Cosmetic dermal fillers fall into three classes: short-acting hyaluronic acid fillers like Restylane, Juvederm and Perlane; intermediate-acting fillers like Radiesse; and long-acting or permanent fillers like Gore-Tex, silicone or Artefill. Advantages associated with hyaluronic acid fillers are that they can be used for lip enhancement, and they are reversible if the cosmetic result does not turn out as expected. Radiesse dermal filler is very versatile and can be used anywhere (except lips) to augment cheekbones, improve wrinkles, scars, or the shape of the nose, and even to enhance the backs of the hands. Duration of Radiesse filler can vary from one to two years or more. Permanent fillers are just that: permanent. If the cosmetic result is good, the procedure should not have to be repeated; however the product is not easily removed once injected into the skin, so clients should research carefully the skills and patient testimonials of any practitioner who they plan to have do this work.