An insert for a dental prosthesis screwed onto an implant, in particular of the type having a superstructure and an implant to be integrated in the bone, which are reciprocally joined by a screw. The insert is composed of an element made of a damping material interposed between the coupling surface of the superstructure and the implant. With an insert according to the invention, a dental prosthesis screwed onto an implant is obtained, which reproduces the natural anchoring state of the tooth to the bone, so that the stress peaks on the superstructure are damped before being discharged onto the implant and consequently also onto the bone. An insert according to the invention also offers the advantage of sealing the contact area between the superstructure and the implant, thus preventing dangerous bacterial infiltrations.