Healing of rabbit calvarial bone defects using biphasic calcium phosphate ceramics made of submicron-sized grains with a hierarchical pore structure.
OBJECTIVE
This study investigated the efficacy of new bone graft substitutes - biphasic calcium phosphates (BCP) made of submicron-sized grains with fully interconnected wide-range micron-scale pores in two different macrodesigns: donut shaped with a 300-400 microm central macropore (n-BCP-1) or rod-shaped (n-BCP-2)--in the healing of rabbit calvarial defects, and compared their bone-healing properties with those of various commercial bone substitutes, which included substitutes with similar BCP composition (MBCP and Osteon), anorganic bovine bone (Bio-Oss), and beta-TCP (Cerasorb).


METHODS
The surface morphology of the bone substitutes was investigated using scanning electron microscopy (SEM). Defects 8 mm in diameter were created in the calvaria of 30 adult male New Zealand White rabbits and were filled with six types of bone substitutes. The percentage of newly formed bone (NB%) was evaluated histomorphometrically 4 and 8 weeks after implantation.


RESULTS
SEM observation showed submicron-sized grains with fully interconnected micropore structures in the n-BCP-1 and n-BCP-2 groups; these groups also showed considerable new bone formation in inner micropores as well as on the outer surfaces. The n-BCP-1 group exhibited enhanced new bone formation and direct ingrowth of bone tissue with blood vessels into central pores. Histomorphometric analysis showed significantly greater NB% in the n-BCP-1 group when compared with the other groups at 4 and 8 weeks (P<0.05).


CONCLUSIONS
A new BCP ceramics made of submicron-sized grains with a hierarchical pore structure was an effective osteoconductive material for the treatment of osseous defects of rabbit calvaria.
Park
Jin-Woo
JW
Department of Periodontology, School of Dentistry, Kyungpook National University, Daegu, Korea. jinwoo@knu.ac.kr
Kim
Eun-Suk
ES
Jang
Je-Hee
JH
Suh
Jo-Young
JY
Park
Kwang-Bum
KB
Hanawa
Takao
T
D000818:Animals; D001861:Bone Regeneration; D018786:Bone Substitutes; D002130:Calcium Phosphates; D002516:Ceramics; D008297:Male; D010316:Particle Size; D016062:Porosity; D011817:Rabbits; D011897:Random Allocation; D012886:Skull / Q000601:surgery
D018786:Bone Substitutes; D002130:Calcium Phosphates