Bone repair of critical size defects treated with mussel powder associated or not with bovine bone graft: histologic and histomorphometric study in rat calvaria.

The objective of this study was to evaluate the bone repair of critical size defects treated with mussel powder with or without additional bovine bone. Critical size defects of 5 mm were realized in the calvaria of 70 rats, which were randomly divided in 5 groups - Control (C), Autogenous Bone (AB), Mussel Powder (MP), Mussel Powder and Bovine Bone (MP-BB) and Bovine Bone (BB). Histological and histomorphometric analysis were performed 30 and 90 days after the surgical procedures (ANOVA e Tukey p < 0.05). After 30 days, the measures of remaining particles were: 28.36% (MP-BB), 26.63% (BB) and 8.64% (MP) with a statistically significant difference between BB and MP. The percentage of osseous matrix after 30 days was, AB (55.17%), 23.31% (BB), 11.66% (MP) and 10.71% (MP-BB) with statistically significant differences among all groups. After 90 days the figures were 25.05% (BB), 21.53% (MP-BB) and 1.97% (MP) with statistically significant differences between MP-BB and MP. Percentages of new bone formation after 90 days were 89.47% (AB), 35.70% (BB), 26.48% (MP-BB) and 7.37% (MP) with statistically significant differences between AB and the other groups. Within the limits of this study, we conclude that mussel powder, with or without additional bovine bone, did not induce new bone formation and did not repair critical size defects in rat calvaria.