Dr. John Davies, Toronto, ON

Clinical osseointegration is the anchorage of an implant in bone sufficient to withstand occlusal loading.

But, from a scientific perspective, osseointegration represents a multiplicity of biologic processes that can be broadly divided into three phenomena: osteoconduction, bone formation and bone remodeling. Osteoconduction is defined as the recruitment and migration of osteogenic cells to the implant surface – but important questions are: “Where do they come from?”, “How do they get to the implant surface?”, “Does the implant surface play a role in this biology?” and “Are there other early biologic processes that are influenced by implant surface design?” It is particularly important to be able to differentiate this healthy healing biology from that which happens in peri-implantitis for two reasons. First, peri-implantitis has become increasingly common with the advent of topographically complex implant surface designs. Second, one of the most recent definitions of osseointegration conflates normal healing and peri-implantitis.

Learning Objectives:

1) To understand the three major phenomena that comprise osseointegration.

2) To realize that implant surface design has a profound effect on peri-implant wound healing

3) To be able to critically evaluate the most recent definition of the term “osseointegration”.

Bio:  Davies, who trained as an oro-maxillo-facial surgeon, is a Professor of Dentistry and Biomaterials at the University of Toronto. Davies received the degree of Doctor of Science (D.Sc.) from the University of London, in 1998, for his sustained contributions, over a period of 20 years, to the field of Biomaterials, and was the 2002 recipient of the Society for Biomaterials Clemson Award for Basic Science. He was elected a Fellow of Biomaterials Science and Engineering (FBSE) in 2000. In the mid-80’s, he devised the first in vitro biological methods to study the mechanisms of bone bonding to bioactive ceramics. His work has led to an understanding of the mechanisms by which bone grows on implant surfaces and within tissue engineering scaffolds. He has developed ceramics that can be resorbed by osteoclasts (This technology has also been adopted by the Canadian Space Agency to investigate the cellular mechanisms of microgravity-induced osteopenia. See the tomorrow-Today website for a feature article about Bone Loss in Zero Gravity.), calcium phosphates that stimulate increase in local bone mass, scaffolding materials for bone regeneration, and extra-embryonic cells as a potential source of cell-based connective tissue repair.