Uso do hormônio do crescimento associado à fibrina rica em plaquetas e leucócitos injetável (I-PRF) / Use of the growth hormone associated with injectable platelet-rich fibrin (I-PRF)

Objetivo: demonstrar, por meio de uma revisão de literatura, a utilização do hormônio do crescimento (GH) e concentrados plaquetários e sugerir técnica de associação de uso para odontologia em processos de preservação de osso alveolar. Revisão de literatura: enxertos ósseos são uma necessidade na área da saúde, por diversas razões. A utilização de osso autógeno apresenta grande desvantagem em ter um segundo sítio cirúrgico, entretanto, os substitutos ósseos não possuem as características ideais. Assim, existe a busca por alternativas que otimizem a cicatrização e a incorporação dos substitutos ósseos, dentre elas os concentrados sanguíneos, ricos em fatores de crescimento derivados das plaquetas e o hormônio do crescimento. É possível encontrar uma vasta literatura utilizando os concentrados sanguíneos, inclusive utilizando esses como veículos para outras substâncias. Os concentrados sanguíneos são ricos em fatores de crescimento derivados das plaquetas, como fator de crescimento semelhante à insulina (IGF), Fator de crescimento derivado de plaquetas (PDGF) e outros. Além disso, também é possível encontrar, na literatura, o uso tópico de hormônio do crescimento em enxertos ósseos, fraturas e implantes dentários. Entretanto, o GH possui uma meia-vida de 20 minutos, assim, quando utilizado em conjunto com a I-PRF, espera-se um aumento no tempo de ação local. Considerações finais: é possível otimizar os enxertos ósseos utilizando-se L-PRF/I-PRF e hormônio do crescimento. Porém, são necessárias mais pesquisas.(AU)

Objective: this study aims to show through a literature review the use of the growth hormone and platelet concentrates and to suggest an association technique for dentistry use in alveolar bone preservation processes. Literature review: bone grafts are a health requirement for a number of reasons. The use of autogenous bone has the main disadvantage of a second surgical site, while bone substitutes do not present optimal characteristics. Thus, there is a search for alternatives that optimize the healing and incorporation of bone substitutes, which include blood concentrates that are rich in platelet-derived growth factors and the growth hormone. A vast literature can be found on blood concentrates, including their use as vehicles to other substances. Blood concentrates are rich in platelet-derived growth factors such as IGF, PDGF, and others. Moreover, the literature also shows the topical use of the growth hormone in bone grafts, fractures, and dental implants. However, the growth hormone presents a half-life of 20 minutes; therefore, when combined with I-PRF, an increased time in local action is expected. Final considerations: it is possible to optimize bone grafts by using L-PRF/I-PRF and the growth hormone. However, further research is required.(AU)

Update on operative treatment of scapholunate (SL) instability for radiologists: part 1-SL ligament repair, dorsal capsulodesis and SL ligament reconstruction.

Scapholunate instability is the most common form of carpal instability. Imaging (especially radiography) plays an important role in the staging, management and post-operative follow-up of scapholunate (SL) instability. The goals of this article are to review the pre-operative staging of SL instability, the surgical options for repair and reconstruction of the SL ligament, along with the normal postoperative imaging findings as well as complications associated with these surgical options.

In vivo tissue engineered bone versus autologous bone: stability and structure.

This pilot study investigated the biomechanical properties of prefabricated, vascularized bioartificial bone grafts, which may provide an alternative bone source for the restoration of segmental osseous defects. Vascularized bioartificial bone grafts comprise an artificial customized scaffold made of beta-tricalcium phosphate. Bone formation along the prefabricated scaffold is induced by autogenous cancellous bone. Vascularization of the bone graft is provided by the host's vascular system. Within 6 months, a mammalian bioreactor (sheep were used in the present study) creates heterotopic vascularized bioartificial bone grafts of a predetermined anatomical shape, which can be harvested for reconstructing osseous defects. The bioartificial bone grafts in this study contained up to 25% bone tissue, as shown by histomorphometric analysis and computed tomography. Moreover, unconfined compression tests revealed that the constructs had mechanical characteristics similar to those of ovine cancellous bone. Therefore, this method could be applied to generate vascularized prefabricated bone substitutes for critical-size defects.

En bloc prefabrication of vascularized bioartificial bone grafts in sheep and complete workflow for custom-made transplants.

The aim of this pilot study was to determine, in a new experimental model, whether complex bioartificial monoblocs of relevant size and stability can be prefabricated in a defined three-dimensional design, in which the latissimus dorsi muscle serves as a natural bioreactor and the thoracodorsal vessel tree is prepared for axial construct perfusion. Eighteen sheep were included in the study, with six animals in each of three experimental groups. Vitalization of the ß-tricalcium phosphate-based constructs was performed by direct application of unmodified osteogenic material from the iliac crest (group A), in vivo application of nucleated cell concentrate (NCC) from bone marrow aspirate (group B), and in vitro cultivation of bone marrow stromal cells (BMSC) in a perfusion bioreactor system (group C). The contours of the constructs were designed digitally and transferred onto the bioartificial bone grafts using a titanium cage, which was bent over a stereolithographic model of the defined subvolume intraoperatively. At the end of the prefabrication process, only the axial vascularized constructs of group A demonstrated vital bone formation with considerable stability. In groups B and C, the applied techniques were not able to induce ectopic bone formation. The presented computer-assisted workflow allows the prefabrication of custom-made bioartificial transplants.

Reconstrução de maxila atrófica com uso de enxerto ósseo homólogo particulado com macro e micropartículas antes da colocação de implantes dentários / Reconstruction of the atrophic maxillary arch with homologous macro and microparticulate homologous bone grafts before dental implant placement: a case report

Este relato de caso descreve uma nova técnica de reconstrução para o rebordo maxilar atrófico antes da colocação de implantes dentários. Enxertos homólogos consistindo de macro e micropartículas foram injetados sem o uso de membranas. Após 11 meses, o tecido gengival demonstrou aspecto saudável e ganho em espessura no rebordo alveolar. Os exames por imagem também demonstraram ganho em altura. Esta técnica é uma alternativa clínica viável e menos traumática em relação às outras técnicas para o aumento ósseo em maxilas atróficas

This case report describes a new technique to reconstruct the atrophic maxillary arch before dental implant placement. Macro and microparticulate homologous grafts were injected without membrane insertion. After 11 months, the gingival tissue displayed normal condition along with improved alveolar bone thickness. Also, the CBCT images demonstrated benefits in bone height. This is a viable clinical alternative and less traumatic than other surgical modalities for bone grafting in the atrophic maxilla.