Osteoconductive effects of 3 heat-treated hydroxyapatites in rabbit calvarial defects.
OBJECTIVE
This study aimed to detect the osteoconductive ability of 3 bovine hydroxyapatites (HAs) that were sintered at 800 degrees C (HA800), 1,200 degrees C (HA1200), and 1,350 degrees C (HA1350), according to new bone formation.


METHODS
Two bicortical skull defects were prepared in 10 New Zealand white rabbits. Four rabbits were used as controls; in each, 1 defect was filled with autogenous bone chips and the contralateral defect was left empty for the critical size defect (CSD). The other 6 rabbits had a total of 12 defects, 4 each randomly filled with HA 800, HA1200, or HA1350. The animals were sacrificed at 8 weeks. New bone formation was assessed by radiographic densitometry and histomorphometric analysis.


RESULTS
The mean optical density (OD) of the CSD group (0.092 +/- 0.006) was less than that of the autogenous bone chip (0.102 +/- 0.002), HA1200 (0.108 +/- 0.005), and HA 1350 (0.102 +/- 0.003) groups. The mean OD of the HA 1200 group was significantly different from that of the HA 800 group (0.094 +/- 0.003). The histomorphometric analysis demonstrated that the autogenous bone chip group (34.89 +/- 4.61) was significantly different from the CSD (12.16+/- 6.97), HA 800 (18.32 +/- 7.33), and HA1350 (13.99 +/- 3.94) groups, but not the HA1200 group (24.83 +/- 12.12).


CONCLUSIONS
The findings demonstrate that heat-treated bovine HA enhances bone formation, and HA 1200 tends to provide greater bone formation than the other 2 HAs.
Pripatnanont
Prisana
P
Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Prince of Songkla University, Hatyai, Songkla, Thailand.
Nuntanaranont
Thongchai
T
Vongvatcharanon
Surapong
S
Limlertmongkol
Supakit
S
D000818:Animals; D001861:Bone Regeneration / Q000502:physiology*; D018786:Bone Substitutes / Q000737:chemistry / Q000627:therapeutic use*; D016025:Bone Transplantation / Q000000981:diagnostic imaging / Q000379:methods / Q000502:physiology; D002417:Cattle; D017886:Durapatite / Q000627:therapeutic use*; D006358:Hot Temperature; D007091:Image Processing, Computer-Assisted / Q000295:instrumentation / Q000379:methods; D008297:Male; D023421:Models, Animal; D011817:Rabbits; D011859:Radiography; D012886:Skull / Q000000981:diagnostic imaging / Q000601:surgery* / Q000648:ultrastructure
D018786:Bone Substitutes; D017886:Durapatite