Microbial evaluation of implant surface - a clinical study comparing submerged, non-submerged and immediately loaded implants

Aim: The aim of the present study was to evaluate the microbial contamination in internal and external walls of cone morse implant walls. Methods: Eleven patients with edentulous mandibular posterior area were selected to received dental implants, divided into groups: submerged (S), non-submerged (NS), and immediately loaded (IL). Microbiological evaluations (microorganisms' number, aerobic and anaerobic colony forming units (CFU) number and microorganisms' qualification) were divided into internal and external collection of the implant walls, at different stages: T0 (surgical procedure), T2 (suture removal), T4 (reopening S group), T6 (suture removal S group), and T8 (abutment placement in S and NS). All data were submitted to statistical analyses, with confidence level of 0.05. Results: There was difference in number of microorganisms observed over time within the same group (p < 0.05). A difference was observed in CFU when evaluated within the same group over time (p < 0.05), except for the IL group. In internal collection, a predominance of non-formation of microorganisms was observed at T0 in all groups, while formation of Gram-positive Diplococci and Gram-positive Bacilli was observed at T8 (p>0.05). In external collection, an increase in number of microorganisms was observed at T0. Conclusion: There was no difference in microbial contamination among the evaluated groups. The microorganism's colonization changed over time

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.

Genetic polymorphism in ESR2 and risk of tooth agenesis

Introduction: Tooth agenesis (TA) is the congenital absence of teeth. Several studies have proposed a strong genetic background for this condition. Aim: The present cross-sectional study aimed to evaluate whether genetic polymorphisms in the genes that code for estrogen receptors ( ESR1 and ESR2 ) are associated with the presence of isolated TA in a Brazilian sample. Methods: Panoramic radiographs of 142 orthodontic patients were assessed to determine TA of permanent teeth (excluding third molars). DNA of patients was extracted from buccal cells from saliva to evaluate genetic polymorphisms in ESR1 ( rs2234693 and rs9340799 ) and ESR2 ( rs1256049 and rs4986938 ) by genotyping using the real-time PCR technique. For statistical analyses, associations between the distributions of the alleles and genotypes, and the ocurrence of TA were assessed for each genetic polymorphism, with an established alpha of 5%. Results: Thirteen patients had at least 1 congenital missing tooth. The number of congenitally missing teeth ranged from 1 to 11. The genetic polymorphisms rs2234693 and rs9340799 in ESR1 and rs1256049 in ESR2 were not associated with TA ( p > 0.05) . For the genetic polymorphism rs4986938 in ESR2, the genotype and allele distributions were significantly different between the patients with and without TA ( p < 0.05). The CC genotype and the C allele were overrepresented in the TA patients. Conclusion: The genetic polymorphism rs4986938 in ESR2 was associated with the ocurrence o f TA.

Introdução: A agenesia dentária (AD) é a ausência congênita de um ou mais dentes. Vários estudos vêm sugerindo o forte componente genético para essa condição. Objetivo: O presente estudo teve como objetivo avaliar se os polimorfismos genéticos nos genes que codificam os receptores de estrógeno ( ESR1 e ESR2 ) estão associados à ocorrrência de AD isolada em uma amostra brasileira. Métodos: Radiografias panorâmicas de 142 pacientes ortodônticos foram avaliadas para determinar AD de dentes permanentes (excluindo terceiros molares). O DNA dos pacientes foi extraído das células da mucosa bucal contidas na saliva para avaliar polimorfismos genéticos em ESR1 ( rs2234693 e rs9340799 ) e ESR2 ( rs1256049 e rs4986938 ) por genotipagem usando a técnica de PCR em tempo real. Para análises estatísticas, associações entre as distribuições dos alelos e genótipos e a ocorrrência de AD foram avaliadas para cada polimorfismo genético, com um alfa estabelecido de 5%. Resultados: Treze pacientes tiveram pelo menos 1 dente congenitamente ausente. O número de dentes congenitamente ausentes variou de 1 a 11. Os polimorfismos genéticos rs2234693 e rs9340799 no ESR1 e rs1256049 no ESR2 não foram associados à AD ( p > 0,05). Para o polimorfismo genético rs4986938 no ESR2 , as distribuições dos genótipos e dos alelos foram estatisticamente diferentes entre os pacientes com e sem AD ( p < 0,05). O genótipo CC e o alelo C estavam super-representados nos pacientes com AD. Conclusão: Houve associação entre o polimorfismo genético rs4986938 no ESR2 e a ocorrrência de AD.

Effect of local application of alendronate and parathyroid hormone on craniofacial bone repair - a preliminary study

Abstract This study aimed to evaluate the effect of two methods of local application of alendronate and parathyroid hormone (PTH) on bone repair and the systemic implications. A critically sized defect (5 mm) was created in the cranial region of twenty-five male Wistar rats, and the bone removed was particulated, and grafted back to the defect with different treatments. The animals were randomly divided into five groups: A1- bone graft immersion in alendronate solution (3 mg/kg) for 5 minutes; P1- bone graft immersion in PTH solution (20 µg); A2- weekly local applications of alendronate 1 mg/kg; P2- weekly local applications of PTH (20 µg); C- no drugs were used. The animals were euthanized 60 days after surgery. Cranial bone blocks were removed for histological, histomorphometric, and immunohistochemical analyses. MMP-2 and MMP-9 were used for immunolabeling. The kidneys, liver, and brain were also removed from all the rats for histological analysis. The data were submitted for statistical analysis with a level of significance of 0.05 (One-way ANOVA). The group C and group P2 presented a higher quantity of viable bone particles than the remaining groups. Groups A1, A2, and P1 presented with fewer viable bone particles than the control group, with a predominance of non-mineralized connective tissue. The histomorphometric analysis revealed no differences in relative bone area or MMP-2 or MMP-9 immunolabeling between the groups (p>0.05). Group A2 showed presence of fat in the liver consistent with hepatic steatosis. Changes in brain tissue were observed in groups A1 and P1.

Resumo Este estudo visou avaliar o efeito de dois métodos de aplicação local de alendronato e de paratormônio (PTH) no reparo ósseo e avaliar as implicações sistêmicas. Um defeito de tamanho crítico (5 mm) foi criado na calota craniana de vinte e cinco ratos Wistar machos, e o osso removido foi particulado e enxertado de volta no defeito com diferentes tratamentos. Os animais foram divididos aleatoriamente em cinco grupos: A1: imersão do enxerto ósseo em solução de alendronato (3 mg/kg) durante 5 min; P1- imersão do osso em solução de PTH (20 μg); A2- aplicações locais semanais de alendronato 1 mg/kg; P2- aplicações locais semanais de PTH 20 μg; C: não foram utilizados medicamentos. Os animais foram eutanasiados 60 dias após a cirurgia. Foram removidos os blocos ósseos envolvendo a região do defeito para realização das análises histológica, histomorfométrica e imuno-histoquímica. MMP2 e MMP9 foram as imunomarcações utilizadas. Os rins, fígado e cérebro também foram removidos de todos os ratos para análise histológica. Os dados foram submetidos à análise estatística com um nível de significância de 0,05 (One-way ANOVA). A análise histológica revelou que o grupo C e o grupo P2 apresentaram maior quantidade de partículas ósseas viáveis do que as apresentadas pelos demais grupos. Os grupos A1, A2 e P1 apresentaram menos partículas ósseas viáveis em comparação com o grupo controle com predominância de tecido conjuntivo não mineralizado. A análise histomorfométrica não revelou diferenças entres os grupos na área óssea relativa ou em MMP2 e MMP9 (p>0,05). O grupo A2 mostrou presença de gordura no fígado consistente com esteatose hepática. Alterações no tecido cerebral foram observadas nos grupos A1 e P1.

Oral and masticatory rehabilitation using osseointegrated dental implants after resective treatment of multicystic ameloblastoma in the lower jaw with a fibula graft

Ameloblastoma is an aggressive odontogenic tumor which typically occurs between third and fourth decade of life that often needs resective approach. Immediate reconstruction may show better results. The treatment of multicystic ameloblastoma in the mandible being a rare case that occurred in the late second decade of life, which was surgically removed along with the affected teeth with safety margins, and the region was immediately reconstructed using a vascularized graft, removed from the fibula. Its integration, in combination with osseointegrated dental implants and fixed implant-supported prostheses, restored chewing function and esthetics. After 6 years from fibular graft and 24 months of dental implants, an excellent outcome was observed, with oral health and normal functions properly restored, and the immediate reconstruction of the mandible in resective cases, associated with oral rehabilitation with dental implants, may be considered a suitable treatment option.

Saúde bucal e periodontal podem ser afetadas após cirurgia bariátrica e deficiências nutricionais? / an oral and periodontal health may be affected after bariatric surgery and nutritional deficiencies?

Objetivo: tentar entender como as deficiências nutricionais no paciente pós-operatório à cirurgia bariátrica impactam a saúde oral e periodontal. Material e métodos: uma pesquisa na base de dados PubMed com os termos "by-pass gástrico e doenças periodontais", "cirurgia bariátrica e deficiências nutricionais", e "saúde bucal e obesidade" tentando esclarecer a relação com doença periodontal e as deficiências nutricionais. Resultados: foi realizada uma revisão de artigos sobre o fato da cirurgia bariátrica ser um procedimento cirúrgico indicado para o tratamento da obesidade mórbida e promover alteração da anatomia gastrintestinal, levando à perda de peso, diminuindo a absorção de açúcares, gorduras e outros nutrientes importantes, como vitaminas A, C, D, B12, cálcio e ferro, responsáveis pela regulação de muitas funções críticas no organismo e participantes efetivos na produção de colágeno e matriz óssea. Conclusão: a cavidade oral sofre complicações em vista dessa nova situação, e os dentistas precisam entender como essas deficiências podem afetar na doença periodontal, a fim de desenvolver estratégias de prevenção e tratamento para este novo grupo de população.

Objective: the aim of this article is try to understand how the nutritional deficiencies in the post-operative patient submitted to bariatric surgery impact on oral and periodontal health. Material and methods: a survey in PubMed database with these terms "gastric by-pass and periodontal diseases", "bariatric surgery and nutritional deficiencies" and "oral health and obesity" was done trying to clarify the relationship with periodontal disease. Results: bariatric surgery is a surgical procedure indicated for the treatment of morbid obesity and promotes an alteration of gastrointestinal anatomy leading to a marked weight loss by decreasing the absorption of sugars and fats, but other important nutrients such as decreased absorption of vitamins A, C, D, B12, calcium and iron, which are also responsible for the regulation of many critical functions in organism, and effectively participate in the production of collagen and bone matrix and an overview of papers about this topic was conducted. Conclusion: the oral cavity suffers complications from this new situation and dentists need to understand how these deficiencies may impact on periodontal disease in order to develop treatment and prevention strategies for this new population group.

Effect of the use of different periodontal curettes on the topography and roughness of root surface

Introduction: Periodontal scaling is the treatment approach most used to remove dental calculus, plaque, and altered cementum from root surface. During root decontamination, the instruments used leave the root rougher and more irregular. Objective: To verify the root surface after mechanical scaling with different Gracey curettes steel through SEM and superficial roughness analyses. Material and methods: Twelve teeth were embedded in acrylic resin. The teeth were instrumented with new Gracey curettes Gracey 5/6 from different brands. The groups (n=2) were divided into: control, no instrumentation (GC); carbon steel (CSN); stainless steel Neumar (SSN); stainless steel Millenium (SSM); premium steel Neumar (PSN); Hu-Friedy (HF). An area measuring 3 x 3 mm2 was marked on the distal surface of the root to guide the Reading of the root topography on SEM and rugosimeter. The data were analyzed by a single examiner previously calibrated. SEM analysis was based on scores of the root surface smoothness after scaling. We analyzed the parameters of mean roughness (Ra) and mean roughness deepness (Rz). SEM data were submitted to statistical analysis through Fisher's exact test (p < 0.002) and roughness data by Anova followed by Student t test. Results: The quality of the active surface of the curette demonstrated by SEM and roughness analyses that it can exert difference in the result regarding to the homogeneity produced after the scaling of root surface. Group SSM demonstrated a homogenous root surface (score 0) in SEM and better smoothness in rugosimeter analysis. Conclusion: According to com the methodology used, the group of curettes that provided better smoothness of root surface after scaling was SSM.

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.

Investigation of the influence of design details on short implant biomechanics using colorimetric photoelastic analysis: a pilot study

Introduction : The clinical survival of a dental implant is directly related to its biomechanical behavior. Since short implants present lower bone/implant contact area, their design may be more critical to stress distribution to surrounding tissues. Photoelastic analysis is a biomechanical method that uses either simple qualitative results or complex calculations for the acquisition of quantitative data. In order to simplify data acquisition, we performed a pilot study to demonstrate the investigation of biomechanics via correlation of the findings of colorimetric photoelastic analysis (stress transition areas; STAs) of design details between two types of short dental implants under axial loads. Methods Implants were embedded in a soft photoelastic resin and axially loaded with 10 and 20 N of force. Implant design features were correlated with the STAs (mm2) of the colored fringes of colorimetric photoelastic analysis. Results Under a 10 N load, the surface area of the implants was directly related to STA, whereas under a 20 N load, the surface area and thread height were inversely related to STA. Conclusion A smaller external thread height seemed to improve the biomechanical performance of the short implants investigated.

Non-Pedicled Buccal Fat Pad Grafts to Treatment for Class I and II Gingival Recessions: A Clinical Trial

The aim of this study was to analyze the transplant efficiency of non-pedicled buccal fat pad graft (BFPG) for the treatment of Miller Class I or II gingival recessions (GRs) and to compare these results with those of subepithelial connective tissue graft (SCTG), which is considered the gold standard. Twelve patients with Miller Class I or II (≥2 mm) bilateral recessions in maxillary premolars or canines were selected. Recessions were randomly assigned to receive SCTG or BFPG. The clinical parameters evaluated at baseline and at 1, 3, and 6 months postoperatively included gingival index, plaque index, probing depth, GR, clinical attachment level, width of keratinized tissue, thickness of keratinized tissue and gingival margin to the acrylic guide. None of the evaluated clinical parameters differed significantly between the groups. At all evaluated postoperative time-points, both groups exhibited statistically significant differences in GR and gingival margin to the acrylic guide compared to baseline. Six months after surgery, the mean percentages of root coverage were 67.5% and 87.5% in the BFPG and SCTG groups respectively. In both groups, complete root coverage was observed in 50% of cases 6 months after surgery. The results presented herein indicate that the use of BFPG transplant has clinical similarities with SCTG and both may be considered as clinically successful methods for treating Miller Class I and II GRs.

Resumo O objetivo deste estudo foi analisar a eficiência do transplante do enxerto de tecido adiposo bucal não pediculado (ETAB) para o tratamento de recessões gengivais Classe I e II de Miller e comparar seus resultados com o enxerto de tecido conjuntivo (ETC), que é considerado o enxerto padrão ouro. Foram selecionados 12 pacientes com recessões gengivais bilaterais Classe I e II de Miller presentes em canino ou pré-molares maxilares. As recessões foram randomizadas para receber um dos dois tratamentos ETAB ou ETC. Os parâmetros clínicos avaliados no baseline e com 1, 3 e 6 meses de pós-operatório foram o índice gengival, índice de placa, profundidade de sondagem, recessão gengival (RG), nível clinico de inserção, espessura e largura de tecido queratinizado e a medida da margem gengival ao guia de acrílico (MG-GA). Os resultados mostraram que não houve diferença estatisticamente significativa entre os grupos em nenhum dos parâmetros clínicos avaliados. Os parâmetros clínicos de RG e MG-GA, em ambos os grupos, apresentaram diferença estatisticamente significativa nos 3 períodos pós-operatórios em relação ao baseline. Aos 6 meses de pós-operatório, a média percentual de recobrimento radicular foi de 67,5% e 87,5% para o grupo ETAB e ETC respectivamente. Em ambos os grupos o recobrimento radicular completo foi em 50% dos casos após 6 meses de pós-operatório. Pode-se concluir que o transplante do ETAB apresentou similaridades clínicas com o ETC e ambos os tratamentos podem ser considerados de sucesso clínico para o tratamento de RGs Classe I e II de Miller.

Determination of final occlusal vertical dimension by cephalometric analysis

Introduction: Most of techniques for determining the occlusal vertical dimension (OVD) of edentulous patients are based on soft tissues references, which lead to measurement discrepancies. Objective: To propose a method to obtain the OVD of edentulous patients during the confection of complete dentures considering the lower facial height established by Ricketts (LFHr) or the lower facial height obtained from cephalometric analysis of dentulous patients (LFHd). Material and methods: The OVD of 11 edentulous patients was determined by the association of 3 clinical methods. On each patient's bite plates a metallic ball was fixed and the patient was submitted to lateral radiographic to obtain the lower facial height (LFHe) from cephalometric analysis. Additionally, from 40 lateral cephalograms of dentulous patients the LFHd was obtained. After that, the distance between metallic balls (DMB, in mm) was calculated to verify the linear difference when LFHe was changed to LFHd or LFHr, which provided the amount of wax to be added or removed from the bite plates, establishing a new method of OVD determination. LFHe, LFHd and LFHr values were submitted to t e z statistical tests and DMB differences were analyzed by Student's t-test (α=0.05). Results: LFHr (47.0±4.0o a) was statistically higher than LFHd (44.9±5.6o b) and LFHe (43.5±3.5o b). There was statistical difference on linear discrepancies calculated between the LFHe and LFHd (1.7±4.1mm a) or LFHr (4.2±4.1mm b). Conclusion: The use of the cephalometric analysis showed to be a useful auxiliary tool in determining the intermaxillary relationship. However, this method must be associated with different clinical methods of OVD determination and it is recommended that regional references are used to calculate the linear discrepancies.

Influence of bisphosphonates on Implantology - literature review

Introduction: Oral rehabilitation with dental implants becomes limited in patients who make use of sodium bisphosphonate (BF), because this drug inhibits osteoclast activity and thus osteoblastic, fundamental steps to implant osseointegration. Furthermore, this drug can cause osteonecrosis of the jaw (OJ). The dentist has to fully know about this drug and its side effects, to differentiate it from other changes. Objective: This study aimed to review the literature on the influence of bisphosphonates on implant and to evaluate the possible complications resulting from prolonged use, providing subsidies to the dentist to prevent and recognize the patient with osteonecrosis of the jaws Literature review: The BPs are a class of drugs used for the treatment of bone diseases such as osteoporosis, because their mechanism of action inhibits the function of osteoclast. However, these drugs may cause some side effects known as the OJ. Patients undergoing intravenous therapy are more likely to develop these changes than those undergoing oral therapy. OJ is characterized by painful symptoms, leaving the exposed bone in the oral cavity. There are several treatment strategies according to the clinical stage that the patient presents. Conclusion: The installation of dental implants in patients who make use of BPs presents risks, since this drug can cause OJ.

Platelet-leukocyte-rich plasma (L-PRP) prevents the collagen III degradation and impairs the bone matrix development in artificial defect of rabbit calvaria, associated with suppression of the immunohistochemical expression of MMP-2 and MMP-9

Introduction and Objective: Because L-PRP constitutes an important source of growth factor that is associated with osteogenesis and fibrogenesis, the aim of this study was to evaluate the effect of L-PRP on the presence of collagen III and MMP-2 and MMP-9, while comparing these results by means of a histomorphometric analysis of bone matrix and fibrous deposition on bone repair. Material and methods: Four bone defects of 8 × 2 mm were created on the calvaria of 21 rabbits. The surgical defects were treated with either particulate autograft, particulate autograft mixed with L-PRP, or L-PRP alone. Animals were euthanized at 2, 4, and 6 weeks postoperative. Histomorphometric and immunohistochemical analyses were performed to assess repair time, as well as the expression of collagen III and MMPs. Results: In contrast to the results of the L-PRP-free groups, the histomorphometric results of the L-PRP groups demonstrated intense fibrotic deposition along with hindered bone matrix deposition. These results coincided with the larger occurrence of diffuse collagen III deposition and the scarce presence of MMP- 2 and -9 spread among the fibrous tissue. Conclusion: Thus, the results suggest that L-PRP not only induces an intense fibrosis rich in collagen III, which is not degraded, but also suppresses MMP-2 and -9 expressions, mimicking a similar pathological event as that of a cleft-palate or cranial suture.

Correlation Between Radiographic Area and Immunolocation of MMP-2 and MMP-9 in Unilocular Radiographic Lesions

Unilocular bone cysts are the most common entities affecting the maxillofacial region. The mechanism of proliferation and expansion remains unclear. Metalloproteinases (MMPs) are associated to diverse pathological conditions. The aim of the present study was to correlate the radiographic aspect (area) and the presence of MMP-2 and MMP-9 in dentigerous cysts, radicular cysts and keratocystic odontogenic tumors. The radiographic area of each lesion was calculated using the mathematical formula of the ellipse area. All specimens were subjected to immunohistochemical analysis for these enzymes. The average radiographic area was 284.17 mm2, 235.81 mm2 and 381.81 mm2, respectively. Statistical analyses revealed no association between the immunoreactivity of MMPs and radiographic area of the lesions in all pathologies studied, except for MMP-2 and radicular cysts, for which smaller lesions had increased immunostaining for this enzyme. The results demonstrate that quantities of MMP-2 and MMP-9 are especially involved with dentigerous and radicular cysts in expansion, whereas these enzymes seem to be related to the biological behavior of keratocystic odontogenic tumors, indicating invasion and cell proliferation. Moreover, there is an inverse association between MMP-2 and MMP-9 in keratocystic odontogenic tumors (p=0.03; rs=-0.660), indicating activity in different regions.

Cistos ósseos uniloculares são as entidades mais comuns que afetam a região maxilofacial. O mecanismo de proliferação e expansão permanece obscuro. As metaloproteinases (MMPs) estão associadas a diversas condições patológicas. O objetivo do presente estudo foi correlacionar o aspecto radiográfico (área) e a presença de MMP-2 e MMP-9 em cistos dentígeros, cistos radiculares e tumores odontogênicos queratocísticos. A área radiográfica de cada lesão foi calculada usando a fórmula matemática da área de elipse. Todas as amostras foram submetidas à análise imunoistoquímica para estas enzimas. A área radiográfica média foi de 284,17 mm2, 235,81 mm2 e 381,81 mm2, respectivamente. As análises estatísticas não mostraram associação entre a imunorreatividade de MMPs e área radiográfica das lesões em todas as patologias estudadas, exceto para MMP-2 e cistos radiculares, nas quais as lesões menores tinham maior imunomarcação para esta enzima. Os resultados demonstraram que a quantidade de imunomarcação da MMP-2 e MMP-9 estão envolvidos com cistos dentígeros e radiculares na expansão óssea, ao passo que estas enzimas parecem estar relacionados com o comportamento biológico dos tumores odontogénicos queratocísticos, indicando invasão e proliferação celular. Além disso, há uma relação inversa entre a MMP-2 e MMP-9 em tumores odontogénicos queratocísticos (p=0,03; rs= -0,660), indicando atividade em diferentes regiões.

Uso da cola cianoacrílica para estabilização de enxerto gengival livre / Cyanoacrylate surgical glue for free gingival graft immobilization

Introdução: a recessão gengival é definida como a mi-gração apical da margem da gengiva tendo como conse-quências a exposição radicular e a redução da faixa de gengiva inserida. O enxerto gengival livre (EGL) é uma opção de tratamento para esses casos. A estabilização do enxerto na área receptora pode influenciar o resul-tado final do procedimento. Objetivo: o presente relato de caso tem como objetivo demonstrar que o EGL pode ser fixado na região cirúrgica com o uso da cola cirúr-gica N-butyl 2-cyanoacrylate (Glubran-2), substituindo as suturas convencionais, no tratamento de regiões des-providas de gengiva inserida. Relato de caso: a investi-gação, neste estudo, se deu em uma paciente do sexo feminino de 22 anos com recessão gengival classe I de Miller no dente 41 com um defeito de 5 mm na vestibu-lar, bem como ausência de gengiva inserida. O EGL foi posicionado sobre a linha mucogengival formando um leito receptor e uma gota da cola Glubran-2 foi coloca-da em cada extremidade do enxerto para estabilização. Considerações finais: com base nos dados observados, conclui-se que a cola cirúrgica N-butyl 2-cyanoacrylate (Glubran-2) pode ser considerada como substituta ao uso de suturas convencionais.

Immunoexpression of PPAR-? and Osteocalcin Proteins for Bone Repair of Critical-Size Defects Treated with Fragmented Autogenous Abdominal Adipose Tissue Graft

Immunoexpression of PPAR-γ and osteocalcin proteins was evaluated for bone repair of critical-size defects (CSDs), created in rat calvaria (n=42) and treated with fragmented abdominal autogenous adipose tissue graft. Three groups (n=14) were formed: C (control - blood clot), AB (autogenous bone) and AT (fragmented adipose tissue). The groups were divided into subgroups (n=7) for euthanasia at 30 and 90 days. Histological and immunohistochemical analyses were performed. Data were subjected to descriptive statistics (mode). A complete bone closure was observed in Group AB 90 days after surgery. In Group C, repair was achieved by the formation of collagen fiber bundles oriented parallel to the wound surface at both post-surgery periods. In Group AT the type of healing was characterized by dense connective tissue containing collagen fiber bundles arranged amidst the remaining adipose tissue, with rare heterotopic bone formation associated with fibrosis and different types of tissue necrosis. Immunostaining of PPAR-γ was not observed in any specimen from Groups C and AB. In Group AT, the immunostaining of PPAR-γ was more evident 30 days after surgery. Immunostaining of osteocalcin was present in all groups and at both postoperative periods. The fragmented autogenous abdominal adipose tissue graft did not favor the repair of critical-size bone defects created surgically in rat calvaria as evidenced by the positive immunostaining of PPAR-γ protein and the negative immunostaining of osteocalcin in the osteoblast-like cells and bone matrix.

A imunoexpressão das proteínas PPAR-γ e osteocalcina foi avaliada para o reparo ósseo de defeitos de tamanho crítico (DTC) criados em calvária de ratos (n = 42) e tratados com enxerto de tecido adiposo autógeno abdominal macerado. Foram formados três grupos (n=14): C (controlo - coágulo de sangue), AB (osso autógeno) e AT (tecido adiposo fragmentado). Estes grupos foram divididos em subgrupos (n = 7) para a eutanásia em 30 e 90 dias. Foram realizadas análises histológicas e imuno-histoquímico. Os dados foram submetidos à análise estatística descritiva (moda). Um fechamento ósseo completo foi observada no grupo AB 90 dias após a cirurgia. No grupo C a reparação foi alcançada através da formação de feixes de fibras de colágeno orientadas paralelamente à superfície da ferida nos dois períodos pós-operatórios. No Grupo AT, o tipo de cicatrização predominante foi caracterizada pela presença de tecido conjuntivo denso contendo feixes de colágeno de fibras dispostas em meio ao tecido adiposo restante, com raras formações ósseas heterotópicas associada à fibrose e diferentes tipos de necrose tecidual. A imunomarcação do PPAR- γ não foi observada em nenhum espécime dos grupos C e AB. No grupo AT a imunomarcação do PPAR-γ foi mais evidente aos 30 dias de pós-operátorio. A imunomarcação da osteocalcina estava presente em todos os grupos e nos dois períodos de pós-operatório O enxerto autógeno abdominal fragmentado tecido adiposo não favoreceu a reparação de defeitos ósseos de tamanho crítico criados cirurgicamente em calvária de ratos como evidenciado pela imunomarcação positiva da proteína PPAR-γ e a imunomarcação negativa de osteocalcina nos osteoblastos e matriz óssea.

Clinical setting influences physiological responses in dental implant patients

AIM: To evaluate changes in blood pressure and heart rate in patients undergoing dental implant procedures, considering the dental setting as the main variable. METHODS: Fifty-five patients who underwent dental implant surgery were evaluated. Thirty-seven were treated at a university clinic and 18 were treated at a private office. Blood pressure and heart rate were measured at the following time-points: at the appointment prior to surgery (T0), immediately before the surgical procedure (T1), during anesthesia (T2), during implant installation (T3), immediately after the surgical procedure (T4) and at the first follow-up appointment after surgery (T5). The data were analyzed by two-way analysis of variance and Student's t-test. RESULTS : The university clinic patients had an increase in heart rate at T5 (t53=2.62, p<0.05) compared with private office patients. Systolic blood pressure in university clinic patients was higher at T2 (t53=2.86, p<0.01), T3 (t53=2.64, p<0.05), and T4 (t53=3.15, p<0.01). Diastolic blood pressure at T2 (t53=3.15, p<0.01) and T3 (t53=3.86, p<0.01) were also higher in university clinic patients. CONCLUSIONS : These results suggest that the dental setting is a relevant factor when planning dental implant surgery...

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.