additional projections may be provided if a plurality of projections are provided the projections may be symmetrical with respect to the central axis of the assembly 10 or alternatively may be non symmetrical in order to provide rotational alignment of the sections 12 14 as described above as a further option the projection or projections could extend from the support section and into respective recesses of the milling section moreover projections could extend from both the support section and the milling section into recesses of the other the projection 28 may also have shapes other than that shown in the drawings for example the projections may be in the form of fibers a machined surface a mesh surface a roughened surface or an irregular surface such as for example may be presented by upstanding shards of hardened restorative material as an additional option the projections may include pores or recesses for bond enhancement furthermore the projection s could have a longitudinal axis that extends perpendicular to the central axis of the assembly such as one or more projections in the shape of cross bars that extend across all or a portion of the diameter of the bonding surface 20 the method of making the milling section 14 may also vary from that shown in fig5 and 6 for example the channel 50 could be eliminated if desired and one or more recesses could be provided in the front face of the plunger portion 42 in order to provide space for the restorative material to form one or more projections the restorative material may.