A preparation (10, 11,12,13) to be fixed to a
natural tooth part or tooth, in particular for the replacement of a load-bearing
tooth part, is for example a filling for a drilled-out tooth (1), a crown, bridge or
prosthesis to be placed on a tooth stub, or a tooth pin to be fixed in a
tooth root for fastening an artificial tooth, a bridge or a
prosthesis. The preparation has surface regions which consist of a material with
thermoplastic properties. The preparation (10, 11, 12,13) is designed in a manner such that it has oscillation properties with such low damping losses that for a
liquefaction of the material with
thermoplastic properties by way of oscillations there are local stress concentrations required, and in a manner such that such stress concentrations only occur in the region of the preparation surface. The preparation is positioned on a suitably prepared
natural tooth part in a manner such that the material with the
thermoplastic properties is in contact or may be brought into contact with the
dentin surface and / or enamel surface. The preparation is then made to mechanically oscillate and is simultaneously pressed against the
natural tooth part, whereby the material with the thermoplastic properties is at least partly liquefied and brought into intimate contact with the
dentin or enamel surface in a manner such that after solidification it forms a positive fit and / or material fit connection. Teeth restored with such preparations have a high stability and a long life, which in particular is attributed to the fact that the thermoplastic material, in contrast to cements used for the same purpose, shrinks less and has the ability to relieve
internal stress by creeping.