The effect of surface roughness on the stress adaptation of trabecular architecture around a cylindrical implant

The effect of implant-bone bonding and the effect of implant surface roughn ess on bone remodeling near the bone-implant interface were studied by usin g a surface remodeling theory and the boundary element method. The study ha s shown that implant attachment plays an important role in bone remodeling near the implant. It has been observed in animal experiments and in clinica l situations that the remodeled trabecular bone architecture around a cylin drical implant could vary, on one hand, from a hub surrounding the implant with a set of external spokes to, on the other hand, a hubless situation in which a set of spokes attach directly to the implant. It is shown here tha t the difference in these structures may be attributed to differences in im plant attachment. The results show that the bone with perfect bonding or ro ller boundary condition without a gap remodeled to a hubless spoke trabecul ar bone architecture. On the other hand, the roller boundary condition with a specified gap yielded a spoke trabecular architecture with a hub or ring surrounding the implant. These quantitative results mirror the experimenta l and clinical observations. It is concluded that the hub is a consequence of the gap and not a consequence of the lack of friction between the implan t and the bone. (C) 1999 Elsevier Science Ltd. All rights reserved.