Avaliação clínica, tomográfica, microtomográfica e histológica da reconstrução alveolar horizontal com uso de enxerto heterógeno em bloco
Carregando...
Data
2020-08-27
Autores
Carvalho, Pedro Henrique de Azambuja
Título da Revista
ISSN da Revista
Título de Volume
Editor
Universidade Estadual Paulista (Unesp)
Resumo
Este trabalho teve por objetivo avaliar o comportamento do osso bovino desproteinizado em bloco (DBBM), na reconstrução horizontal de maxila atrófica, em comparação com bloco de osso autógeno do ramo mandibular (AB). As etapas e resultados estão aqui apresentadas na forma de quatro artigos científicos, o primeiro uma revisão sistemática acerca do uso de enxertos ósseos heterógenos para aumento horizontal de rebordo, o segundo e o terceiro com resultados do ensaio clínico randomizado em humanos, e o quarto a avaliação morfológica e laboratorial do material testado. Foram selecionados 12 pacientes com edentulismo total da maxila, sem comprometimento sistêmico, maiores de 18 anos e rebordo remanescente com espessura mínima de 2mm e altura mínima de 10 mm, excluídos os fumantes, irradiados ou em tratamento com medicações que alteram o metabolismo ósseo. As reconstruções ósseas horizontais foram realizadas com DBBM ou AB, aleatoriamente distribuídos em modelo de boca dividida. Tomografias de feixe cônico e medidas transoperatórias da espessura do rebordo foram realizadas em três momentos: inicial (T0), imediatamente após a enxertia óssea (T1) e prévio a instalação de implantes (T2). Após nove meses, os pacientes foram submetidos a reabertura dos sítios enxertados para a instalação de implantes, nos quais foram aferidos os valores do torque de inserção e coeficiente de estabilidade inicial (ISQ), biópsias foram obtidas das áreas enxertadas para avaliação histológica e microtomográfica. Para análise laboratorial as amostras foram submetidas a avaliação ex-vivo e de potencial pro-inflamatório em cultura celular de osteoblastos humanos. A instalação de implantes foi possível em todos os sítios enxertados, 5 pacientes apresentaram uma ou mais complicações no leito receptor (AB:3; DBBM:2), sendo as principais: deiscência da ferida e exposição de membrana e/ou enxerto. O ganho de volume não foi diferente entre os grupos, mas a reabsorção média em porcentagem foi menor no grupo AB: (10.83% ± 8.23 vs. 16.73% ± 8,01). O torque de instalação e ISQ não apresentaram diferença estatística entre os grupos. Nos parâmetros microtomográficos, a superfície óssea foi menor no grupo AB: (12,01 ± 2,16 vs. 14.69 ± 2,66) enquanto a espessura de trabécula foi maior (0.5 ± 0.33mm vs. 0.28 ± 0.04mm), A quantidade de tecido mineralizado foi maior no grupo AB, mas não houve diferença para a área de tecido mole e de osso vital nos cortes histológicos. Na análise ex-vivo foram identificados remanescentes orgânicos e celulares, no entanto o DBBM testado não alterou a expressão de citocinas pró infamatórias dos osteoblastos in-vitro. Como conclusão, no presente estudo os enxertos de osso bovino em bloco apresentaram comportamento clínico, tomográfico e histológico semelhante ao osso autógeno para os parâmetros avaliados, além de não estimular a expressão de citocinas pró-inflamatórias em osteoblastos.
The aim of this work was to evaluate the features involving the use of deproteinized bovine bone matrix DBBM in maxillary horizontal ridge augmentation. The phases and results of this work are presented in four full papers. The first one is a systematic review about the use of xenogenous grafts in horizontal ridge augmentation. The second and third presented the results of a randomized clinical trial comparing DBBM block with block of autogenous bone from mandibular ramus (AB). And the fourth evaluates the morphologic and in vitro behavior of the tested material Twelve adult patients with edentulous atrophic maxillary ridges and without systemic health diseases were random selected in a list of patients for oral rehabilitation with implants. Irradiated patients, patients with systemically diseases and post menopause women were excluded. The patients were submitted to reconstructive surgery under general anesthesia. Each side of anterior maxilla received one type of graft, according to randomization, DBBM or AB. Cone bean Computerized Tomography (CBCT) scans and trans-operatory thickness assessment were performed at three times: initial (T0), immediate post-operative (T1) and nine months after surgery (T2). Nine months later an all-on-four protocol was installed, and it was measured implant torque and implant stability quotient (ISQ). Also, biopsies were obtained from grafted areas for microtomographic and histological evaluation. DBBM block and granules were submitted to ex-vivo morphologic analysis and in-vitro inflammatory induction in primary human osteoblasts(pOB). All the 24 grafted areas were able to implant placement, 5 patients presented one or more complications, (AB: 3, DBBM: 2). The main complications were wound dehiscence and graft exposure. The volumetric changes were not statically different between groups, but the mean resorption was lower in AB group (10.83% ± 8.23 vs 16.73% ± 8,01). Installation torque and ISQ presented no statistical difference. In the microtomographic parameters the specific bone surface was lower in the AB: (12,01 ± 2,16 vs. 14.69 ± 2,66), while the trabecula was thicker in AB (0.5 ± 0.33mm vs. 0.28 ± 0.04mm). The mineralized tissue area was grater in AB, but no differences were observed between soft tissue and vital bone at the evaluated histologic slides. In the ex-vivo analysis cellular and organic remnants were found in DBBM blocks, but the tested material did not upregulate the pro-inflammatory cytokines in pOB. In the current study the low temperature sintered OBDB presented as an alternative for maxillary horizontal augmentation, with clinical, tomographic and histological behavior similar to AB, and have not induced pro-inflammatory response in vitro.
The aim of this work was to evaluate the features involving the use of deproteinized bovine bone matrix DBBM in maxillary horizontal ridge augmentation. The phases and results of this work are presented in four full papers. The first one is a systematic review about the use of xenogenous grafts in horizontal ridge augmentation. The second and third presented the results of a randomized clinical trial comparing DBBM block with block of autogenous bone from mandibular ramus (AB). And the fourth evaluates the morphologic and in vitro behavior of the tested material Twelve adult patients with edentulous atrophic maxillary ridges and without systemic health diseases were random selected in a list of patients for oral rehabilitation with implants. Irradiated patients, patients with systemically diseases and post menopause women were excluded. The patients were submitted to reconstructive surgery under general anesthesia. Each side of anterior maxilla received one type of graft, according to randomization, DBBM or AB. Cone bean Computerized Tomography (CBCT) scans and trans-operatory thickness assessment were performed at three times: initial (T0), immediate post-operative (T1) and nine months after surgery (T2). Nine months later an all-on-four protocol was installed, and it was measured implant torque and implant stability quotient (ISQ). Also, biopsies were obtained from grafted areas for microtomographic and histological evaluation. DBBM block and granules were submitted to ex-vivo morphologic analysis and in-vitro inflammatory induction in primary human osteoblasts(pOB). All the 24 grafted areas were able to implant placement, 5 patients presented one or more complications, (AB: 3, DBBM: 2). The main complications were wound dehiscence and graft exposure. The volumetric changes were not statically different between groups, but the mean resorption was lower in AB group (10.83% ± 8.23 vs 16.73% ± 8,01). Installation torque and ISQ presented no statistical difference. In the microtomographic parameters the specific bone surface was lower in the AB: (12,01 ± 2,16 vs. 14.69 ± 2,66), while the trabecula was thicker in AB (0.5 ± 0.33mm vs. 0.28 ± 0.04mm). The mineralized tissue area was grater in AB, but no differences were observed between soft tissue and vital bone at the evaluated histologic slides. In the ex-vivo analysis cellular and organic remnants were found in DBBM blocks, but the tested material did not upregulate the pro-inflammatory cytokines in pOB. In the current study the low temperature sintered OBDB presented as an alternative for maxillary horizontal augmentation, with clinical, tomographic and histological behavior similar to AB, and have not induced pro-inflammatory response in vitro.
Descrição
Palavras-chave
Aumento do rebordo alveolar, Xenoenxertos, Substitutos ósseos, Ensaio clínico controlado aleatório, Alveolar ridge augmentation, Xenografts, Bone substitute materials, Randomized controlled trial