Losartan improves alveolar bone dynamics in normotensive rats but not in hypertensive rats

Abstract Hypertension is one of the main causes of premature death in the world; also, it is associated with several bone alterations. Preclinical studies have demonstrated delayed alveolar bone healing in hypertensive rats. However, losartan has been favorable for consolidation of bone grafts and reduction in active periodontitis. Therefore, losartan is suggested to be effective in bone formation stages, as well as in the synthesis of matrix proteins and mineralization. Objectives: To evaluate the alveolar bone dynamics in hypertensive rats treated with losartan by laser confocal microscopy and histological analysis. Methodology: Thirty-two rats, 16 spontaneously hypertensive rats (SHR) and 16 Wistar albinus rats, treated or not with losartan (30 mg/kg/day) were used. Calcein fluorochrome at 21 days and alizarin red fluorochrome at 49 days were injected in rats (both 20 mg/kg). The animals were submitted to euthanasia 67 days after treatment, and then the right maxilla was removed for laser confocal microscopy analysis and the left maxilla for histological analysis. Results: This study showed a greater calcium marking in normotensive animals treated with losartan in relation to the other groups. Laser confocal microscopy parameters showed higher values of bone volume formed, mineralized surface, active surface of mineralization and bone formation rate in normotensive animals treated with losartan. However, a smaller mineralized surface was observed in all hypertensive animals. Conclusion: Losartan can improve bone mineralization parameters under normal physiological conditions, but the same anabolic effect does not occur under hypertension.

Influência do número de roscas e da densidade dos blocos de poliuretano na estabilidade primária de implantes do sistema intraoss / The influence of implant thread number and polyurethane block density on primary stability values of the Intraoss implant system

Objetivo: avaliar e comparar a estabilidade primária dos implantes cilíndricos de 3,75 mm x 11 mm Titaoss e Titaoss dupla rosca, do Sistema Intraoss, instalados em blocos de poliuretano com baixa densidade. Material e métodos: foram realizadas 32 cavidades em dois blocos de poliuretano, simulando as densidades de ossos tipo III e IV. As estabilidades dos implantes foram mensuradas por meio do torque de inserção e frequência de ressonância. Resultados: os implantes Titaoss instalados no osso tipo III apresentaram valores de torque de inserção de 43,1 ± 14,87 Ncm, enquanto os valores dos implantes Titaoss dupla rosca foram 46,9 ± 5,3 Ncm. No osso tipo IV, os implantes Titaoss apresentaram valores de 30 ± 0,0 Ncm e os dupla rosca de 29,4 ± 1,77 Ncm. Não houve diferença significante na estabilidade primária entre os grupos dos implantes (p > 0,05) instalados no mesmo tipo de osso. Os implantes Titaoss instalados no osso tipo III apresentaram valores de ISQ de 57,3 ± 4,69, ao passo que os valores para os implantes Titaoss dupla rosca foram 54,9 ± 3,98. No osso tipo IV, os implantes Titaoss apresentaram valores de 48,4 ± 4,07 ISQ e os dupla rosca de 50,8 ± 3,98 ISQ. As estabilidades primárias dos implantes foram maiores no osso tipo III quando comparado ao IV (p < 0,05). Conclusão: os dois desenhos de implantes permitem a obtenção da estabilidade primária para a técnica da carga mediata. No entanto, para submeter esses tipos de implante à carga imediata, indica-se a técnica da subfresagem.

Objectives: this in vitro study aimed to evaluate and compare the primary stability of the cylindrical implants (3.75 mm x 11 mm) Titaoss and Titaoss double thread from Titaoss System placed in cavities made of low-density polyurethane blocks. Material and methods: 32 cavities were made in two types of polyurethane blocks simulating the type III and IV bone densities. The implant stability values were measured using the final insertion torque and resonance frequency analysis. Results: the Titaoss implants placed in type III bone achieved 43.1 ± 14.87 Ncm, while the double-thread values were 46.9 ± 5.3 Ncm. For bone type IV, the Titaoss implants reached 30Ncm and the double thread 29.4± 1.77 Ncm. No statistically significant differences on implant stability were seen for both groups (p > 0.05) for the same bone type. the Titaoss implants in bone type III had 57.3 ± 4.69 and the double thread 54.9 ± 3.98 ISQ values. In type IV bone, Titaoss reached 48.4 ± 4.07 and the double thread 50.8 ± 3.98 ISQ units. The primary stability values were greater at type III than type IV bone (p < 0.05). Conclusion: both implant designs allow for primary stability. However, the use of an underpreparation technique is recommended in cases of immediate loading protocols.

Alveolar bone healing in rats: micro-CT, immunohistochemical and molecular analysis

Abstract Alveolar bone healing after upper incisor extraction in rats is a classical model of preclinical studies. The underlying morphometric, cellular and molecular mechanism, however, remains imprecise in a unique study. Objectives The aim of this study was therefore to characterize the alveolar bone healing after upper incisor extraction in rats by micro computed tomographic (Micro-CT), immunohistochemical and real-time polymerase chain reaction (RT-PCR) analysis. Material and Methods Thirty animals (Rattus norvegicus, Albinus Wistar) were divided into three groups after upper incisors extraction at 7, 14, and 28 days. Micro-CT was evaluated based on the morphometric parameters. Subsequently, the histological analyses and immunostaining of osteoprotegerin (OPG), receptor activator of nuclear kappa B ligand (RANKL) and tartrate resistant acid phosphate (TRAP) was performed. In addition, RT-PCR analyses of OPG, RANKL, the runt-related transcription factor 2 (RUNX2), osteocalcin (OC), osteopontin (OPN), osterix (OST) and receptor activator of nuclear kappa B (RANK) were performed to determine the expression of these proteins in the alveolar bone healing. Results Micro-CT: The morphometric parameters of bone volume and trabecular thickness progressively increased over time. Consequently, a gradual decrease in trabecular separation, trabecular space and total bone porosity was observed. Immunohistochemical: There were no differences statistically significant between the positive labeling for OPG, RANKL and TRAP in the different periods. RT-PCR: At 28 days, there was a significant increase in OPG expression, while RANKL expression and the RANKL/OPG ratio both decreased over time. Conclusion Micro-CT showed the newly formed bone had favorable morphometric characteristics of quality and quantity. Beyond the RUNX2, OC, OPN, OST, and RANK proteins expressed in the alveolar bone healing, OPG and RANKL activity showed to be essential for activation of basic multicellular units during the alveolar bone healing.

Daily melatonin administration improves osseointegration in pinealectomized rats

Abstract The hypothesis of this study was that the peri-implant bone healing of the group of pinealectomized rats would differ from the control group. The samples were subjected to immunohistochemical, microtomographic (total porosity and connectivity density), and fluorochrome (mineralized surface) analyses. Objectives The goal of this study was to investigate the cellular changes and bone remodeling dynamics along the bone/implant interface in pinealectomized rats. Material and Methods The total of 18 adult male rats (Rattus norvegicus albinus, Wistar) was divided into three groups (n=6): control (CO), pinealectomized without melatonin (PNX) and pinealectomized with melatonin (PNXm). All animals were submitted to the first surgery (pinealectomy), except the CO group. Thirty days after the pinealectomy without melatonin, the second surgery was conducted, in which all animals received an implant in each tibia (36 titanium implants with surface treatment were installed - Implalife® São Paulo, SP, Brazil). By gavage, the rats of the PNX group received the vehicle solution, and the procedure. Results Immunohistochemical analysis for runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), osteopontin (OP) and osteocalcin (OC) showed that the bone repair process in the PNXm group was similar to that of the CO group, whereas the PNX group showed a delay. The microtomographic parameters of total porosity [Po(tot)] and bone surface (BS) showed no statistically significant differences, whereas for the connective density (Conn.Dn) a statistical difference was found between the CO and PNXm groups. Fluorochrome analysis of the active mineralized surface showed statistically significant difference between the CO and PNX and between the CO and PNXm groups. Conclusion The absence of the pineal gland impaired the bone repair process during osseointegration, however the daily melatonin replacement was able to restore this response.

Bone repair access of BoneCeramic™ in 5-mm defects: study on rat calvaria

Abstract Objective: The aim of this study was to evaluate the osteoconductive potential of BoneCeramic™ on bone healing in rat calvaria 5-mm defects. Material and Methods: A 5-mm calvaria bone defect was induced in three groups and the defect was not filled with biomaterial [Clot Group (CG)], autogenous bone (AG), or Bone Ceramic Group (BCG). Animals were euthanized after 14 or 28 days and the bone tissue within the central area of the bone defect was evaluated. Results were compared using ANOVA and Tukey test (p<0.05). Immunohistochemistry was performed using primary antibodies against osteocalcin, RUNX-2, TRAP, VEGF proteins, and 3-dimensional images of the defects in μCT were obtained to calculate bone mineral density (BMD). Results: In BCG, the defect was completely filled with biomaterial and new bone formation, which was statistically superior to that in the GC group, at both time-points (p<0.001 for 14 days; p=0.002 for 28 days). TRAP protein showed weak, RUNX-2 showed a greater immunolabeling when compared with other groups, VEGF showed moderate immunostaining, while osteocalcin was present at all time-points analyzed. The μCT images showed filling defect by BCG (BMD= 1337 HU at 28 days). Conclusion: Therefore, the biomaterial tested was found to be favorable to fill bone defects for the reporting period analyzed.

Clear cell odontogenic carcinoma of the mandible: a treatment strategy

Abstract Clear cell odontogenic carcinoma (CCOC) is a rare odontogenic tumor of the jaws, histologically characterized by the presence of agglomerates of cells with eosinophilic cytoplasm. The patient, a 62-year-old Caucasian woman, presented an intraosseous lesion in the mandibular symphysis. A clinical examination revealed a discrete volumetric increase with a hard consistency, palpable to extraoral and intraoral examinations. Imaging studies revealed an extensive radiolucent area, without defined limits, extending from the region of the right second premolar to the left canine. Incisional biopsy analysis indicated a diagnosis of CCOC. The treatment proposed was segmental resection of the mandible with a safety margin. After six months without recurrence, definitive mandibular reconstruction was performed using an iliac crest graft, followed by rehabilitation with implant-supported denture after five months. After three years of post-resection follow-up, the patient has shown no evidence of recurrence or metastasis. She continues to be under follow-up. To conclude, CCOC must be considered a malignant tumor with aggressive behavior. Previous studies have shown that resection with free margins is a treatment with a lower rate of recurrence. Nevertheless, long-term follow-up is necessary for such patients.

A SERM increasing the expression of the osteoblastogenesis and mineralization-related proteins and improving quality of bone tissue in an experimental model of osteoporosis

Abstract Raloxifene is an antiresorptive drug, selective estrogen receptor modulator (SERM) used in the treatment of osteoporosis. Objective To evaluate proteins related to bone repair at the peri-implant bone in a rat model of osteoporosis treated with raloxifene. Material and Methods 72 rats were divided into three groups: SHAM (healthy animals), OVX (ovariectomized animals), and RLX (ovariectomized animals treated with raloxifene). Raloxifene was administered by gavage (1 mg/kg/day). Tibial implantation was performed 30 days after ovariectomy, and animals were euthanized at 14, 42, and 60 days postoperatively. Samples were collected and analyzed by immunohistochemical reactions, molecular analysis, and microtomographic parameters. Results RLX showed intense staining of all investigated proteins at both time points except for RUNX2. These results were similar to SHAM and opposite to OVX, showing mild staining. The PCR gene expression of OC and ALP values for RLX (P<0.05) followed by SHAM and OVX groups. For BSP data, the highest expression was observed in the RLX groups and the lowest expression was observed in the OVX groups (P<0.05). For RUNX2 data, RLX and SHAM groups showed greater values compared to OVX (P<0.05). At 60 days postoperatively, microtomography parameters, related to closed porosity, showed higher values for (Po.N), (Po.V), and (Po) in RLX and SHAM groups, whereas OVX groups showed lower results (P<0.05); (BV) values (P=0.009); regarding total porosity (Po.tot), RLX group had statistically significant lower values than OVX and SHAM groups (P=0.009). Regarding the open porosity (Po.V and Po), the SHAM group presented the highest values, followed by OVX and RLX groups (P<0.05). The Structural Model Index (SMI), RLX group showed a value closer to zero than SHAM group (P<0.05). Conclusions Raloxifene had a positive effect on the expression of osteoblastogenesis/mineralization-related proteins and on micro-CT parameters related to peri-implant bone healing.

Comparação dos padrões istopatológicos de casos em pacientes diagnosticados com Schwannoma/Neurilemmoma bucal em relação a localização acometida da lesão / Comparison of histopathological patterns of cases in patients diagnosed with Schwannoma / Neurilemmoma buccal in relation to lesion location: a review of the literature

Introdução: Revisão da literatura comparando padrões histopatológicos e localização, em casos de Schwannoma e Neurilemmoma bucal. Metodologia: A base de dados utilizada foi Pubmed / Medline. Incluídos relatos de casos de Schwannoma e Neurilemmoma, os quais estivessem completos, contendo a idade, localização, gênero, aspectos histopatológico e imunoistoquimico. Resultados: Com a análise dos dados encontrados, constatamos que o gênero Feminino foi mais acometido, região mais afetada foi a língua, a média de idade encontrada foi de 33,46 anos, o padrão histopatológico encontrado com maior frequência foi a presença de padrões Antoni A e Antoni B juntos (38 casos). Conclusão: Observamos a importância da confirmação com imunoistoquimica positiva para S-100.(AU)

Introduction: Literature review comparing histopathological patterns and location in cases of Schwannoma and / or oral Neurilemmoma. Methods: The database used was Pubmed / Medline. Including reports of Schwannoma ou Neurilemmoma cases, which were complete, containing age, location, gender, histopathology and immunohistochemistry. Results: With the analysis of the data found, we found that the female gender was more affected, the region more affected was the tongue, the mean age was 33.46 years, the most frequently found histopathological pattern was the presence of Antoni A and Antoni B patterns together (38 cases). Conclusion: We observed the importance of the confirmation with immunohistochemistry + S-100.(AU)

Taxa de sobrevivência de implantes e biomateriais no levantamento do seio maxilar com pneumatização significativa: um estudo retrospectivo com 79 pacientes, durante seis meses a dez anos / Survival rate of immediate dental implants and biomaterials after large sinus lifting procedures: a retrospective study on 79 patients with a 6-month to 10-year follow-up

Objetivo: avaliar retrospectivamente a taxa de sucesso de implantes e biomateriais após o levantamento do seio maxilar. Material e métodos: foram utilizados prontuários de pacientes tratados entre 1998 e 2014, incluídos os que possuíam rebordo maxilar com altura menor do que 5 mm. Todos os procedimentos de enxertia foram realizados com instalação de implante de forma mediata e acesso ao seio maxilar pela janela óssea lateral, colocação do biomaterial, membrana e sutura. Resultados: foram analisados 79 pacientes, tendo sido utilizados dois biomateriais. O tempo de reavaliação variou de seis meses a dez anos. Nos dados de altura óssea radiográfica antes e depois do procedimento (70 implantes, 36 pacientes), houve um aumento médio de altura na região do seio maxilar com o Bio-Oss de 17,23 mm e com o Orthogen de 13,12 mm (p < 0,05), sendo a média geral de 15,17 mm. Na relação sobrevida do implante e enxerto utilizado (92 implantes, 43 pacientes), os valores foram de 96,8% (autógeno) e 98,3% (autógeno + biomaterial). Conclusão: os resultados permitiram concluir que tanto os enxertos autógenos como os biomateriais são alternativas viáveis para os seios maxilares com grande pneumatização.

Objective: to retrospectively evaluate the success rate of implants and biomaterials after maxillary sinus lift. Material and methods: records of patients treated between 1998 and 2014 were used, including those with maxillary ridge height less than 5 mm. All grafting procedures were performed with implant placement and access to the maxillary sinus through the lateral bony window, placement of the biomaterial, membrane and suture. Results: 79 patients were analyzed and two biomaterials were used. The follow-up period ranged from six months to ten years. In the radiographic bone height data before and after the procedure (70 implants, 36 patients), there was a mean increase in height in the maxillary sinus region with the Bio-Oss of 17.23 mm and with the Orthogen of 13.12 mm (p < 0.05), the overall mean being 15.17 mm. Regarding implant and graft survival (92 implants, 43 patients), the values were 96.8% (autogenous) and 98.3% (autogenous + biomaterial). Conclusion: both autogenous grafts and biomaterials are viable alternatives for the maxillary sinuses with great pneumatization.

Short term sodium alendronate administration improves the peri-implant bone quality in osteoporotic animals

Abstract Sodium alendronate is a bisphosphonate drug that exerts antiresorptive action and is used to treat osteoporosis. Objective The aim of this study was to evaluate the bone repair process at the bone/implant interface of osteoporotic rats treated with sodium alendronate through the analysis of microtomography, real time polymerase chain reactions and immunohistochemistry (RUNX2 protein, bone sialoprotein (BSP), alkaline phosphatase, osteopontin and osteocalcin). Material and Methods A total of 42 rats were used and divided in to the following experimental groups: CTL: control group (rats submitted to fictitious surgery and fed with a balanced diet), OST: osteoporosis group (rats submitted to a bilateral ovariectomy and fed with a low calcium diet) and ALE: alendronate group (rats submitted to a bilateral ovariectomy, fed with a low calcium diet and treated with sodium alendronate). A surface treated implant was installed in both tibial metaphyses of each rat. Euthanasia of the animals was conducted at 14 (immunhostochemistry) and 42 days (immunohistochemistry, micro CT and PCR). Data were subjected to statistical analysis with a 5% significance level. Results Bone volume (BV) and total pore volume were higher for ALE group (P<0.05). Molecular data for RUNX2 and BSP proteins were significantly expressed in the ALE group (P<0.05), in comparison with the other groups. ALP expression was higher in the CTL group (P<0.05). The immunostaining for RUNX2 and osteopontin was positive in the osteoblastic lineage cells of neoformed bone for the CTL and ALE groups in both periods (14 and 42 days). Alkaline phosphatase presented a lower staining area in the OST group compared to the CTL in both periods and the ALE at 42 days. Conclusion There was a decrease of osteocalcin precipitation at 42 days for the ALE and OST groups. Therefore, treatment with short-term sodium alendronate improved bone repair around the implants installed in the tibia of osteoporotic rats.

Surgical techniques for maxillary bone grafting - literature review / Técnicas cirúrgicas para a enxertia óssea dos maxilares - revisão da literatura

For oral rehabilitation with implant-supported prostheses, there are required procedures to create the bone volume needed for installation of the implants. Thus, bone grafts from intraoral or extraoral donor sites represent a very favorable opportunity. This study aimed to review the literature on the subject, seeking to discuss parameters for the indications, advantages and complications of techniques for autogenous bone grafts.

Para a reabilitação bucal com as próteses implantossuportadas é necessário a realização de procedimentos para criar o volume ósseo necessário para a instalação dos implantes. Com isso, os enxertos ósseos provenientes de áreas doadoras intrabucais ou extrabucais, representam uma possibilidade bastante favorável. O presente trabalho objetivou realizar uma revisão da literatura em que procurou discutir parâmetros para as indicações, as vantagens e complicações para as técnicas dos enxertos ósseos autógenos.

Tumor odontogênico queratocístico - relato de caso / Odontogenic keratocyst tumor - a case report

Introdução: O Tumor Odontogênico Queratocístico (TOQ)deriva dos restos lâmina dentária com particularidades easpectos histológicos específicos, com alto índice de recidiva ecomportamento clínico agressivo. Apresenta certa predileçãopara o sexo masculino, acometendo a mandíbula de 60% a 80%dos casos, podendo estar relacionado a dente incluso de 25 a45% dos casos. Objetivo: evidenciar as características clínicas,imaginológicas e histopatológicas do TOQ, bem como discutirsobre o tratamento desta lesão. Relato de Caso: Paciente de 10anos de idade que ao procurar o ortodontista para correção demordida aberta anterior, observou-se na ortopantomografia árearadiolúcida, na região do corpo de mandíbula, associada à inclusãopatológica do pré-molar inferior. Foi realizada biópsia incisionalda lesão e o laudo histopatológico foi de tumor odontogênicoqueratocístico. Realizou-se uma tomografia computadorizadapara avaliar a extensão da lesão e sua relação com as estruturasanatômicas. Como conduta, optou-se pela extração do molarinferior decíduo e enucleação da lesão, preservando o pré-molarincluso. O mesmo segue em controle clínico-radiográfico de 18meses, após a remoção do TOQ obtendo-se a erupção do prémolarque estava envolvido na lesão. Comentários Finais: Épreciso adotar protocolos de atenção odontológica que incluemo conhecimento de diagnóstico bucal, anamnese e avaliaçãoclínica criteriosa sem esquecer a necessidade de confirmaçãohistopatológica.

The Fresh Frozen Bone Allograft (FFBA) to Reconstruct the Atrophic Maxilla: Evaluation of the Clinical and Histological Viability at Six and Nine Months in the Maxillary Sinus / Aloinjerto Óseo Fresco Congelado (FFBA) en la Reconstrucción del Maxilar Atrófico: Evaluación de la Viabilidad Clínica e Histológica a los Seis y Nueve Meses en el Seno Maxilar

This work aimed to analyze clinically and histologically the allogen bone graft behavior at 6 and 9 months. A leukoderm, female, 55 years old patient sought dental care for oral rehabilitation with dental implants and implant supported fixed prosthesis in the maxilla. Bilateral sinus lifting procedure were performed in a same patient, the analysis were made after 6 and 9 months, respectively. At 6 months, there was lack of a better bone remodeling in the region, associated to the presence of fibrous connective tissue within the collected tissue, showing us that this is not the best stage of tissue maturation to place dental implants. The 9 months period showed an improvement, with a more organized bone tissue surrounding particles of homogenous bone, what possibly had increased implant stability at the time of surgery. There is no doubt about the increase of clinical applications of FFBA, but there are no studies available regarding the standardization of time to load implants inserted in allografts. So papers with long-term monitoring are necessary to eliminate questions that still remain to be answered.

El objetivo fue analizar clínica e histológicamente el injerto óseo alógeno a los 6 y 9 meses. Una paciente sexo femenino, leucoderma de 55 años de edad consultó por atención odontológica para la rehabilitación oral con implantes y prótesis fija implanto soportada en el maxilar. Procedimientos de elevación del seno maxilar bilateralmente fueron realizados en la misma paciente, y se hicieron los análisis después del sexto y noveno mes, respectivamente. Al sexto mes, se observó una remodelación ósea deficiente de la región asociada a la presencia de tejido conectivo fibroso en el tejido analizado, demostrando que no era la mejor etapa de maduración óseo para instalar los implantes. Al noveno mes se observo una mejora, con un tejido óseo mas organizado rodeando partículas de hueso homogéneo, el cual posiblemente incrementaría la estabilidad del implante en el momento de la cirugía. No hay dudas respecto del incremento de aplicaciones clínicas del FFBA, pero no hay estudios capaces de estandarizar el tiempo de carga de los implantes instalados sobre aloinjertos. Investigaciones con seguimientos a largo plazo son necesarios para eliminar las preguntas que aun se mantienen sin respuesta.

Efeitos de diferentes concentrações de dextrose e lipopolissacarídeo no comportamento corrosivo da liga Ti-6Al-4V com superfície usinada e tratada com duplo ataque ácido / Effects of different concentrations of dextrose and lipopolysaccharide on the corrosion behavior of cpTi with machined and double acid-etched surfaces

Objetivos: Avaliar o comportamento corrosivo da liga Ti-6Al-4V em função de sua superfície polida ou condicionada por meio de duplo ataque ácido, em simulador de fluidos corporais (SFC) com diferentes concentrações de dextrose (0; 5mM; 7,5 mM e 15 mM) e lipopopolissacarídeo (LPS) (0; 0,15 μg/mL; 15 μg/mL; 150 μg/mL), usados isolados ou associados. Materiais e Métodos: Discos de liga Ti-6Al-4V (2 mm de espessura e 15 mm de diâmetro) foram confeccionados com diferentes padrões de superfície. Para o ensaio eletroquímico (n=3), testes padrões como potencial de circuito aberto, espectroscopia de impedância eletroquímica (EIE) e teste potenciodinâmico foram conduzidos em solução de fluido corpóreo (SBF) com diferentes concentrações de dextrose e LPS. As superfícies dos discos foram caracterizadas pela microscopia eletrônica de varredura (MEV), microscopia de força atômica (MFA), e por meio da rugosidade de superfície e da microdureza. Os dados quantitativos foram analisados pelo teste de correlação de Pearson e T-teste independente, com nível de significância de 5%. Resultados: Nos parâmetros de corrosão, houve forte correlação do LPS com os valores de Ipass (densidade de corrente de passivação), Cdl (capacitância) e Rp (resistência de polarização) (p<0,05) para o titânio (Ti) com tratamento de superfície por duplo ataque ácido. A associação de dextrose e LPS foi correlacionada com Icorr (densidade de corrente de corrosão) e Ipass (p<0,05). Em relação à cinética de corrosão, os grupos tratados com ácido apresentaram aumento significante nos valores de Cdl e redução nos valores de Rp (P<0,05, T-teste). Quanto à topografia, houve aumento da rugosidade de superfície para ambas as superfícies (R2=0,726, p=0,0001 para Ti polido; R2=0,405, p=0,036 para Ti ácido). A microdureza do Ti polido diminuiu (p<0,05) e do Ti ácido aumentou (p=0,0001). A MFA mostrou alteração na microestrutura do Ti por meio do aumento da espessura superficial principalmente no grupo com associação...

Objectives: To analyse the corrosion behavior of Ti-6Al-4V with different surfaces (machined and modified by treatment with double acid-etching), on simulator body fluids (SBF) with different concentrations of dextrose (0; 5 mM, 7.5 mM and 15 mM) and lipopolysaccharide (LPS) (0; 0.15 μg/mL; 15 μg/mL; 150 μg/mL), used isolated or in combination. Materials and Methods: Ti-6Al-4V disks (2 mm in thickness and 15 mm in diameter) were fabricated with different surfaces. For electrochemical assay (n = 3), open circuit potential, electrochemical impedance spectroscopy (EIS) and potentiodynamic tests were conducted in SBF with different concentrations of dextrose and LPS. The surfaces of the disks were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and by surface roughness and microhardness. Data were analyzed by Pearson correlation and independent t-test at a significant level of 5%. Results: For the corrosion parameters, a strong correlation of LPS with Ipass (passivation current density), Cdl (capacitance) and Rp (polarization resistance) values (P <.05) for Ti surface treated by double acid- etching was noted. The combination of dextrose and LPS was correlated with Ipass and Icorr (corrosion current density) (P <.05). Regarding the corrosion kinetics the acid-treated groups showed significant increase in Cdl values and reduced values of Rp (P <.05, T-test). In terms of topography, there was an increase in surface roughness for both surfaces (R2 = 0.726, p = 0.0001 for machined Ti, R2 = 0.405, p = 0.036 for Ti acid). The machined Ti exhibited reduction in microhardness (P <.05), while Ti acid showed increased microhardness (p = 0.0001) vs baseline. The AFM showed changes in the microstructure of Ti by increasing the thickness of surface mainly in the association of dextrose and LPS. Conclusions: The combination of dextrose and LPS affected the corrosion behavior of Ti-6Al-4V surface treated with double acid-etching. These results...

Efeitos de diferentes concentrações de dextrose e lipopolissacarídeo no comportamento corrosivo da liga Ti-6Al-4V com superfície usinada e tratada com duplo ataque ácido / Effects of different concentrations of dextrose and lipopolysaccharide on the corrosion behavior of cpTi with machined and double acid-etched surfaces

Objetivos: Avaliar o comportamento corrosivo da liga Ti-6Al-4V em função de sua superfície polida ou condicionada por meio de duplo ataque ácido, em simulador de fluidos corporais (SFC) com diferentes concentrações de dextrose (0; 5mM; 7,5 mM e 15 mM) e lipopopolissacarídeo (LPS) (0; 0,15 μg/mL; 15 μg/mL; 150 μg/mL), usados isolados ou associados. Materiais e Métodos: Discos de liga Ti-6Al-4V (2 mm de espessura e 15 mm de diâmetro) foram confeccionados com diferentes padrões de superfície. Para o ensaio eletroquímico (n=3), testes padrões como potencial de circuito aberto, espectroscopia de impedância eletroquímica (EIE) e teste potenciodinâmico foram conduzidos em solução de fluido corpóreo (SBF) com diferentes concentrações de dextrose e LPS. As superfícies dos discos foram caracterizadas pela microscopia eletrônica de varredura (MEV), microscopia de força atômica (MFA), e por meio da rugosidade de superfície e da microdureza. Os dados quantitativos foram analisados pelo teste de correlação de Pearson e T-teste independente, com nível de significância de 5%. Resultados: Nos parâmetros de corrosão, houve forte correlação do LPS com os valores de Ipass (densidade de corrente de passivação), Cdl (capacitância) e Rp (resistência de polarização) (p<0,05) para o titânio (Ti) com tratamento de superfície por duplo ataque ácido. A associação de dextrose e LPS foi correlacionada com Icorr (densidade de corrente de corrosão) e Ipass (p<0,05). Em relação à cinética de corrosão, os grupos tratados com ácido apresentaram aumento significante nos valores de Cdl e redução nos valores de Rp (P<0,05, T-teste). Quanto à topografia, houve aumento da rugosidade de superfície para ambas as superfícies (R2=0,726, p=0,0001 para Ti polido; R2=0,405, p=0,036 para Ti ácido). A microdureza do Ti polido diminuiu (p<0,05) e do Ti ácido aumentou (p=0,0001). A MFA mostrou alteração na microestrutura do Ti por meio do aumento da espessura superficial principalmente no grupo com associação...

Objectives: To analyse the corrosion behavior of Ti-6Al-4V with different surfaces (machined and modified by treatment with double acid-etching), on simulator body fluids (SBF) with different concentrations of dextrose (0; 5 mM, 7.5 mM and 15 mM) and lipopolysaccharide (LPS) (0; 0.15 μg/mL; 15 μg/mL; 150 μg/mL), used isolated or in combination. Materials and Methods: Ti-6Al-4V disks (2 mm in thickness and 15 mm in diameter) were fabricated with different surfaces. For electrochemical assay (n = 3), open circuit potential, electrochemical impedance spectroscopy (EIS) and potentiodynamic tests were conducted in SBF with different concentrations of dextrose and LPS. The surfaces of the disks were characterized by scanning electron microscopy (SEM), atomic force microscopy (AFM) and by surface roughness and microhardness. Data were analyzed by Pearson correlation and independent t-test at a significant level of 5%. Results: For the corrosion parameters, a strong correlation of LPS with Ipass (passivation current density), Cdl (capacitance) and Rp (polarization resistance) values (P <.05) for Ti surface treated by double acid- etching was noted. The combination of dextrose and LPS was correlated with Ipass and Icorr (corrosion current density) (P <.05). Regarding the corrosion kinetics the acid-treated groups showed significant increase in Cdl values and reduced values of Rp (P <.05, T-test). In terms of topography, there was an increase in surface roughness for both surfaces (R2 = 0.726, p = 0.0001 for machined Ti, R2 = 0.405, p = 0.036 for Ti acid). The machined Ti exhibited reduction in microhardness (P <.05), while Ti acid showed increased microhardness (p = 0.0001) vs baseline. The AFM showed changes in the microstructure of Ti by increasing the thickness of surface mainly in the association of dextrose and LPS. Conclusions: The combination of dextrose and LPS affected the corrosion behavior of Ti-6Al-4V surface treated with double acid-etching. These results...

Odontogenic keratocyst tumor: report of two cases / Tumor queratoquiste odontogénico: reporte de dos casos

In 2005, odontogenic cyst was classified as keratocyst odontogenic tumor due to being aggressive and recurrent. The keratocyst odontogenic tumor has characteristics, with slow development, does not cause metastases and provides great bone destruction. The aim of this study was to discuss the aspects regarding the diagnosis, prognosis and treatment of odontogenic keratocyst tumor, through the report of two cases. Both initially underwent decompression of the lesion present proximity of anatomical structures to be great and noble, aiming to prevent pathological fractures. We carried out the clinical-radiographic and after regression of the lesion, patients underwent enucleation total.

El año 2005 quiste odontogénico fue clasificado como un tumor queratoquiste odontogénico (TQO) debido a su agresividad y recurrencia. El TQO tiene las características del tumor: crecimiento lento, no causa metástasis y proporciona una gran destrucción ósea. El objetivo de este estudio fue examinar los aspectos relacionados con el diagnóstico, pronóstico y tratamiento del TQO mediante la presentación de dos casos. Ambos casos fueron inicialmente sometidos a descompresión debido al gran tamaño de la lesión y la proximidad de ésta con estructuras anatómicas importantes, con el objetivo de prevenir las fracturas patológicas. Se llevó a cabo un seguimiento clínico-radiográfico y después de tener una regresión de la lesión postdescompresión, los pacientes fueron sometidos la enucleación total.

O impacto das próteses implantossuportadas na harmonia facial / The impact of implant-supported prostheses in facial harmony

Grande parte da população que procura atendimento odontológico deseja melhorar a estética facial e a do sorriso, para ser inserida na sociedade em que vive. Nos indivíduos usuários de próteses totais, a reabsorção fisiológica causa uma atrofia, principalmente da maxila, sendo necessária a realização de técnicas reconstrutoras e, às vezes, de movimentação das bases ósseas, para maior estabilidade oclusal e harmonia facial. O objetivo deste trabalho foi abordar as características relacionadas com a reabilitação dos pacientes edêntulos, com indicação para a reconstrução dos maxilares com enxerto ósseo e cirurgia ortognática, por meio de um caso clínico. Sendo que após a reabilitação com as próteses implantossuportadas, a paciente se mostrou amplamente satisfeita com o resultado estético-funcional alcançado e se recusou a submeter-se à cirurgia ortognática proposta no planejamento. Com isso, os profissionais devem apresentar as opções terapêuticas aos pacientes, porém, deve prevalecer a queixa principal dos mesmos, desde que seja uma modalidade de tratamento viável.

Many patients seeking dental care wish to improve facial and smile aesthetics to be accepted in modern day society. In denture wearers, the physiological resorption causes atrophy mainly in the maxilla, being necessary to carry out reconstruction techniques and sometimes orthognathic surgery to improve occlusal stability and facial harmony. The aim of this study is to discuss the features related to the rehabilitation of edentulous patients with indication for reconstruction of the maxilla using bone grafts and orthognathic surgery by means of a clinical case. In the present case, after the prosthetic rehabilitation, the patient was full satisfied with obtained results and dismissed the initially proposed surgical protocol. Therefore, professionals should provide therapeutic options but the patient’s opinion should prevail provided its clinical feasibility.