[Long-lasting filling procedures].

A long-lasting filling product is accepted as such when, once the result has been obtained, no correction is required before the end of an arbitrary 2-year period. Other than silicone oil, which is not officially recognized for this indication in France, pure products can be distinguished from microparticle suspensions in a vector that will disappear in a short time. Flexible implants represent a totally separate entity and remain relatively little used since surgery is necessary for implantation. Our experience has led us to prefer monomolecular filling gels, in particular polyacrylamide hydrogels, with which we have had extensive experience, over gels with microparticles that we believe expose the patient to much greater inflammatory reactions that are sometimes difficult to overcome.