Effect of a hydroxyapatite tricalcium phosphate alloplast on osseous repair in the rat calvarium.
BACKGROUND
Bony defects caused by periodontitis are often treated by regenerative therapy using autografts and/or allografts. Alloplasts, such as hydroxyapatite or ceramics, are also used as osteoconductive materials that serve as a scaffold for new bony ingrowth. The purpose of this study was to determine the effect of hydroxyapatite tricalcium phosphate (HA-TCP) on osseous repair in the rat calvarium.


METHODS
Forty-four adult male Harlan Sprague-Dawley rats were assigned to one of four treatment groups: HA-TCP macroporous disk, HA-TCP microporous disk, HA-TCP granules, and demineralized freeze-dried bone (DFDB). The materials were placed into 8-mm calvarial critical-size defects (CSD). Calvariae were harvested at 10 weeks post-surgery and evaluated histomorphometrically.


RESULTS
The DFDB group had significantly (P <0.05) more new bone formation (47%) than any other group. The HA-TCP macroporous disk group had significantly (P <0.05) more new bone formation (19.7%) than the HA-TCP microporous disk (8.5%) or HA-TCP granule (6.9%) groups.


CONCLUSIONS
The HA-TCP macroporous disk may elicit significant new bone formation due to its rigid space-maintaining scaffold and pore size for vascular ingrowth. It is well tolerated by host tissues and may be a suitable carrier for growth factors.
U.S. Army, Fort Bragg, NC, USA.
Kurt B
KB
Fleckenstein
Michael F
MF
Cuenin
Mark E
ME
Peacock
Michael A
MA
Billman
Gary D
GD
Swiec
Thomas B
TB
Buxton
Baldev B
BB
Singh
James C
JC
McPherson
D000818:Animals; D001847:Bone Diseases / Q000473:pathology / Q000601:surgery*; D018786:Bone Substitutes / Q000627:therapeutic use*; D016025:Bone Transplantation / Q000379:methods; D002130:Calcium Phosphates / Q000627:therapeutic use*; D004195:Disease Models, Animal; D006882:Hydroxyapatites / Q000627:therapeutic use*; D008297:Male; D008567:Membranes, Artificial; D008855:Microscopy, Electron, Scanning; D010012:Osteogenesis / Q000502:physiology; D010316:Particle Size; D011138:Polytetrafluoroethylene; D016062:Porosity; D011897:Random Allocation; D051381:Rats; D017207:Rats, Sprague-Dawley; D019651:Plastic Surgery Procedures; D012886:Skull / Q000473:pathology / Q000601:surgery*
D018786:Bone Substitutes; D002130:Calcium Phosphates; D006882:Hydroxyapatites; D008567:Membranes, Artificial; C074950:hydroxyapatite-beta tricalcium phosphate; D011138:Polytetrafluoroethylene