Injeção de agregados plaquetários no rejuvenescimento facial: uma revisão sistemática / Injection of platelet aggregates in facial rejuvenation: a systematic review

Introdução: Essa revisão sistemática foi conduzida para avaliar se a associação da aplicação da injeção de agregados plaquetários quando comparada a outras terapias faciais favorece no rejuvenescimento facial em pacientes adultos. Métodos: A pesquisa buscou ensaios clínicos randomizados que compararam uso de técnicas de rejuvenescimento facial isoladas com as mesmas técnicas aliadas à injeção de agregados plaquetários. A busca foi realizada em bases de dados indexadas e literatura cinzenta. A ferramenta de risco de viés da "Cochrane Collaboration" foi aplicada para a avaliação da qualidade dos estudos. Resultados: Foram identificados 7137 artigos. Apenas quatro estudos permaneceram na síntese qualitativa, e os demais foram considerados com risco indefinido de viés nos domínios chaves. Conclusão: Existem poucos estudos na literatura que comparam o uso de agregados plaquetários em rejuvenescimento facial e os que estão disponíveis têm risco de viés "indefinido" ou "alto". Há necessidade de realizar mais estudos clínicos bem delineados que comparem o uso de injeção de agregados plaquetários associados ou não às técnicas de rejuvenescimento facial.

Introduction: This systematic review was conducted to assess whether the use of a platelet aggregate injection with or without associated facial rejuvenation techniques favors facial rejuvenation in adult patients. Methods: Randomized clinical trials that compared the use of techniques for facial rejuvenation alone with the same techniques coupled with the injection of platelet aggregates were searched. The search was performed in indexed databases and in the gray literature. The Cochrane Collaboration bias risk tool was applied to assess the quality of the studies. Results: In total, 7137 articles were identified. Only four studies remained in the qualitative synthesis, and the others were considered as having undefined bias risk in the key domains. Conclusion: There are few studies in the literature that compare the use of platelet aggregates in facial rejuvenation and those that are available have a risk of "undefined" or "high" bias. There is a need for more well-designed clinical studies comparing the use of platelet aggregate injection with or without associated facial rejuvenation techniques.

Immunoexpression of BMP-2 protein on bone repair of critical size defects treated with autogenous macerated adipose tissue

Introduction: The adipose tissue is an important reservoir of adult stem cells which have capacity of differentiating in osteoblasts with potential implication in reaching bone regeneration. The evaluation of the osteoblastic differentiation can be verified through immunohistochemical markers such as bone morphogenetic protein- 2 (BMP-2). Objective: To evaluate the immunoexpression of BMP-2 protein on the bone repairing of critical size defects (CSD) surgically created in rat calvaria and treated by autogenous macerated adipose tissue. Material and methods: Forty male rats had a CSD measuring 5 mm created on their calvaria. The animals were randomly divided into two groups: group C (control) and group AT (macerated adipose tissue grafting). In group C, the defect was filled with only blood clot. In group AT, the defect was filled with autogenous macerated adipose tissue. The groups were subdivided into two subgroups (n = 10) for euthanasia at 7 and 90 post-operative days. Histological and immunohistochemical analyses were carried out. Data were submitted to descriptive statistics (mode). Results: In group AT, both at 7 and 90 post-operative days, the main healing type was the presence of dense conjunctive tissue exhibiting bundles of collagen fibers disposed in beams permeating the remaining adipose tissue with rare heterotopic bone formation associated to fibrosis and different types of tissue necrosis. In group C, the repair was achieved by the formation of bundles of collagen fibers oriented parallelly to the surface of the wound at the two post-surgical periods. The immune-staining of BMP-2 was present only in group C (7 and 90 post-operative days). Conclusion: Within the limits of this present study, it can be concluded that the adipose tissue grafting did not favor bone neoformation in critical size defects and BMP-2 signaling was not observed.

Analysis of tensile strength of poly(lactic-coglycolic acid) (PLGA) membranes used for guided tissue regeneration

Introduction: The challenge of restoring patient's function that presented some loss of an organ or tissue encourages the Tissue Engineering and Biotechnology to develop materials that promote bone regeneration. Poly(lactic-co-glycolic acid) (PLGA) copolymer is among of the most biomaterials used. Objective: To evaluate the tensile strength of PLGA membranes at different conditions of humidity and temperature. Material and methods: PLGA membranes were hourglass-shape cut and prepared at three different conditions of temperature and humidity (n = 10): (I) dry membrane at environment temperature of about 20ºC (control group), (II) moist membrane plasticized at 55ºC, (III) moist membrane plasticized at 55ºC, which subsequently underwent cooling. Subsequently, the membranes were subjected to tensile tests in a universal testing machine (DL-2000, EMIC) at 1.0 mm/min. Data was submitted to ANOVA and Tukey's test (p < 0.05). Results: Group I showed the highest tensile strength mean (16.7 ± 1.9a MPa, p = 0.0022). There was no statistically significant difference between the means of groups II (14.6 ± 1.4 MPab) and III (13.9 ± 1.7 MPab). Conclusion: The dried PLGA membranes showed higher tensile strength than the membranes that were only either plasticized or cooled.

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.