O emprego da ressonancia do spin eletronico como tecnica auxiliar na determinacao do grau de mineralizacao do osso neoformado em modelos de cicatrizacao ossea guiada

Abstract

The mechanism of the bone formation as consequence of implant of materials are very important questions in the therapy of bone reconstruction. The subject of this work is the study of the bone regeneration by Electron Spin Resonance (ESR), that provides complementary information on the bone mineralization. Bone defects were made surgically in the calvarial of 27 rabbits divided in 3 groups: experimental groups (A and B) and control group (C). In the group A Polyurethane oclusive membranes were implanted; group B received polytetrafluorethylene membrane implant; and in the group C none membrane was used. After the periods of 30, 60 and 120 days, the animals were sacrificed and the calvarial bones were submitted to the radiographic, histological, histometric and ESR analysis. The statistical analysis (ANOVA) of the histometric results shows that the averages of the groups A and B did not present significant differences in the neoformation region in the border and center of the defect for the period of 30 days. In this period there is statistical difference in experimental gorups in comparison with control gorup in both regions os neoformation. In the periods of 60 and 120 days, the averages of the groups did not present significant differences. For the ESR results the averages of the neoformation region in the border of the defect did not show significant difference for the 3 gorups. However the averages presented statistical difference in the center of the defect. In the period of 60 days, the averages of the groups did not present statistical differences in the neoformation regions. For the period of 120 days, the average of the group A did not show significant difference when compared with the group B, however when both groups were compared with the control statistical difference was noted. In conclusion the ESR is able to evaluate the dynamic of the bone regeneration, supplying additional information of the bone remodeling process in relation of radiological and histological analysis. The histometric analysis, in the period of 30 days, and the ESR in the periods of 30 and 120 days, showed the efficiency of the mechanical barriers in the bone repair with the same performance for the Polyurethane and Polytetrafluorethylene membranes.