Efeito da associação da doxiciclina com enxerto autógeno particulado no reparo ósseo: estudo histomorfométrico em calvária de ratos

Abstract

The aim of the study was to evaluate, descriptively and histologically the effect of association of 10% doxycycline in natrosol gel with autogenous bone on bone repair of simulated critical-size defects in rat calvaria. A total of fifty albino rats were selected. A 5-mm diameter defect was created in the calvarium of each animal. The animals were divided into 5 groups (n = 10) according to the material used to fill the defect: G1 – Defect unfilled (CO - blood clot/ control); G2 – 10% Doxycycline in natrosol gel (DOX); G3 – Natrosol gel (NAT); G4 – Autogenous bone (OA) and G5 – Autogenous bone associated with 10% Doxycycline in natrosol gel (OA + DOX). The animals were killed at 4 and 8 weeks postoperatively. Qualitative and quantitative analyses were performed. The amount of new bone formed was calculated as a percentage of bone inside the total area of the original defect. Statistical analysis was performed using ANOVA and Tukey tests (p < 0.05). New bone formation was limited to the margins of the defect with no complete bone repair for all groups. At 4 and 8 weeks of analysis, the group OA + DOX showed high percentage of bone formation (38.59% and 47.86%, respectively), with statistical difference in comparison with the group CO (19.52%) at 4 weeks and with the groups CO (18.80%), DOX (22.05%) and NAT (15.89%) at 8 weeks (p < 0.05). The study suggest that the association of 10% doxycycline with autogenous bone improve significatively bone healing in critical-size defects in rat calvaria in comparison to defects not filled (CO) and filled with DOX and NAT.