Heterotopic bone formation around sintered porous-surfaced Ti-6Al-4V implants coated with native bone morphogenetic proteins.
OBJECTIVE
Coating endosseous dental implants with growth factors such as bone morphogenetic proteins (BMPs) may be one way to accelerate and/or enhance the quality of osseointegration. The purpose of this study was to investigate in the murine muscle pouch model whether sintered porous-surfaced titanium alloy implants coated with BMPs would lead to heterotopic bone formation around and within the implant surface geometry.


METHODS
Porous-surfaced dental implants were coated with partially purified native human BMPs, with or without a carrier of Poloxamer 407 (BASF Corp., Parsippany, NJ), placed in gelatin capsules and implanted into the hindquarter muscles of mice. Mice were euthanized after 28 days. Sections of retrieved specimens were subsequently prepared for morphometric analysis of bone formation using backscatter electron microscopic images.


RESULTS
Human BMPs, either with or without the carrier of Poloxamer 407, led to bone formation within and outside of the sintered porous implant surface. When the sintered implant surface region was subdivided into inner and outer halves, similar levels of bone ingrowth and contact were seen in the 2 halves. Evidence of bone formation to the depth of the solid implant core (i.e., the deepest level possible) also was seen.


CONCLUSIONS
Sintered porous-surfaced dental implants can be used as substrate for partially purified BMPs in the murine muscle pouch model. With the addition of these osteoinductive factors, the porous implant surface supported bone formation within the surface porosity provided, in some instances, all the way to the solid implant core. The addition of growth factors to a sintered porous surface may be an efficient method for altering locally the healing sequence and quality of bone associated with osseointegration of bone-interfacing implants.
Simon
Ziv
Z
School of Dentistry, University of Southern California, Los Angeles, California, USA.
Deporter
Douglas A
DA
Pilliar
Robert M
RM
Clokie
Cameron M
CM
D000497:Alloys; D000818:Animals; D019485:Bone Morphogenetic Proteins / Q000009:adverse effects*; D020099:Coated Materials, Biocompatible / Q000009:adverse effects; D004365:Drugs, Chinese Herbal; D006801:Humans; D008297:Male; D051379:Mice; D009999:Ossification, Heterotopic / Q000209:etiology*; D019736:Prostheses and Implants / Q000009:adverse effects*; D014025:Titanium / Q000009:adverse effects
D000497:Alloys; D019485:Bone Morphogenetic Proteins; D020099:Coated Materials, Biocompatible; D004365:Drugs, Chinese Herbal; C510023:osteoking; C031462:titanium alloy (TiAl6V4); D014025:Titanium