Clinical Similarities and Histological Diversity Comparing Fresh Frozen Onlay Bone Blocks Allografts and Autografts in Human Maxillary Reconstruction

Abstract

Human fresh-frozen bone block AL showed clinical compatibility for grafting procedures, although associated to slow remodeling process. Further studies are needed to define, at long term, the remodeling process chronology the clinical longitudinal results for fresh-frozen bone AL.

Bone grafting and osseointegration in the area of maxillary tooth agenesis. Case report

“…After the six-month histomorphometric evaluation between in-block allogeneic and autogenous bone graft, limited amount (8%) of viable allogeneic bone were found, consisting of conjunctive tissue and non-vital bone; while autogenous blocks showed approximately three times more vital bone (28%) [14,15]. Recently, other histomorphometric analysis [15,16] agreed with previous results evidencing the best integration and remodeling of the autogenous bone over other allogeneic bone types.…”

“…Differently from previous studies [15,16], a new histological and histomorphometric evaluation of autogenous bone graft [14], between three and nine months, indicate signs of active remodeling. However, the grafted bone had substantial amounts of non-vital bone and little neovascularization, regardless of the time.…”

“…The bone remodeling after allogeneic graft occurs by means of newly-formed bone and blood vessels spread through the grafted material [14]. This regenerative and remodeling process of in-block grafts is influenced by many factors, as allogeneic bone origin, surgical technique, bone volume available before the surgery, healing time, and different receptor sites [17].…”

“…However, the grafted bone had substantial amounts of non-vital bone and little neovascularization, regardless of the time. The authors suggested that most part of the osteocytes of the monocortical bone did not survive the grafting and the neovascularization, which explained by the slow remodeling [14].…”

Substitutos Ósseos Alógenos E Xenógenos Comparados Ao Enxerto Autógeno: Reações Biológicas

“…Por outro lado, embora a utilização dos mesmos tenha mostrado resultados clínicos satisfatórios até o momento, faltam informações sobre a composição [Misch 1987] -Implante -M e s m a e s p é c i e , indivíduos diferentes [Sobreira 2011] -Implante -Espécies diferentes [Sobreira 2011] PROPRIEDADES -Osteocondutor -Osteoindutor -Osteogênico (Buser 2010) -Osteocondutor [Lutz 2015] -Osteocondutor [Lutz 2015] REAÇÕES IMUNOLOGICAS "NÃO" -Contém células do próprio hospedeiro, não transmite doenças infeciosas ou desencadeia reações imunológicas [Bauer 2000] "SIM" -Resposta imune pode ser desencadeada por componentes do tecido ósseo [Graham 2010] -Lacunas contendo osteócitos [Spin-Neto 2013B] -Remanescentes, células mortas [Van de Vord 2005] -Sensibilização Imunológica [Lacerda et al, 2016Piaia et al, 2017 "NÃO" -Protocolo de tratamento rigoroso de acordo com AATB diminuiu riscos [Waasdorp 2010] "SIM" -Príon BSE [Kim 2013] -Remanescentes Orgânicos [Tapety 2004] -Agentes patogênicos ou material genético [Pruss 2002] "NÃO" -Não é reconhecido como corpo estranho [Tapety 2004] -Após 11 e 14 anos em íntimo contato com o osso [Ayna 2015 e Mordenfeld 2010] VANTAGENS -Rápidas incorporação e consolidação (Burchardt 1987) -Não transmite doenças infecciosas [Bauer 2000] - …”