Protocols for immediate or early loading strive for an increase either of primary stability, which can be achieved either through an optimized implant form or implant surface or/and optimized surgical preparation of the implant bed. Conversely, through the modification of the implant surface, an acceleration of the bony healing is intended to achieve an earlier osseointegration and therefore a faster acceptable secondary stability for successful loading. The authors conclude that the use of immediate loading still consists of a higher risk because of non-existing, not yet defined diagnostic criteria and can therefore not be recommended to the general practitioner. An acceptable measurement system may be available in the near future and help revolutionize the treatment concept in implant therapy.
Osseointegration is the result of a biologic response of the bony tissues to implants. For oral endosteal implants a three to six month healing period prior to loading is generally considered a pre-condition for optimal bone apposition to the fixture. This clinical protocol is based on work done by Branemark during the 1960's and 1970's when a final proposition for healing periods for implants of the upper and lower jaw, based on the evaluation of the surgical and periodontal failure rates, was defined (Brånemark et al, 1977  ). These protocols on Osseointegration periods were based on early, partially unfavorable experimental conditions while methods and implant types were continuously changing: