Branemark's Theory of Osseointegration
In 1952, Swedish orthopedic surgeon, Branemark, conducted microscopic studies done in situ of the bone marrow in rabbit's fibula with in vivo vital microscopic technique. Implanted titanium chambers containing an optical system for transillumination were used. However, these titanium chambers were not retrievable as they had fused with the surrounding bone. Further study revealed that titanium metal was biocompatible and had actually integrated with the bone and thus he called this process as osseointegration.
Branemark proposed that implants integrate such that the bone is laid very close to the implant without any intervening connective tissue. The titanium oxide permanently fuses with the bone. Branemark also stated that the implant should not be loaded and left out of function during the healing period for osseous integration to occur.