SPONTANEOUS FORMATION OF BONELIKE APATITE LAYER ON CHEMICALLY TREATEDTITANIUM METALS

Generally, artificial materials implanted into bone defects are encaps ulated by a fibrous tissue isolating them from the surrounding bone. O nly limited kinds of ceramics are known to bond to living bone without forming the fibrous tissue, and already they are being used clinicall y as important artificial bones. However, they cannot be used under hi ghly loaded conditions, since their fracture toughnesses are not so hi gh as that of human cortical bone. The present study shows that even p ure titanium metal and its alloys can bond to living bone, if their su rfaces are pretreated with alkali hydroxide solutions. Thus-treated me tals are believed to be useful as artificial bones even under highly l oaded conditions because of their high bone-bonding ability as well as high fracture toughness.