The invention relates to implants which are based on a biodegradable thixotropic compound having pseudoplastic properties and which can be injected subcutaneously or intradermally into the fibrous tissue. The inventive implant comprises microparticles of at least one biocompatible ceramic compound which are suspended in a vector fluid containing at least one hyaluronic acid-based compound and at least one biodegradable thixotropic compound having pseudoplastic properties. The invention also relates to a kit for the extemporaneous use of such implants, the production of said implants and the use thereof in order to fill wrinkles and/or fine lines and/or cutaneous depressions and/or scars.