Influência da administração local de sinvastatina na reparação óssea em calvária de ratos

Orientação: Profa. Dra. Ana Lia AnbinderDissertação (Mestrado) - Universidade de Taubaté, Programa de Pós-graduação em Odontologia, Taubaté, 2008.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Made available in DSpace on 2019-05-22T18:38:39Z (GMT). No. of bitstreams: 1 Jimmy Cavalcanti Calixto.pdf: 1554360 bytes, checksum: 79efbb04deda61dad51c200d79dd20f8 (MD5) Previous issue date: 2008Resumo: Diversas alternativas terapêuticas têm sido propostas para a reparação de defeitos ósseos, associadas à cirurgia, como enxertos autógenos, alógenos e aloplásticos, plasma rico em plaquetas e alguns medicamentos. Recentemente foram publicados diversos trabalhos relatando correlação entre o uso de estatinas, medicamentos usados como redutores do nível de colesterol sangüíneo e neoformação óssea. O objetivo deste trabalho foi avaliar o efeito do tratamento local com sinvastatina na reparação de defeitos em calota craniana de ratos. Foram utilizados 48 ratos, nos quais foram confeccionados dois defeitos ósseos de 5mm de diâmetro, um em cada parietal. Os animais foram divididos em três grupos de acordo com o material utilizado no defeito: controle, em que o defeito não foi tratado; sinvastatina, esponja de colágeno embebida com sinvastatina; e carreador, esponja de colágeno e água destilada. O sacrifício ocorreu após trinta ou sessenta dias; as calotas foram removidas, submetidas a exames radiográficos e à preparação histológica de rotina, sendo então realizada análise densitométrica da área do defeito ósseo e histométrica da área de neoformação óssea, com auxílio de um programa computacional para análise de imagens. Os dados foram submetidos à ANOVA e teste t de Student. Tanto na análise densitométrica, como na histométrica, verificouse ausência de diferença estatística entre os três grupos, em cada período experimental. Aos sessenta dias, os animais do grupo controle apresentaram formação óssea superior que aos trinta dias, o que não aconteceu com aqueles que receberam sinvastatina ou apenas o carreador. Clinicamente, verificou-se formação de crosta necrótica nos animais do grupo sinvastatina. Concluiu-se, de acordo com a metodologia utilizada, que a sinvastatina administrada localmente prejudicou a reparação de defeitos experimentais em calvária de ratos.Abstract: Several therapeutic alternatives have been proposed for the healing of bone defects, associated to the surgery, like autogenous, allogeneous and aloplastic grafts, plasma rich in plaques and some drugs. Recently several works were published reporting correlation between the use of statins, drugs used to reduce the level of blood cholesterol, and bone neoformation. The aim of this work was to evaluate the effect of the treatment with simvastatin, locally administered, in the healing of rat calvarial bone defects. There were used 48 rats, in which there were made two bone defects of 5 mm of diameter, one in each parietal bone. The animals were divided in three groups according to the material used in the defect: control, in which the defect was not treated; simvastatin, sponge of collagen soaked with simvastatin; and carrier, sponge of collagen and distilled water. The sacrifice took place after thirty or sixty days; the skulls were removed, subjected to radiographic examinations and to the routine histological preparation, then histometric analysis of the area of the bone defect was carried out, with support of a software for analysis of images. The data were subjected to the ANOVA and test t of Student. Both in the densiometric and in histometric analysis, it was verified the absence of statistical difference between the three groups, in each experimental period. At sixty days, the control animals presented more bone formation than in thirty days, which did not happen with those who received simvastatin or just the carrier. Clinically, it was verified formation of necrotic crust in the animals of the simvastatin group. One concluded, according to the methodology used, that the simvastatin administered locally harmed the repair of experimental defects in calvaria of rats.Mestre em Odontologi

Influence of the association between simvastatin and demineralized bovine bone matrix on bone repair in rats

Simvastatin, a drug used to lower blood cholesterol, has been reported to have an anabolic effect on bone. The purpose of this study was to evaluate the influence of simvastatin and demineralized bovine bone matrix (DBBM) on the repair of rat calvarial defects. Defects of 5 mm were created in 64 rats, divided into four groups: no local treatment (control); treatment with DBBM (DBBM); treatment with a combination of simvastatin solution (2.2 mg/50 mu l) and DBBM (DBBMSIM-1); and treatment with simvastatin solution (0.5 mg/50 mu l) and DBBM (DBBMSIM-2). Animals were sacrificed on postoperative day 30 or 60, after which the calvariae were X-rayed and prepared for histomorphometric evaluation. The data were submitted to statistical analysis (p < 0.05). Xrays revealed that, on postoperative day 30, animals treated with a lower dose of simvastatin presented the lowest bone density, whereas on postoperative day 60 the use of simvastatin, regardless of the dose, resulted in lower density than that observed in control and DBBM group samples. Histomorphometric analysis revealed that, on postoperative day 30, both DBBM and DBBMSIM-1 had a negative impact on bone formation. on postoperative day 60, none of the combinations tested impaired bone repair. These results showed that the association between DBBM and simvastatin had a negative impact on bone repair

The influence of local administration of simvastatin in calvarial bone healing in rats

Some authors have associated the use of statins, hypolipidemic drugs, and new bone formation. The aim of this work was to evaluate the effect of locally administered simvastatin on bone healing. Bone calvarial defects 5 mm in diameter were made in 64 rats. The animals were divided into four groups according to the graft material: the control group, in which the defects were not treated, the SIM-1 group, which received a sponge of collagen soaked with simvastatin (2.2 mg/50 mu l), the SIM-2 group, which received a sponge of collagen soaked with simvastatin (0.5 mg/50 mu l), and the carrier (CAR) group, which received a sponge of collagen and water. The animals were sacrificed after 30 or 60 days. The skulls were removed, and radiographic clensitometry and histometric analyses of the bone defect area were performed. Local crust formation was clinically verified in SIM-1 and SIM-2 animals. After statistical analysis (p < 0.05) of bone area data, we observed no significant differences among the groups after 30 days. After 60 days, however, there was less bone formation in the CAR and SIM-2 groups. The SIM-2 group also presented with lower radiographic densities after 60 days. According to the methodology used, we conclude that locally administered simvastatin was detrimental to the repair of defects in the calvaria of rats. (C) 2010 European Association for Cranio-Maxillo-Facial Surgery.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq