RESUMO
OBJECTIVE: It is necessary to preserve height and thickness of the alveolar bone to facilitate rehabilitation with osteointegratable implants or simply to maintain bone integrity after extraction. Biomaterials associated with resorbable or non-resorbable membranes, when placed in the region of the socket, may contribute to avoid this unwanted reabsorption. OBJECTIVE: The objective of this study was to evaluate the distance of the crest of alveolar ridge to the cementoenamel junction (CEJ) of the lower second molars and the bone density of the third molar socket filled with Gen-Tech®, 5 years after an exodontia using cone beam computed tomography (CBCT) to visualize the central region of the sockets, without overlapping of the buccal and lingual cortical bones. MATERIAL AND METHODS: A total of 12 individuals from an initial group of 39 patients submitted to extraction of the unruptured lower third molars and grafting of an association of inorganic bovine bone matrix, organic bovine bone matrix, collagen and bone morphogenetic proteins (BMP) (Gen-Tech®) on one side and the contralateral sockets filled only by clot, returned to control after 5 years, and were submitted to CBCT. The distance from the crest of alveolar bone to the CEJ and the bone density (BD) were measured using the i-CAT Vision Software. RESULTS: The results showed that the distance from the crest of alveolar bone to the CEJ in the control group was similar to that observed before the exodontia; in the experimental group, this distance was smaller. Considering the BD measurement, a significantly higher density was observed in the experimental group (p<0.05). CONCLUSION: Part of the biomaterial was not absorbed and allowed the stability of the evaluated parameters after 5 years, being able to be used as a bone substitute in the socket.
Assuntos
Substitutos Ósseos , Transplante Ósseo/métodos , Xenoenxertos/diagnóstico por imagem , Dente Serotino/diagnóstico por imagem , Colo do Dente/diagnóstico por imagem , Alvéolo Dental/diagnóstico por imagem , Dente Impactado/diagnóstico por imagem , Adolescente , Adulto , Animais , Densidade Óssea , Proteínas Morfogenéticas Ósseas/uso terapêutico , Bovinos , Tomografia Computadorizada de Feixe Cônico , Feminino , Humanos , Masculino , Teste de Materiais , Dente Serotino/cirurgia , Reprodutibilidade dos Testes , Fatores de Tempo , Extração Dentária/métodos , Alvéolo Dental/transplante , Dente Impactado/cirurgia , Resultado do Tratamento , Adulto JovemRESUMO
Abstract It is necessary to preserve height and thickness of the alveolar bone to facilitate rehabilitation with osteointegratable implants or simply to maintain bone integrity after extraction. Biomaterials associated with resorbable or non-resorbable membranes, when placed in the region of the socket, may contribute to avoid this unwanted reabsorption. Objective The objective of this study was to evaluate the distance of the crest of alveolar ridge to the cementoenamel junction (CEJ) of the lower second molars and the bone density of the third molar socket filled with Gen-Tech®, 5 years after an exodontia using cone beam computed tomography (CBCT) to visualize the central region of the sockets, without overlapping of the buccal and lingual cortical bones. Material and Methods A total of 12 individuals from an initial group of 39 patients submitted to extraction of the unruptured lower third molars and grafting of an association of inorganic bovine bone matrix, organic bovine bone matrix, collagen and bone morphogenetic proteins (BMP) (Gen-Tech®) on one side and the contralateral sockets filled only by clot, returned to control after 5 years, and were submitted to CBCT. The distance from the crest of alveolar bone to the CEJ and the bone density (BD) were measured using the i-CAT Vision Software. Results The results showed that the distance from the crest of alveolar bone to the CEJ in the control group was similar to that observed before the exodontia; in the experimental group, this distance was smaller. Considering the BD measurement, a significantly higher density was observed in the experimental group (p<0.05). Conclusion Part of the biomaterial was not absorbed and allowed the stability of the evaluated parameters after 5 years, being able to be used as a bone substitute in the socket.
Assuntos
Humanos , Animais , Masculino , Feminino , Adolescente , Adulto , Bovinos , Adulto Jovem , Dente Impactado/diagnóstico por imagem , Transplante Ósseo/métodos , Substitutos Ósseos , Colo do Dente/diagnóstico por imagem , Alvéolo Dental/diagnóstico por imagem , Xenoenxertos/diagnóstico por imagem , Dente Serotino/diagnóstico por imagem , Fatores de Tempo , Extração Dentária/métodos , Dente Impactado/cirurgia , Teste de Materiais , Densidade Óssea , Reprodutibilidade dos Testes , Resultado do Tratamento , Proteínas Morfogenéticas Ósseas/uso terapêutico , Alvéolo Dental/transplante , Tomografia Computadorizada de Feixe Cônico , Dente Serotino/cirurgiaRESUMO
Pancreatic adenocarcinoma is important in oncology because of its high mortality rate. Deaths may be avoided if an early diagnosis could be achieved. Several types of tumors overexpress gastrin-releasing peptide receptors (GRPr), including pancreatic cancer cells. Thus, a radiolabeled peptide derivative of gastrin-releasing peptide (GRP) may be useful as a specific imaging probe. The purpose of the present study was to evaluate the feasibility of using (99m)Tc-HYNIC-ßAla-Bombesin(7-14)as an imaging probe for Capan-1 pancreatic adenocarcinoma. Xenographic pancreatic tumor was developed in nude mice and characterized by histopathological analysis. Biodistribution studies and scintigraphic images were carried out in tumor-bearing nude mice. The two methods showed higher uptake by pancreatic tumor when compared to muscle (used as control), and the tumor-to-muscle ratio indicated that (99m)Tc-HYNIC-ßAla-Bombesin (7-14)uptake was four-fold higher in tumor cells than in other tissues. Scintigraphic images also showed a clear signal at the tumor site. The present data indicate that (99m)Tc-HYNIC-ßAla-Bombesin (7-14) may be useful for the detection of pancreatic adenocarcinoma.
Assuntos
Adenocarcinoma/diagnóstico por imagem , Bombesina/análogos & derivados , Compostos de Organotecnécio/farmacocinética , Neoplasias Pancreáticas/diagnóstico por imagem , Adenocarcinoma/patologia , Animais , Bombesina/farmacocinética , Linhagem Celular Tumoral , Peptídeo Liberador de Gastrina/análogos & derivados , Xenoenxertos/diagnóstico por imagem , Xenoenxertos/patologia , Humanos , Masculino , Camundongos Nus , Músculos/diagnóstico por imagem , Neoplasias Pancreáticas/patologia , Fragmentos de Peptídeos/farmacocinética , CintilografiaRESUMO
The objective of this study was to determine the ability of bone morphogenetic protein (BMP) and fibroblast growth factor (FGF) to repair large segmental radial bone defects in rabbits. We treated calf cancellous bones with 3 mg/L BMP (Group A), 5 µg/L FGF (Group B), or 3 mg/L BMP plus 5 µg/L FGF (Group C). A bone damage model was established using healthy radii from rabbits. The complexes were implanted in the areas of the bone defects in the radii. After successful transplantation, the rabbits underwent radiographic imaging, and bone graft specimens were detected by histopathology methods. Biomechanical indexes were also assessed in order to observe the healing status of the bone defects. Our results indicated that the repair of bone defects was significantly better in Group C compared to the other 2 groups. Therefore, we concluded that combining BMP and FGF significantly promoted bone defect repair and achieved effects that were superior to the use of BMP alone.
Assuntos
Proteínas Morfogenéticas Ósseas/administração & dosagem , Regeneração Óssea/efeitos dos fármacos , Transplante Ósseo , Fatores de Crescimento de Fibroblastos/administração & dosagem , Animais , Desenvolvimento Ósseo/efeitos dos fármacos , Regeneração Óssea/genética , Bovinos , Fêmur/diagnóstico por imagem , Fêmur/efeitos dos fármacos , Fêmur/crescimento & desenvolvimento , Xenoenxertos/diagnóstico por imagem , Xenoenxertos/efeitos dos fármacos , Coelhos , Radiografia , Cicatrização/efeitos dos fármacosRESUMO
PURPOSE: The aim of this study was to analyze histologically and radiographically the influence of particle size of anorganic bovine bone matrix (ABBM) on bone repair. MATERIALS AND METHODS: Four calvarial defects of 8 mm each were prepared in 18 adult New Zealand rabbits. The defects were then filled with either particulate autogenous bone (control group) or ABBM of large, medium, and small size granules. The animals were sacrificed at 15, 30, and 60 days after surgery. The samples were radiographically examined before being submitted to histological processing. RESULTS: Autogenous bone showed a slight radiopacity at the beginning, which was increased at the final period, being very similar to the adjacent bone tissue. The large and medium size ABBM particles maintained the same radiographic behavior, showing a radiolucent area in the central portion of the defect at 60 days. ABBM of small size granules showed a slight radiolucity at the initial period, which was increased at the subsequent periods. More intense bone formation occurred in the control group (autogenous bone). All 3 particle sizes of the biomaterial resulted in inflammatory infiltration at 15 and 30 days. ABBM of small size granules lead to a greater amount of osteoid tissue, and the particles were almost totally reabsorbed within 60 days of implantation. CONCLUSIONS: Autogenous bone graft lead to the best result in terms of bone defect repair; ABBM of large and medium size granules are not totally reabsorbed at the observed period; ABBM of small size granules was more intensively reabsorbed and led to a greater osteoid tissue formation when compared to the medium and large ABBM granules.