Mechanobiology of bone regeneration and bone adaptation to achieve stable long-term fixation of endosseous implants

The success or failure of the clinical application of endosseous implants lies in the adequacy of the host to establish and maintain osseointegration. Although the success rate for implants is generally high, failures still occur. Mechanical loading has been identified as an important factor for both early and late biological failure. These phenomena are studied here by means of a representative member of the endosseous implants family: the oral implants. Early biological failure is a process of bone regeneration that has mostly been studied during fracture healing in long bones. Different theoretical models aim to describe these observed processes and employ different mechanical and biological parameters to drive the regeneration process. Several of these models were implemented to simulate the process of periimplant tissue differentiation in an in vivo bone chamber. Qualitative agreements canbenotedbetweenthenumericallypredictedandexperimentallyobservedtissue patternsinthechamber.Latebiologicalfailurehasoftenbeenattributedtoinappropriate implant loading. Numerous animal experiments show a distinct influence of the various types of loading on bone adaptation. Theoretical models aim to capture these observations in mathematical expressions. From an anatomical finite element model the peri-implant only part of the marginal bone loss could be related to over