RESUMO
A kinetic study of the in vivo degradation of sepiolite-collagen complexes after subcutaneous implantation in rats was performed. A foreign-body reaction was the characteristic host tissue response against the implants. The resorption of the implanted materials was analyzed by measuring both the weight and the collagen persistences. This last was measured by using (14C)acetylated collagen, which was revealed to be not modified upon radioactive labeling, in terms of its ability to form a complex with sepiolite. The persistence of the implants is controllable by treatment of the collagen component with glutaraldehyde. Thus, for 1% glutaraldehyde-treated collagen complexes, 100% of persistence was observed after several months of implantation, this value decreasing to a few days for nontreated collagen samples. The collagen-sepiolite complex showed a low immunological response, almost null for 1% glutaraldehyde-treated collagen complexes, which was analyzed by measuring anti-collagen antibodies levels. Based on the performed studies, sepiolite-collagen complexes can be considered a resorbable material.
Assuntos
Materiais Biocompatíveis/química , Colágeno/química , Glutaral/química , Silicatos de Magnésio/química , Animais , Formação de Anticorpos/imunologia , Materiais Biocompatíveis/efeitos adversos , Dicroísmo Circular , Colágeno/efeitos adversos , Colágeno/imunologia , Colagenases , Cricetinae , Eletroforese em Gel de Poliacrilamida , Reação a Corpo Estranho/imunologia , Glutaral/efeitos adversos , Glutaral/imunologia , Hidrólise , Cinética , Silicatos de Magnésio/efeitos adversos , Silicatos de Magnésio/imunologia , Masculino , Próteses e Implantes , Ratos , Ratos WistarRESUMO
A case of metastatic bronchogenic carcinoma to the gingiva in a 47-year-old male is reported. The gingival lesion developed as a quickly growing mass and appeared 2 months after surgical excision and radiotherapy of the lung carcinoma were completed. The gingival tumor was histopathologically diagnosed as a poorly differentiated squamous carcinoma. Comparative cytologic studies showed similarities between the gingival metastasis and the previous lung cancer.
Assuntos
Carcinoma Broncogênico/patologia , Carcinoma Broncogênico/secundário , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/secundário , Neoplasias Gengivais/secundário , Neoplasias Pulmonares/patologia , Antígenos de Neoplasias/análise , Neoplasias Gengivais/patologia , Humanos , Queratinas/análise , Masculino , Pessoa de Meia-Idade , Mitose , Mucina-1/análise , Proteínas de Neoplasias/análiseRESUMO
The response of osseous tissue to the implantation of sepiolite-collagen complexes has been studied. Sepiolite, sepiolite-collagen complex and 0.5% glutaraldehyde-treated sepiolite-collagen complex were implanted in created circular defects in rat calvaria. The tissue reactions were analysed using light, transmission and scanning electron microscopies. The patterns of bone growth were radiographically analysed and the bone activity was indirectly quantified by using a point-count method. The reaction against the three implanted materials is characteristic of a foreign body reaction with abundant macrophages and giant cells. Implanted products have been detected in macrophages, which suggest the involvement of phagocytosis in the resorptive process. Bone grew at the implantation sites originating excrescences or sometimes a thin bridge at the defect margins. The studied materials, after implantation in contact with bone tissue, did not produce any toxic effect or necrosis, allowing bone activity.
Assuntos
Regeneração Óssea/efeitos dos fármacos , Colágeno/metabolismo , Granuloma de Corpo Estranho/patologia , Silicatos de Magnésio/metabolismo , Crânio/efeitos dos fármacos , Animais , Materiais Biocompatíveis , Colágeno/efeitos adversos , Colágeno/farmacologia , Modelos Animais de Doenças , Células Gigantes/efeitos dos fármacos , Células Gigantes/metabolismo , Glutaral/química , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Silicatos de Magnésio/efeitos adversos , Silicatos de Magnésio/farmacologia , Masculino , Microscopia Eletrônica , Microscopia Eletrônica de Varredura , Próteses e Implantes , Radiografia , Ratos , Ratos Wistar , Crânio/diagnóstico por imagem , Crânio/lesões , Crânio/ultraestruturaRESUMO
A cementifying fibroma associated with a large intraosseous periodontal defect is reported. This tumor was located in the lingual aspect of the first lower left molar. Therapy consisted on flap surgery, tumor excision, and placement of a bone autograft in order to fill the residual bone defect. Six months after the treatment, clinical and radiographic signs of periodontal regeneration were evidenced.
