Pictures in the cover: Upper one by T Waris, middle and lower pictures by T Talasmaa & N Ashammakhi. Art executive: L Torniainen, CDQ Solutions Ltd. Cover design: N Ashammakhi. Abstract book organised by Y Konttinen & N Ashammakhi. © Center of Excellence 2004 Sponsored by Linvatec Biomaterials Oy and Tampere, Bioretec Oy, Tampere