The bone-regenerative properties of Emdogain adsorbed onto poly(D,L-lactic-coglycolic acid)/calcium phosphate composites in an ectopic and an orthotopic rat model.
OBJECTIVE
The aim of this study was to evaluate the bone-regenerative properties of Emdogain in osseous and nonosseous sites.


METHODS
For the orthotopic study, unloaded poly(D,L-lactic-coglycolic acid)/calcium phosphate implants, and poly(D,L-lactic-coglycolic acid)/calcium phosphate implants loaded with different concentrations (0.25, 0.50 or 0.80 mg per implant) of enamel matrix derivative (EMD), were inserted into cranial defects of 24 rats. The implantation time was 4 wk. For the ectopic study, 32 implants were placed subcutaneously. The same study period and groups as in the orthotopic study were used. Methods of evaluation consisted of descriptive histology, histomorphometry and an in vitro EMD-release study.


RESULTS
In the orthotopic study, new bone formation was most abundant in unloaded implants followed by 0.50-mg EMD composites. Histomorphometric measurements showed 54 +/- 15.0% bone ingrowth for unloaded implants, 19 +/- 22.5% bone ingrowth for 0.25-mg EMD composites, 40 +/- 23.6% bone ingrowth for 0.50-mg EMD composites and 26 +/- 17.6% bone ingrowth for 0.80-mg EMD composites. Light microscopic analysis of the subcutaneous sections from the ectopic study revealed no bone formation in any group after 4 wk. The in vitro release study showed 60% cumulative EMD release after 4 wk.


CONCLUSIONS
Emdogain is not osteoinductive and is not able to enhance bone healing in combination with an osteoconductive material, such as poly(D,L-lactic-coglycolic acid)/calcium phosphate cement.
Plachokova
A S
AS
Department of Periodontology and Biomaterials, Radboud University Nijmegen Medical Center, Nijmegen, The Netherlands.
van den Dolder
J
J
Jansen
J A
JA
D000818:Animals; D001861:Bone Regeneration / Q000187:drug effects*; D018786:Bone Substitutes / Q000627:therapeutic use*; D002130:Calcium Phosphates / Q000627:therapeutic use*; D003746:Dental Enamel Proteins / Q000627:therapeutic use*; D004338:Drug Combinations; D006016:Glycolates / Q000627:therapeutic use*; D019344:Lactic Acid; D008297:Male; D008863:Microspheres; D011100:Polyglycolic Acid; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D019736:Prostheses and Implants; D051381:Rats; D012886:Skull / Q000601:surgery
D018786:Bone Substitutes; D002130:Calcium Phosphates; D003746:Dental Enamel Proteins; D004338:Drug Combinations; D006016:Glycolates; C109069:enamel matrix proteins; D000077182:Polylactic Acid-Polyglycolic Acid Copolymer; D011100:Polyglycolic Acid; D019344:Lactic Acid; C020243:calcium phosphate