Fillers are a temporary way to fill in depressed scars. Restylane can last about 6-9months, and radiesse 1-2 years. Fat can be another option to fill in scars and can last many years like 10 years give or take a few years when done right. In my experience, using temporary fillers gives one only modest results and most people are left desiring more improvement. Other ways to lift the scar include subscision technique where you use a needle to lift the scar up so that it sits level with the plane of the rest of the skin. This can be done in conjunction with laser resurfacing. Other ways to lift up the scar is to use biopsy instruments to incise around the depressed scar and this is then lifted up into the right plane. Another way is to cut the scar out and follow this with resurfacing.