can be extracted and filled into the area that needs to be filled. Since it is own fat, there is usually no rejection, but fat transplantation involves injection techniques, extraction technology, which has a great impact on the later survival. Professional physicians can achieve a 50% survival rate/each time, so multiple fillings are needed to achieve the desired effect, and this technology requires very high requirements for equipment, methods and physician skills.