Healing of critical-size cranial defects in guinea pigs using a bovine bone-derived resorbable membrane.
OBJECTIVE
To investigate the healing of critical-size cranial bone defects (9-mm-diameter) in guinea pigs treated with a bovine bone-derived resorbable membrane.


METHODS
A sample of 42 guinea pigs was divided into test (n = 20), control (n = 20), and standard (n = 2) groups. A full-thickness trephine defect was made in the fronto-parietal bone of each animal. In the test group, the internal and external openings of the defect were each closed with a separate membrane, and the space between them was filled with blood clot and a central spacer. In the control group, the defect was filled only with the blood clot and spacer. At 1, 3, 6, and 9 months later, the calvarias (5 per period) for both the test and control groups were collected, fixed, radiographed, and histologically processed. The standard-group animals were sacrificed immediately after surgery and used to determine the initial size of defect radiographically. The areas of defects in the radiographs were measured with image-analysis software and were compared between groups and periods by multiple regression analysis with the Bonferroni correction.


RESULTS
At 1 and 3 months, newly formed woven bone was histologically observed in both test and control groups. Radiographically, this new bone occupied an average of 32% of the defect area at 1 month and 60% at 3 months in the test group. In the control group, 21% of the defect was filled at 1 month and 39% at 3 months. However, the differences between treatments were not statistically significant (P > .05). At 6 and 9 months, a significant increase in newly formed lamellar bone was seen histologically in both groups. Radiographically, for the test group, the new bone occupied an average of 82% of the defect area at 6 months and 96% at 9 months. For the control group, new bone composed an average of 45% of the defect area at 6 months and 40% at 9 months. The differences between the test and control groups were statistically significant at 6 and 9 months (P < .05). Complete or almost complete filling of the defect was observed in several cases.


CONCLUSIONS
It was concluded that the bovine bone-derived membrane is highly biocompatible and is able to promote good healing of critical-size defects in calvaria of guinea pig.
Taga
Márcio Luiz de Lima
ML
Department of Prosthodontics, Bauru Dental School, University of São Paulo, Bauru, SP, Brazil.
Granjeiro
Jośe Mauro
JM
Cestari
Tania Mary
TM
Taga
Rumio
R
D020341:Absorbable Implants; D000818:Animals; D001857:Bone Matrix / Q000637:transplantation; D001861:Bone Regeneration; D002417:Cattle; D048091:Guided Tissue Regeneration / Q000379:methods*; D006168:Guinea Pigs; D007091:Image Processing, Computer-Assisted; D020007:Implants, Experimental; D008297:Male; D008567:Membranes, Artificial; D010294:Parietal Bone / Q000601:surgery; D012044:Regression Analysis
D008567:Membranes, Artificial