or the removal of the prosthesis or a drill guide to promote bone ingrowth in the guide means 5 and in particular into the anchoring holes or pores 7 they may be coated by a tissue ongrowth promoting material like hydroxyapatite or sustained drug release substances as described in u s pat no 4 913 903 1990 inventors einar sudmann et al as outlined above a prosthetic element may by be anchored to living tissue by tissue ingrowth whether anchorage by bone or by fibrous tissue only will give the best long term results in patients has yet to be decided however the very best anchored u201c implant u201d in man and animals the tooth is anchored by fibrous tissue by multiple small collagen fibrils and such anchorage by fibrous tissue only has stood the test of millions of years fig3 illustrates a prosthetic implant for fibrous tissue anchorage as outlined above to hinder bone tissue ingrowth pores for fibrous tissue anchorage should preferably have a maximal diameter of less than 0 1 mm the pores 8 in fig3 are thus not drawn to scale the essential part is that the pores are oriented perpendicular fig3 a b or at any angle to the guide means 5 for the cutting tool the external opening of each pore or hole 8 may be pointed at the distal perimeter 9 acting as a miniature cutting device cutting the ingrown tissue therein on retrieval fig3 c 8 9 fig3 a shows an.