The Radiesse website says the product 'immediately replenishes lost volume and stimulates the production of your own natural collagen with results that can last a year or more in many patients. Over time, the gel is absorbed and the body metabolizes the CaHA microspheres leaving behind only your own natural collagen.' So I'm asking the question, does the Radiesse product last a year and the collagen last for a lifetime?If not a lifetime, how long does Radiesse induced collagen last? Many thanks.