Osseointegration is the key biologic and biophysical process that has made dental implant therapy predictably effective for replacing missing teeth. Histologically defined, osseointegration is the direct structural and functional connection between organized, living bone and the surface of a load-bearing implant without intervening soft tissue between the implant and bone. The discovery of this process occurred by accident when Swedish bone researchers placed chambers into the bone of animals to examine the vasculature of the bone.

From http://kianorshahmohammadi.com/post/156176938255

From https://dentaleconomicsus.wordpress.com/2017/01/21/section-ii-biologic-considerations/