Análise histológica de enxertos ósseos autógenos fixados nas extremidades com etilcianoacrilato comparados com enxertos fixados com parafuso de titânio na região central: um estudo experimental em ratos

Abstract

Autogenous onlay bone grafts are widely used in the reconstruction of atrophic alveolar ridges. Recently, etilcianoacrilate was suggestesfor fixing autogenous bone onlay graft. The aim of this study was to perform a qualitative and semiquantitative histological analysis of autogenous bone grafts in the calvaria of rats fixed with etilcianoacrilate adhesive and titanium screw for 30 days. Fourteen Rattus novergicos Albinus (Wistar) underwent onlay parietal bone autografts fixed with etilcianoacrilate (Superbond Gel ® Flex ® - SB, n = 7) only in the edges and titanium screw in the center (n = 7). After 30 days, the animals were euthanized and the samples removed for histological analysis. After decalcification, the specimes were stained with hematoxylin and eosin. The graft vitality to the presence of osteocytes was analyses in the both groups. The interface was evaluated for the presence of: the adhesive (SB), tissue reaction with formation of osteoid matrix, bone resorption, formation of capillary, inflammatory infiltration, fibroblast proliferation, osteoblasts, osteocytes and osteoclasts. Statistical analysis of the results by SPSS Statistic 15.0 ® software and nonparametric tests were performed. Mann-Whitney and Fisher's exact test were used for comparison between groups. Wilcoxon test and McNemar were used for intragroup comparisons (p - value < 0.05). In qualitative assessments, no statistically significant differences were found. A significant difference was found in the intergroup comparison for the quantitative evaluation: the central region of the PT group presented more osteocytes (p = 0.035), increased inflammation (p = 0.030) and more osteoclasts (p = 0.048) were observed in the edges of the SB group. When comparing the central regions and the edges of the grafts, PT group demonstrated more bone formation in the central region. The SB groups showed no osseointegration on the graft. At 30 days in the PT group the graft was only partially integrated to the host bed.