Growth hormone effects on healing efficacy, bone resorption and renal morphology of rats: histological and histometric study in rat calvaria.

Previous reports demonstrated the utility of systemic application of growth hormone (GH) in the treatment of bone defects. Very few studies correlated bone repair efficacy with hepatic and renal side effects promoted by locally-delivered GH. The objectives of this study were to assess the bone repair properties along with hepatic and renal adverse effects promoted by local application of GH in a rat model. Thirty-two rats were randomly divided (4 groups; n = 8/group), as follows: (i) AB (autogenous bone + local application of saline solution [SS]), (ii) AB+ (autogenous bone + SS local application + SS irrigation), (iii) AB/GH+ (autogenous bone + SS local application + GH irrigation) and (iv) AB/GHL+ (autogenous bone + GH local application + GH irrigation). Critical-sized defects (diameter = 5.0 mm) were surgically created by a single operator in the calvaria of rats. Defects were filled with ground autogenous bone. Defects pertaining to AB+ and AB/GH+ received a mixture of autogenous bone and a SS-saturated (0.02 mL) collagen sponge covered with bovine cortical membrane. Defects in group AB/GHL+, were filled with the same biomaterials saturated with GH (0.02 mL). SS (0.1 mL) or GH (0.1 mL, equivalent to 0.4 IU) were applied locally on alternate days (8 weeks) in animals in groups AB, AB+ and AB/GH+ or AB/GHL+, respectively. Bone repair properties was determined in hematoxylin/eosin-stained slices using traditional histologic and histomorphometric techniques along with optical microscopy and digital image analysis. Statistical differences among groups was determined using Kruskal-Wallis and Tukey post hoc tests (α = 0.05). Histology results indicated that AB and AB+ displayed greater presence of autogenous bone as compared to AB/GH+ and AB/GHL+. Histomorphometric results indicated significantly higher osteoid matrix formation in AB and AB+ when compared to AB/GHL+ (p = 0.009). Kidneys and livers were found to have their glomeruli preserved in AB and AB+. Strong glomeruli necrosis and large areas of protein deposition were found in AB/GH+. Abnormal small-sized glomeruli were found in AB/GHL+. The utilization of autogenous bone graft associated with local application and irrigation with GH was shown to not improve the bone repair in calvarial critical-sized defects in a rat model.

Alendronate disturbs femoral growth due to changes during immunolocalization of transforming growth factor-ß1 and bone morphogenetic protein-2 in epiphyseal plate.

BACKGROUND: The epiphyseal growth plate is an important anatomical segment localized on the ends of a long bone. Despite the abovementioned atractive reasons for alendronate's use, few data on the effect of alendronate during epiphyseal growth exist. AIM: Verify the effect of alendronate on the growth epiphyseal plate, and compare its effect with the size of the femur during the double-staining of the immunolocalization of transforming growth factor-ß1 (TGF-ß1) and bone morphogenetic protein-2 (BMP2) in endochondral ossifing in specimens that have received alendronate. METHODS: Forty newborn rats were randomly divided into two groups: a control group (were given applications of 1 mg/kg physiologic saline) and a group that received Alendronate (a dose of 2.5 mg/kg). These groups were then divided into two subgroups for euthanasia in two and 12 d of life. After euthanasia, the femurs were removed, and the femoral bones were measured linearly between the apex of the greater trochanter until the lower intercondylar midlle face to verify the probable bone growth between 3 and 12 d in control and alednroanto treated rats. Posteriorly, the surgical pieces were also sent to the histopathology laboratory to produce histological slides. The obtained slides were stained with hematoxylin and eosin to measure each of the cartilage zones in endochondral development. and other slides were immunohistochemically tested for anti- TGF-ß1 and BMP-2 antibodies to investigate the immunolocalization of these proteins in the epiphyseal plaque area. RESULTS: On the third day, some diferences between the control group and specimens treated with alendronate were verified. Macroscopiccaly, we found similarities in size between the femoral bones when we compared the control group with the specimens that received alendronate. On the 12th day, the bone size of the mice receiving the drug was significantly smaller than those of the control group. These results coincide with changes in the TGF-ß1 and BMP-2 expression. In the specimens that received alendronate, the TGF-ß1 was expressed in some sites of trabecular bone that was neoformed, peripherally to the bone marrow area. The BMP-2 was also positive in proliferative chondrocytes and hypertrofic chondrocytes. On the 12th day, all layers of chondrocytes exhibited positivity for BMP-2 in the specimens that received alendronate. In the interface between the trabecular bone and cartilage, an area of disorganized bone deposition was evident. Neoformed bone also appeared to be different at 12 d. In the control group, BMP-2 was positive in an intense area of bone trabeculae, whereas the alendronate-treated group showed TGF-ß1 positive trabeculae and a greater bone area. CONCLUSION: Alendronate alters the immunolocalization of TGF-ß1 and BMP-2 simultaneously, a condition that changes the usual histological aspects of the cartilage zone and impairs epiphysis growth and femur growth.

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.

Bone repair in craniofacial defects treated with different doses of alendronate: a histological, histomorphometric, and immunohistochemical study.

OBJECTIVE: The objective of the study is to evaluate bone repair in rats treated with different alendronate doses. MATHERIALS AND METHODS: Sixty female rats ovariectomized were randomly divided in three groups: group C (control group), group A1 (ALN/1 mg/kg), and A2 (ALN/ 3 mg/kg). Each animal received subcutaneous applications of sodium alendronate at a dose correspondent to group A1 or A2 three times a week, while the control group received 0.9% saline solution. After 4 weeks of application, a critical defect was created in the calvaria of animals of all groups. The defect was filled by particulate autogenous bone. The applications were maintained until euthanasia, which occurred 15 and 60 days after the surgical procedure. The pieces were sent for histological, histomorphometric and immunohistochemical analysis. The data were submitted to statistical analysis with significance level of 0.05. RESULTS: The descriptive histological analysis demonstrated an increase in bone neoformation in both groups treated with alendronate when compared to the control group. The histomorphometric analysis showed an increase in the amount of neoformed bone in A1 and A2 groups when compared to group C, both at 15 days (p = 0.0002) and at 60 days (p = 0.001). In the immunohistochemical analysis, it was possible to observe a difference in immunolabeling just for Mmp2 at the time of 60 days in A1 (p = 0.001) and A2 (p = 0.023) when compared to the control group. CONCLUSION: Systemic delivery of alendronate, regardless of the dose, increased the amount of bone neoformation. CLINICAL RELEVANCE: Prescription of sodium alendronate at 1 mg/kg for improvement of bone neoformation in bone graft procedures.

Percepção do estudante sobre a implantação do método OSCE no curso de Odontologia em uma universidade particular / Student's perception of the implementation of the OSCE method in the Dentistry course of a private university

O Objective Structured Clinical Examination (OSCE) é uma avaliação que observa e intervém nas inseguranças dos estudantes em uma condição clínica simulada. Essa forma de avaliar competências, habilidades clínicas, conhecimento, atitudes, comunicação e profissionalismo é considerada uma ferramenta importante no processo de ensino-aprendizagem. Nesse contexto, surgiu a necessidade em implementar, no curso de Odontologia, a avaliação de competência clínica OSCE. O objetivo do estudo foi avaliar a percepção do estudante de Odontologia sobre o método OSCE e seu impacto na formação acadêmica deles. Participaram 34 estudantes do último ano do curso. O instrumento de coleta de dados foi um questionário com opções de respostas ("discordo", "concordo", "concordo parcialmente", "indiferente") que foi respondido voluntariamente. Os dados foram submetidos ao teste Qui-quadrado que comparou as respostas das quatro aplicações da metodologia OSCE durante o ano, com nível de significância de 95% (p<0,05). Em relação à mesma pergunta, a diferença também foi significativa na última avaliação (93,1%; p=0,017). Quanto ao método ter contribuído para o futuro na prática profissional, 93,1% (p=0,042) dos estudantes concordaram, na última avaliação do ano. Pode-se concluir, com base na análise de resposta dos questionários nos quatro bimestres, que a percepção dos estudantes de Odontologia do 5á´¼ ano noturno da Universidade Positivo frente à introdução do método OSCE foi bem aceita e positiva, uma vez que a maioria das respostas indicaram que o método contribuiu significativamente para a formação e ofereceu oportunidade de aprendizagem (AU).

The Objective Structured Clinical Examination (OSCE) is used to detect and intervene in the students' lack of confidence in a simulated clinical condition. The OSCE assesses competences, clinical skills, knowledge, attitude, communication, and professionalism, being considered an important tool in the teachinglearning process. This context raised the need to implement the OSCE clinical competence assessment. The objective of the study was to assess the dentistry student's perception of the OSCE method and its impact on their academic training. This study included thirty-four sênior students. The data were collected using a multiple-choice questionnaire ("disagree", "agree", "partially agree", "indifferent") voluntarily answered. The chi-square test was used to analyze the data by comparing the answers of four OSCE methodology applications during the year, with a 95% (p <0.05) significance level. The difference was also significant regarding the same question in the last assessment (93.1%, p = 0.017). As for the method having contributed to their future professional practice, 93.1% (p = 0.042) of the students agreed in the last assessment of the year. Based on the analysis of questionnaire answers in the four bimesters, we concluded that the perception of the students attending the 5th year of dentistry at Positivo University is that the implementation of the OSCE method was well accepted and positive, since most of the answers indicated that the method significantly contributed to their training and provided learning opportunities (AU).

Evaluating surfaces of titanium dental implants after contact with surgical gloves, steel rongeur, and titanium tweezers using scanning electron microscopy

Introduction and Objective: To use scanning electron microscopy (SEM) and determine whether the surfaces of titanium implants are damaged when touched with a steel rongeur, titanium tweezers, or surgical gloves. Material and methods: Ten dental implants were divided into five groups: Control (C), Titanium Tweezers (T-T), Steel Rongeurs (S-R), Surgical Gloves (S-G), and Steel Support (S-S). The implants were assembled in a metallic base (stub) with the aid of copper strips. They were then imaged and their microstructures were characterized using SEM. Results: An analysis of the obtained images showed that the implants that had been handled with titanium tweezers or a steel rongeur suffered some damage to their physical structure; "scratches" and other small signs of damage were visible on their surfaces. The affected areas were very small compared to the total surface area of the implants. Small dark local stains were observed at the spots where some of the implants had rubbed against a steel support. The rubbing of the implants against the support did not cause any structural damage. The implants handled with surgical gloves exhibited many dark stains their surfaces. This suggested that the powder from the surgical gloves had contaminated the surfaces of the implants. Conclusion: Using SEM imaging, it was determined that the surfaces of dental implants suffer minor physical damage when handled with various pieces of dental equipment. However, the damage should not result in failure of the osseointegration process. In vivo studies are needed to confirm this hypothesis.