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Piezocision is a new periodontal method for cutting bone more precisely than conventional methods, such as bur drilling, with 3D ultrasonic vibration power. We have conducted a study on piezocision effect on periodontal tissue in rodents. Our previous animal studies demonstrated that piezocision hastens tooth movement in rodents compared to conventional methods. The histological results showed that piezocision induces bone resorption and regeneration quickly. In addition, we observed the same effect of piezocision surgery on clinical tooth movement in collaboration with the orthodontists at BUSDM. We believe that piezocision can contribute significantly to dental therapies. However, more studies of piezocision effects are necessary for a thorough understanding. Periodontal tissue healing requires the participation of regulatory molecules, cells, and scaffold or matrix. We hypothesized that piezosurgery induces alveolar bone regeneration by uncovered procedures. In this study, we focused on the cells contributing to synthesis or repair of periodontal tissue, such as osteocytes, osteoclasts, osteoblasts, white blood cells, and periodontal ligament cells in order to close the gap between clinical knowledge and cellular mechanisms Histological analysis and MRI data indicates that piezocision surgery enhanced alveolar bone degradation in the post-operative early phase (from day1 to day7), and induced bone regeneration in the post-operative mid phase (from day14 to day28). The structure of alveolar bone was similar to controls in the late phase (day70). Serum ALP activity, a bone formation marker, was significantly increased by Piezocision surgery (p<0.05). Piezocision increasd serum CTX, a bone degradation biomarker, at post-operative 7day in the 30Hz Piezocision surgery (p<0.05). In addition, Serum PINP, a bone formation biomarker, was significantly decreased in the post-operative early phase. TUNEL assays revealed that osteocyte apoptosis was induced in alveolar bone by piezocision at post-operative 1day. Apoptosis in osteocytes induces osteoclast activity that leads to bone degradation. In previous studies piezocision induced TRAP activity in the post-operative early phase. Runx2 positive osteoblast progenitor cells were observed in the post-operative day7 and 14 as assessed by Immunofluorescence microscopy analysis. The Runx2 positive cells accumulated near the new bone formation area. The structure of collagen was observed by histological staining with Pico Sirius Red. Piezocision resulted in deteriorated collagen structure in the post-operative early phase that recovered in the post-operative mid phase. Since the collagen fibers filled in the gap between alveolar bone and roots, we stained the sections with Periostin, a specific PDL biomarker. Periostin was observed on the collagen fibers that filled in the gap between bone and root. previous studies revealed that the expression of Periostin induced TGF beta, a pivotal molecule for osteoblast differentiation. Taken together, these studies indicate that periodontal tissue responds to Piezosurgery by alveolar bone decalcification and regeneration. Further elucidation of the role of the each conducting cells (eg. osteocytes, osteoclast, osteoblast, periodontal ligament cells) after piezosurgery in the periodontal tissue may provide a new target for the treatment of periodontal disease by stimulating the return to tissue homeostasis.

Made available in DSpace on 2014-06-11T19:33:28Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-06-06Bitstream added on 2014-06-13T19:23:26Z : No. of bitstreams: 1 ruiz_kgs_dr_arafo.pdf: 357284 bytes, checksum: 93541a495590ca3b701f6cf9ef876131 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo do presente estudo foi avaliar o efeito da combinação do fator de crescimento de fibroblastos básico (b-FGF) e fator de transformação de crescimento beta (TGF- beta) na proliferação, expressão de genes para colágeno tipos I e III, metaloproteases -1 e -2 e TIMPs 1, 2 e 3, e na síntese destes próprios fatores de crescimento pelas células do ligamento periodontal de humanos. A avaliação da proliferação celular foi realizada após os períodos de 24 e 48h na presença dos fatores de crescimento, através da mensuração do nível de MTS reduzido a formazan pelas células viáveis, e a síntese de b-FGF e TGF-b pelo teste ELISA empregando a técnica sandwich. Conclui-se que as associações do bFGF e do TGF-b atuaram de maneira dose-dependente no estímulo à proliferação celular, o aumento na expressão de genes para colágeno e TIMPs e redução para as metalproteases e modulação da síntese deles próprios. / The aim of this study was to evaluate the effect of association of basic fibroblast growth factor and transforming growth factor beta on the proliferation, expression of colagen type I e III, matrix metalloproteinases-1 e -2 e TIMPs 1, 2 e 3, and on the modulation of the syntheses oh these growth factors by humans periodontal ligament cells. The cellular proliferation was evaluated to 24 and 48 hours of incubation by the colorimetric method. The synthese of bFGF and TGF-ß was verificated by ELISA method, using a sandwich techinique, and mRNA expression by Real Time - PCR. In conlusion, the associations of bFGF e TGF-ß influenced of dose-dependent manner on the cellular proliferation, on the increasing of the expression to collagen and TIMPs, and on the reduction to metaloproteinases and, the modulation of these own synthesis.

Orientador: Ricardo Samih Georges Abi Rached / Banca: Silvana Regina Perez Orrico / Banca: Regina Maria Barretto Cicarelli / Banca: Francisco Humberto Nociti Junior / Banca: Márcio Zafallon Casati / Resumo: O objetivo do presente estudo foi avaliar o efeito da combinação do fator de crescimento de fibroblastos básico (b-FGF) e fator de transformação de crescimento beta (TGF- beta) na proliferação, expressão de genes para colágeno tipos I e III, metaloproteases -1 e -2 e TIMPs 1, 2 e 3, e na síntese destes próprios fatores de crescimento pelas células do ligamento periodontal de humanos. A avaliação da proliferação celular foi realizada após os períodos de 24 e 48h na presença dos fatores de crescimento, através da mensuração do nível de MTS reduzido a formazan pelas células viáveis, e a síntese de b-FGF e TGF-b pelo teste ELISA empregando a técnica "sandwich". Conclui-se que as associações do bFGF e do TGF-b atuaram de maneira dose-dependente no estímulo à proliferação celular, o aumento na expressão de genes para colágeno e TIMPs e redução para as metalproteases e modulação da síntese deles próprios. / Abstract: The aim of this study was to evaluate the effect of association of basic fibroblast growth factor and transforming growth factor beta on the proliferation, expression of colagen type I e III, matrix metalloproteinases-1 e -2 e TIMPs 1, 2 e 3, and on the modulation of the syntheses oh these growth factors by humans periodontal ligament cells. The cellular proliferation was evaluated to 24 and 48 hours of incubation by the colorimetric method. The synthese of bFGF and TGF-ß was verificated by ELISA method, using a "sandwich" techinique, and mRNA expression by Real Time - PCR. In conlusion, the associations of bFGF e TGF-ß influenced of dose-dependent manner on the cellular proliferation, on the increasing of the expression to collagen and TIMPs, and on the reduction to metaloproteinases and, the modulation of these own synthesis. / Doutor