Morphometric evaluation of the repair of critical-size defects using demineralized bovine bone and autogenous bone grafts in rat calvaria.
OBJECTIVE
To evaluate the repair of critical-size bone defects in rats treated with demineralized bovine bone (DBB) compared with autogenous bone (AB).


METHODS
A bone defect of 8 mm in diameter was created in the calvaria of 50 Rattus norvegicus, treated either with DBB or AB. Sub-groups of five rats of each group were killed at 7, 14, 21, 30 and 90 days post-operatively, and the skulls were removed and processed histologically. Histological sections were stained with hematoxylin and eosin.


RESULTS
Histological analysis showed complete closure of the defects with new bone at 90 days in group AB, and substitution of the biomaterial by fibrotic connective tissue in the DBB group at 21 days. Morphometric analysis showed that DBB was rapidly absorbed at 14 days, with its volume density decreasing from 47%+/-0.8% at 7 days to 1.2%+/-0.41% at 14 days. Subsequently, volume densities of the connective tissue and neoformed bone increased from 51.1%+/-11.17% to 86.8%+/-7.92% and from 1.9%+/-1.13% to 12%+/-8.02%, respectively, for the same time interval. The volume density of AB particles did not change throughout the experimental periods, but the amount of new bone increased markedly between 7 and 90 days, from 4.5%+/-1.57% to 53.5%+/-6.42% (P<0.05).


CONCLUSIONS
DBB did not provide complete repair of the defects, with significantly less new bone formation than in the AB group.
de Oliveira
Rodrigo Cardoso
RC
Institute of Biology, UNICAMP, Bauru Dental School, University of São Paulo, Brazil.
de Oliveira
Fabio Henrique Gelonese
FH
Cestari
Tânia Mary
TM
Taga
Rumio
R
Granjeiro
José Mauro
JM
D020341:Absorbable Implants; D000818:Animals; D001672:Biocompatible Materials / Q000627:therapeutic use; D001857:Bone Matrix / Q000502:physiology*; D001861:Bone Regeneration / Q000187:drug effects*; D018786:Bone Substitutes / Q000627:therapeutic use*; D016025:Bone Transplantation / Q000379:methods*; D002417:Cattle; D003399:Craniotomy / Q000379:methods; D008297:Male; D010012:Osteogenesis / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D012886:Skull / Q000187:drug effects / Q000502:physiology / Q000601:surgery*; D013997:Time Factors
D001672:Biocompatible Materials; D018786:Bone Substitutes