Effect of recombinant human bone morphogenetic protein 2 associated with a variety of bone substitutes on vertical guided bone regeneration in rabbit calvarium.

BACKGROUND: A major challenge for dental implantology is to consistently obtain appropriate bone augmentation before implant placement. The aim of this study is to evaluate the effect of recombinant human bone morphogenetic protein 2 (rhBMP-2) associated with bone substitute materials beta-tricalcium phosphate (ß-TCP), biphasic calcium phosphate (BCP), and bovine bone mineral on vertical guided bone regeneration (GBR) in rabbit calvarium. METHODS: Four titanium cylinders were fixed to the calvarium of 22 rabbits. In group 1 (n = 10), three cylinders were randomly filled with one of the test materials, and one cylinder was filled with a blood clot (CL). In group 2 (n = 12), the cylinders were randomly assigned to the same materials and CL but with the addition of rhBMP-2. Bone labels were injected over the course of 13 weeks, and euthanasia was performed 14 weeks after surgery in both groups. RESULTS: The mean volume and area of tissue growth was greater in group 2 (with rhBMP-2) than in group 1 (without rhBMP-2), irrespective of the material used (P <0.001). The mean volume of tissue growth in the CL cylinder was smaller than that observed with all other materials (P <0.001) in both groups. The mean area of regenerated bone in the CL cylinder was smaller than that observed in the ß-TCP cylinder (P = 0.028). The histologic study revealed more lamellar bone in the rhBMP-2 group, with a greater level of biodegradation of all the bone substitute materials tested. CONCLUSION: The use of rhBMP-2/absorbable collagen sponge (ACS) combined with all of the bone substitute materials tested resulted in a greater amount of bone formation than that produced with the bone substitute materials alone or rhBMP-2/(ACS) and CL using the rabbit calvarium GBR model.

Homoenxertos ósseos: a captação e o processamento geram segurança para a utilização? / Bone allografts: Does the collecting and processing method generate security for its use?

Frente à popularização das reabilitações bucais com próteses sobre implantes e da ausência, por vezes, de suficiente ou adequado tecido ósseo, a demanda dos enxertos ósseos tem aumentado progressivamente. Nas situações de extenso déficit ósseo ou frente à necessidade de reduzir o tempo e a morbidade cirúrgica, o uso de homoenxertos ósseos deve ser considerado, já que são encontrados em quantidades ilimitadas nos bancos de tecidos. No entanto, a possibilidade da transmissão de doenças infecciosas é uma constante preocupação dos profissionais e dos pacientes envolvidos. O presente trabalho tem como objetivo, por intermédio de uma revisão de literatura — realizada manualmente e através da base de dados Medline, compreendendo o período de 1990 a 2010 —, verificar a segurança oferecida pela captação e pelo processamento dos homoenxertos ósseos. Pode-se concluir que as etapas do processamento como a liofilização, a desmineralização e a irradiação gama geram níveis de segurança confiáveis e que, associados a uma prévia seleção de doadores e captação dos homoenxertos criteriosas, reduzem a possibilidade de infecção, assim gerando segurança.

The popularization of oral rehabilitation with prostheses on implants increased the demand of bone grafts. The use of bone allografts should be considered in situations of extensive bone deficit or when facing the reduction of time and surgical morbidity, since they are available in unlimited amounts in tissue banks. However, the possibility of infectious diseases' transmission is a common concern by the professionals and the involved patients. This paper aims to verify the security of collecting and processing bone allografts through a literature review that was performed manually covering Medline database from 1990 to 2010. It can be concluded that the processing steps such as freeze drying, demineralization and gamma radiation are reliable and in association with a judicious donor selection and collection of bone allograft performed previously, reduce the chance of infection, thereby creating safety.