Despite the recent advances in industrial medical research, there is no ideal filler available. The ideal material for filling would need to meet certain criteria to be accepted by the medical community, such as being easy to apply, non-toxic, non-carcinogenic, non-immunogenic, and promoting a good cosmetic outcome. Currently, silicone-based products, polyalkylimide, polyacrylamide and polymethyl methacrylate (PMMA) are available on the world market. Of the permanent fillers available, only two are registered with ANVISA (Agência Nacional de Vigilância Sanitária, the Brazilian National Health Surveillance Agency) for use in Brazil: polyacrylamide and PMMA (Rorich et al. 2009; Casavantes 2004).