Advances in Dental Research, Vol 13, 27-33, Copyright © 1999 by International & American Associations for Dental Research
The biologic tissue responses to uncoated and coated implanted biomaterials
D. E. Steflik, R. S. Corpe, T. R. Young, A. L. Sisk and G. R. Parr
Section of Orthopaedic Surgery, Department of Surgery, School of Medicine, Medical College of Georgia, Augusta, Georgia 30912-4030, USA.
Ultrastructural examination of the morphology and morphometry of the bone
supporting uncoated titanium and ceramic implants was assessed in an
experimental animal model involving 120 implants placed into the mandibles
of 30 adult mongrel dogs. Further, preliminary morphologic and morphometric
observations of the bone supporting uncoated and hydroxylapatite-coated
endosteal titanium implants was evaluated in a second investigation
involving 72 implants placed into the mandibles and maxillae of 6
additional dogs. A densely mineralized collagen fiber matrix was observed
directly interfacing with uncoated implants. The only material interposed
between the implant and bone matrix was a 20- to 50-nm electron-dense
material suggestive of a proteoglycan. Also seen in these same
osseointegrated implants were narrow unmineralized zones interposed between
the implant and bone matrix. In these zones of remodeling bone, numerous
osteoblasts were observed interacting with the collagen fiber matrix. It
was shown that a normal homeostasis of anabolic osteoblastic activity and
catabolic osteoclastic activity resulted in bone remodeling and the
resultant osseointegration of the implants. Hydroxylapatite-coated implants
intimately interfaced with healthy bone. The mineralized matrix extended
into the microporosity of the HA coating. This matrix contained viable
osteocytes.
