The number of available filling agents has increased dramatically, improving the range of options available to select from. Getting some information about the different characteristics, capabilities, risks, and limitations of the varying options can help an informed consumer understand what results they can expect and how much risk they face in terms of potential complications.
Fillers are classified as temporary/nonpermanent, semi-permanent, or permanent. Temporary fillers stay in the tissue for less than a year, semi-permanent fillers for up to one or two years, and permanent fillers are substances that remain in the tissue more than two years (so technically, they’re not really permanent). Beyond their permanent versus nonpermanent status, fillers are also classified by their source: human, animal, or synthetic.
Nonpermanent and semi-permanent fillers have the disadvantage of spontaneously disappearing so they have to be redone every six months to two years to maintain the effect. Ironically, the advantage of nonpermanent and semi-permanent fillers is that if any problems do arise they dissolve in a relatively short period of time. Permanent fillers obviously have the advantage of not requiring additional treatments for many years if at all, but if there are complications with these the problem(s) may not resolve on their own and could even require surgical removal if rare, serious problems occur. In terms of risk, rare, long-lasting side effects have been reported even with temporary fillers.
(Sources: Journal of Plastic, Reconstructive and Aesthetic Surgery, January 2009, pages 11-18; and Journal of Oral Implantology, April 2007, pages 191-204.)