Effect of the nanofilm-coated zirconia ceramic on resin cement bond strength.

Background. New surface treatments have been proposed to expand the clinical indications of zirconia prostheses. This study aimed to evaluate the effect of silica and fluorine nanofilms on zirconia ceramic on the resin cement bond strength. Methods. Zirconia blocks and discs underwent different surface treatments: untreated zirconia (CON), sandblasted, silica-coated alumina particles (30 µm) (SC), silica nanofilm (SN), and fluorine nanofilm (FN). Nanofilm deposition was performed through plasma enhanced chemical vapor deposition (PECVD). Zirconia surfaces were characterized on disks by morphology (atomic force microscopy, AFM), chemical analysis (x-ray photoelectron spectroscopy, XPS), and contact angle analysis. A silane coupling agent was applied on each treated surface, and a cylinder of resin cement was built up. Half of the specimens in each group were submitted to 6000 thermal cycles (TC). Bond strength was analyzed using the shear test, and the fractographic analysis was performed with stereomicroscopy and SEM/EDS. Statistical analysis was performed through one-way ANOVA and Tukey test in the non-aged and aged specimens. Results. Nanofilms modified the zirconia surface, which became more hydrophilic and chemically reactive. Chemical bonding between Si-O was found in SN, and FN promoted a fluorination process on the ceramic surface, converting zirconia into zirconium oxyfluoride. Specimens of the SN (TC) group failed on pre-testing. FN (TC) bond strength (3.8 MPa) was lower than SC (TC) and CON (TC) after shearing. Adhesive failure predominated in the experimental groups. Silica nanofilm failure occurred after aging. Conclusion. Silica and fluorine nanofilms deposited by PECVD did not promote effective bonding between zirconia and resin cement.

Effect of Titanium Hardness on the Integrity and Stress Concentration of External Hexagon Dental Implants

ABSTRACT: The aim of this study was to evaluate the influence of overtorque on integrity, strength and stress on external hexagonal implants (EH), with two different grades (N=10): conventional (C), grade 4; and modified (M), grade 4 with thermal treatment. The dimensions of EH were 3.75 x 13 mm; the specimens were fixed and submitted to SEM analysis and image acquisition. The abutment was then retained with 70 N/cm, re-analyzed by SEM, and a second image was obtained. The images were analyzed by Image J software (1.44o- NIH, USA) for dimensional variations measurement on surface of the hexagonal area. The finite element method was applied with a similar compliance to calculate the resultant stress (MPa) during the torque. Results were statistically analyzed with t-student test (5 %). The dimensional accuracy of M (0.22 mm2) was statistically significant (p<0.05). Minimum principal stress and von-Mises stress of C (-19.95 MPa, -19.94 MPa), were lower than M values (-55.83 MPa, -55.96 MPa), respectively. However, the M group showed lower deformation than C group. Therefore, more rigid titanium alloy is a promising alternative to avoid plastic deformation of prosthetic connec tions even concentrating higher stress magnitude on its structure.

RESUMEN: El objetivo de este estudio fue evaluar la influencia del sobrepar en la integridad, la fuerza y la tensión en los implantes hexagonales externos (EH), con dos grados diferentes (N = 10): convencional (C), grado 4; y modificado (M), grado 4 con tratamiento térmico. Las dimensiones de EH eran 3,75 de diámetro x 13 mm de longitud; las muestras se fijaron y se sometieron a análisis SEM y adquisición de imágenes. A continuación, el pilar se retuvo con 70 N / cm, se volvió a analizar por SEM y se obtuvo una segunda imagen. Las imágenes se analizaron con el software Image J (1.44o-NIH, EE. UU.) Para medir las variaciones dimensionales en la superficie superior del área hexagonal, que fue causada por un par excesivo. El método de los elementos finitos se aplicó con un cumplimiento similar para calcular la tensión resultante (MPa) durante el par. Los resultados se analizaron estadísticamente con la prueba t-student (5 %). La precisión dimensional de M (0,22 mm2) fue estadísticamente significativa (p <0,05). La tensión principal mínima y la tensión de von-Mises de C (-19,95 MPa, -19,94 MPa), fueron inferiores a los valores de M (-55,83 MPa, -55,96 MPa), respectivamente. Sin embargo, el hexágono del grupo M mostró menor deformación que el grupo C. Por lo tanto, la aleación de titanio más rígida es una alternativa prometedora para evitar la deformación plástica de las conexiones protésicas incluso concentrando una mayor magnitud de tensión en su estructura.

Effect of DLC Films with and without Silver Nanoparticles Deposited On Titanium Alloy.

Diamond-like carbon (DLC) film is a biocompatible hard coating material that can prevent the leaching of metal ions. This study evaluates the structural characteristics of DLC, with and without silver nanoparticles, deposited by plasma (PECVD) on titanium alloy (Ti-6Al-4V) and bone formation in contact with DLC films. Sixty Ti-6Al-4V samples were used divided in: uncoated, coated with DLC and coated with DLC-Ag. After structural characterization, samples were fixed bilaterally at the rabbit's mandible. After 15 and 90 days, samples were characterized again and bone formation in the area was analyzed by histomorphometry. Statistical analysis was performed by two-way ANOVA. Both the DLC and DLC-Ag films were firmly adhered and showed a high electrical resistance without significant changes in the Raman spectrum after in vivo integration. After 15 days, there were immature bone trabeculae in the interface and partially covering the surface. After 90 days, mature bone filled the interface and coved the surface. There was no statistically significant difference among the three groups in both periods. In conclusion, osseointegration with DLC, DLC-Ag and uncoated Ti-6Al-4V is similar. However, DLC and DLC-Ag coverings have the advantage of electrical insulation and can presumably control bacterial activity and ion leaching.

Silicon-based film on the yttria-stabilized tetragonal zirconia polycrystal: Surface and shear bond strength analysis.

AIM: To analyze the effect of a silicon (Si)-based film deposited on yttria-stabilized tetragonal zirconia polycrystal (Y-TZP) on the topography and bond strength of resin cement. METHODS: Specimens of zirconia were obtained and randomly divided into 4 groups, according to surface treatment: polished group (PG) zirconia; sandblasted group (SG) zirconia with aluminum oxide (100 µm); after polished, zirconia was coated with Si-based film group (SiFG); and after sandblasted, zirconia was coated with Si-based film group (SiFSG). The Si-based films were obtained through plasma-enhanced chemical vapor deposition. Surface roughness and contact angle analysis were performed. Resin cement cylinders were built up on the treated surface of blocks, after applying Monobond-S. The specimens were submitted to thermocycling aging and shear bond strength testing. The Kruskal-Wallis and Mann-Whitney U-tests were performed. RESULTS: There were significant differences between the surface treatments for each roughness parameter measured. Si-based film increased roughness and decreased the contact angle. Si-based film groups also demonstrated significantly lower bond strength values. CONCLUSION: Si-based film produced using plasma deposition provided lower bond strength to resin cement compared with conventional treatment; however, the film deposition reduced the contact angle and improved roughness, favorable properties in the long way to prepare an optimum material.

Diamond-like carbon films over reconstructive TMJ prosthetic materials: Effects in the cytotoxicity, chemical and mechanical properties.

Increasingly more young patients have been submitted to reconstruction of the Temporomandibular Joint (TMJ), so, the prostheses must to present more functional longevity. OBJECTIVE: To evaluate the effect of diamond-like carbon film (DLC) over titanium alloy (Ti6Al4V) and polyethylene (UHWPE) samples, their mechanical and chemical properties and cellular cytotoxicity. METHODS: Titanium and UHWPE specimens, with 2.5 cm in diameter and 2 mm thickness were coated through plasma enhanced chemical vapor deposition (PECVD) with DLC or DLC doped with silver (DLC-Ag). Scanning electron microscopy (SEM) morphological analysis, Energy-dispersive spectroscopy (EDS) chemical analysis, scratching test, mechanical fatigue test, surface roughness analysis, and cellular cytotoxicity were performed. Data were statistically analyzed using one-way ANOVA (p < 0.05) or two-way ANOVA and multiple comparison Tukey test. RESULTS: In the SEM analysis, morphological differences were observed on substrates after DLC deposition. The film chemically modified the substrate surfaces, according to the EDS analysis. The initial critical load failure occurred at 6.1 N for DLC and 9.7 N for the DLC-Ag film. The DLC film deposition over the polyethylene promoted a decrease in the polymer's damaged area after mechanical fatigue cycling. The cytotoxicity analysis demonstrated less biocompatibility in experimental groups, when compared to control, however, increased biocompatibility was observed, at 10 days, in all groups. CONCLUSION: The diamond-like carbon coating enhanced the chemical and mechanical properties from substrates, however modified biological interaction course of the titanium alloy (Ti6Al4V) and polyethylene (UHWPE) samples. Parameters for film deposition remain to be improved in order to obtain best biocompatibility.

Reverse torque evaluation in indexed and nonindexed abutments of Morse Taper implants in a mechanical fatigue test.

BACKGROUND: This experimental study assessed reverse torque of indexed and nonindexed (NI) abutments in Morse Taper (MT) implants in a mechanical fatigue test. MATERIALS AND METHODS: In this experimental study It was used 37 implants MT and over them installed Pilar Flex abutments (4.8 mm × 6 mm × 1.5 mm). The groups were as follows: Group A used 19 MT implants with a NI Pilar Flex abutment loaded with 32 N/cm and Group B used 18 MT implants with an indexed (IN) Pilar Flex abutment loaded with 20 N/cm. The abutments were tested according to ISO standard 14801/2007. The specimens were installed at 30° from the axial axis and underwent a 133 N load, 4 Hz frequency, and 1,000,000 cycles. Once the test was completed, the reverse torque was provided by an electronic torque meter. Data were submitted to statistical analysis using the t-test for independent samples and paired t-test. The significance level was considered P < 0.05. RESULTS: Results obtained showed that the indexed Pilar Flex abutment had a percentage of torque loss from the initial torque of 49% and the NI Pilar Flex abutment lost 14%. Paired Student's t-tests revealed that for both NI (P < 0.001) and indexed (P < 0.001) abutments, the counter torque values were significantly lower than those applied at the initial torque. CONCLUSION: According on the methodology used, the NI Pilar Flex abutment was more effective regarding the reverse torque in single-unit implant prostheses versus the indexed Pilar Flex abutment. A greater loosening in the indexed Pilar Flex abutment retaining screw was noted in the reverse torque test, and the Pilar Flex abutment failed to show good outcomes related to the cold welding effect.

Efeito do filme de carbono DLC aplicado por plasma como recobrimento em Polietileno de Ultra Densidade e Alto Peso Molecular (UHWPE) e planejamento virtual utilizando a técnica de elementos finitos em cirurgias de próteses totais da ATM / The effect of DLC film applied by plasma coating deposition of Ultra high molecular weight polyethylene (UHWPE) in total ATM prosthesis and it virtual planning using the FEA technique

Este trabalho teve por objetivo avaliar o efeito do filme de carbono (DLC) aplicado por plasma como recobrimento da liga de Ti -6Al-4V e do polietileno de alto peso molecular (UHMWPE) em prótese totais de ATM, com a finalidade de melhorar suas propriedades bio-tribológicas. Outro aspecto abordado neste trabalho a aplicação do planejamento virtual utilizando a técnica de elementos finitos (FEA), na apresentação de um caso clínico, colocando a importância do cirurgião de conhecer a fundo tanto o planejamento cirúrgico quanto o desenvolvimento da prótese customizadas (TMJ), e assim evitar possíveis falhas biomecânicas. Material: Para o desenvolvimento deste trabalho primeiramente foram utilizados 40 corpos de prova de Ti-6Al-V, dos quais 15 foram recobertas com um DLC e 15 por DLC-Ag pelo método de deposição químico (PECVD), e 10 foram mantidos sem recobrimento como controle. Além disso, foram confeccionados 30 corpos de prova de UHMWPE, dos quais, 15 foram recobertas por DLC pelo sistema de deposição físico (CVD) e 15 foram mantidas sem recobrimento como controle. Métodos: Foram avaliadas as características superficiais das amostras, adesão em simulador de fadiga deslizante reproduzindo o trabalho condili fossapo 2000,000 de ciclos em banho com ringuer lactato a 36 graus, a uma carga 200 N. As amostras com filmes foram submetidas a teste de citotoxicidade com células osteoblásticas. Resultados: As células se mostraram uma biocompatibilidade significativa com as amostras portando filme de DLC em substrato Ti6Al4v, se mostrando inerte ao polietileno. Neste estudo também foi apresentado um caso clinico, paciente com 12 anos de idade genero feminino, portadora de anquilose bilateral da ATM relatou já ter sido submetida a cirurgias repetidas sem sucesso, apresentando deformidade esqueletal classe II, em consequência da anquilose temporomandibular,abertura bucal limitada inicial (4,9 mm) e pós cirúrgico reconstrução bilateral com prótese total de ATM...

This study aimed to evaluate the effect of carbon film (DLC) applied by plasma ascoating the Ti-6Al-4V alloy and ultra high molecular weight polyethylene(UHMWPE) in total TMJ prosthesis, in order to improve their bio-tribologicalproperties. Another aspects addressed in this work are the application of virtualplanning using the technique of finite element (FEA) and the presentation of a case, placing the importance of the surgeon to know the background both surgical planning and the development of customized prosthesis (TMJ) and thus avoid possible biomechanical faults. Material: For the development of this work were first used 40 specimens of Ti-6Al-V, of which 15 were coated with a DLC and 15 DLC-Ag by chemical deposition method (PECVD), and 10 were kept without coating as control. In addition, they made 30 UHMWPE specimens, of which 15 were coated with DLC by physical deposition system (CVD) and 15 were maintained without coating as a control. Methods: The surface characteristics of the samples were evaluated for adhesion sliding fatigue tester reproducing the work condili fossapo 2000.000 cycles in banhocom ringuer lactate at 36 degrees,to a load 200 N. The film samples were subjected to cytotoxicity testing inosteoblastic cells. Results: The cells showed a significant biocompatibility with samples carrying DLC film on Ti6Al4V substrate, showing inert to thepolyethylene. This study also presented a clinical case patient with 12 years offemale gender age, bearer of bilateral ankylosis of the TMJ reported having been subjected to repeated unsuccessful attempts, with deformity skeletal class II, as a result of temporomandibular ankylosis, limited mouth opening initial (4.9 mm) and post surgical bilateral reconstruction with customized ATM denture after surgery, showed up with an opening (23 mm) after one year, with a significant improvement for food and severe sleep apnea. Conclusion: Dlc titanium within the parameterswe can deposition, is presented...

Efeito do filme de carbono DLC aplicado por plasma como recobrimento em Polietileno de Ultra Densidade e Alto Peso Molecular (UHWPE) e planejamento virtual utilizando a técnica de elementos finitos em cirurgias de próteses totais da ATM / The effect of DLC film applied by plasma coating deposition of Ultra high molecular weight polyethylene (UHWPE) in total ATM prosthesis and it virtual planning using the FEA technique

Este trabalho teve por objetivo avaliar o efeito do filme de carbono (DLC) aplicado por plasma como recobrimento da liga de Ti -6Al-4V e do polietileno de alto peso molecular (UHMWPE) em prótese totais de ATM, com a finalidade de melhorar suas propriedades bio-tribológicas. Outro aspecto abordado neste trabalho a aplicação do planejamento virtual utilizando a técnica de elementos finitos (FEA), na apresentação de um caso clínico, colocando a importância do cirurgião de conhecer a fundo tanto o planejamento cirúrgico quanto o desenvolvimento da prótese customizadas (TMJ), e assim evitar possíveis falhas biomecânicas. Material: Para o desenvolvimento deste trabalho primeiramente foram utilizados 40 corpos de prova de Ti-6Al-V, dos quais 15 foram recobertas com um DLC e 15 por DLC-Ag pelo método de deposição químico (PECVD), e 10 foram mantidos sem recobrimento como controle. Além disso, foram confeccionados 30 corpos de prova de UHMWPE, dos quais, 15 foram recobertas por DLC pelo sistema de deposição físico (CVD) e 15 foram mantidas sem recobrimento como controle. Métodos: Foram avaliadas as características superficiais das amostras, adesão em simulador de fadiga deslizante reproduzindo o trabalho condili fossapo 2000,000 de ciclos em banho com ringuer lactato a 36 graus, a uma carga 200 N. As amostras com filmes foram submetidas a teste de citotoxicidade com células osteoblásticas. Resultados: As células se mostraram uma biocompatibilidade significativa com as amostras portando filme de DLC em substrato Ti6Al4v, se mostrando inerte ao polietileno. Neste estudo também foi apresentado um caso clinico, paciente com 12 anos de idade genero feminino, portadora de anquilose bilateral da ATM relatou já ter sido submetida a cirurgias repetidas sem sucesso, apresentando deformidade esqueletal classe II, em consequência da anquilose temporomandibular,abertura bucal limitada inicial (4,9 mm) e pós cirúrgico reconstrução bilateral com prótese total de ATM ...

This study aimed to evaluate the effect of carbon film (DLC) applied by plasma ascoating the Ti-6Al-4V alloy and ultra high molecular weight polyethylene(UHMWPE) in total TMJ prosthesis, in order to improve their bio-tribologicalproperties. Another aspects addressed in this work are the application of virtualplanning using the technique of finite element (FEA) and the presentation of a case, placing the importance of the surgeon to know the background both surgical planning and the development of customized prosthesis (TMJ) and thus avoid possible biomechanical faults. Material: For the development of this work were first used 40 specimens of Ti-6Al-V, of which 15 were coated with a DLC and 15 DLC-Ag by chemical deposition method (PECVD), and 10 were kept without coating as control. In addition, they made 30 UHMWPE specimens, of which 15 were coated with DLC by physical deposition system (CVD) and 15 were maintained without coating as a control. Methods: The surface characteristics of the samples were evaluated for adhesion sliding fatigue tester reproducing the work condili fossapo 2000.000 cycles in banhocom ringuer lactate at 36 degrees,to a load 200 N. The film samples were subjected to cytotoxicity testing inosteoblastic cells. Results: The cells showed a significant biocompatibility with samples carrying DLC film on Ti6Al4V substrate, showing inert to thepolyethylene. This study also presented a clinical case patient with 12 years offemale gender age, bearer of bilateral ankylosis of the TMJ reported having been subjected to repeated unsuccessful attempts, with deformity skeletal class II, as a result of temporomandibular ankylosis, limited mouth opening initial (4.9 mm) and post surgical bilateral reconstruction with customized ATM denture after surgery, showed up with an opening (23 mm) after one year, with a significant improvement for food and severe sleep apnea. Conclusion: Dlc titanium within the parameterswe can deposition, is presented..

Implantodontia guiada no tratamento estético-reabilitador de alto desempenho: qualidade e agilidade / Guided implantology in high performance rehabilitation aesthetic treatment: quality and speed

O objetivo deste estudo foi relatar um caso clínico no qual foi utilizado o sistema KEA-TECH, para planejamento e confecção do guia tomográfi co/cirúrgico na colocação de implante cone-morse com carga imediata. Foi proposta ao paciente (sexo masculino, 69 anos), com fratura radicular do elemento 11, a utilização da coroa natural remanescente como elemento provisório imediato. Pôde-se concluir que o planejamento adequado garante sucesso na reabilitação com implantes em áreas estéticas. Além disso, a utilização do sistema KEA-TECH proporciona facilidade e rapidez nos procedimentos clínicos.

The aim of this study was to report a clinical case where the KEA-TECH system was used to plan the tomographic/surgical guide and place a morse cone implant for immediate loading. The male, 69 years-old patient presented a root fracture at tooth 11, and his natural crown was used as a provisional immediate restoration. It was demonstrated that the adequate planning guarantees the success of implant rehabilitation in esthetic areas. Besides, the use of the KEA-TECH system allows for an easier and speed procedure at the daily clinics.

Influência de diferentes tratamentos de superfície em uma cerâmica policristalina de zircônia tetragonal (ytzp), na resistência de união com cimento resinoso / Influence of different surface treatments in polycrystalline tetragonal zirconia ceramic (YTZP) in bond strength with resin cement

Este estudo avaliou, in vitro, a influencia de diferentes tratamentos de superficie na resistencia de uniao ao cisalhamento entre uma ceramica de zirconia tetragonal policristalina estabilizada com itria (Y-TZP) e um cimento resinoso. Amostras com tamanho minimo de (1,5 X 1,5cm) uma ceramica de Y-TZP foram confeccionados e sintetizados, de acordo com as recomendacoes do fabricante, e limpos sonicamente em agua destilada por 10 min. De acordo com os fatores gtratamento de superficieh e gpresenca de filme a base de Sih, os blocos foram aleatoriamente divididos em 6 grupos: G1) polido; G2) polido revestido com filme; G3) jateamento com particulas (110ƒÊm) de alumina revestida por silica; G4) jateamento com particulas (110 ƒÊm) de alumina revestida por silica revestido com filme; G5) jateamento com particulas (100ƒÊm) de alumina; G6) jateamento com particulas de alumina. Os filmes foram crescidos sobre a superficie ceramica pelo metodo quimico de deposicao a plasma utilizando o hexamethylsiloxano em forma de vapor. Cilindros (cilindros O: 2,4 mm; 4 mm altura) de um cimento resinoso (Rely X U100/3M ESPE) foram confeccionados sobre a superficie da ceramica apos o tratamento de superficie (n=10). As amostras foram submetidas ao ensaio de resistencia ao cisalhamento em maquina de ensaio Universal (EMIC) a velocidade de 1 mm/min. utilizando celula de carga de 50Kgf. Os dados obtidos foram submetidos ao teste ANOVA dois fatores e ao teste Tukey com variancia aceitavel de 0,05%. Resultados: O estudo revelou que o filme interferiu negativamente nos resultados de resistencia adesiva para a superficie jateada com oxido de aluminio e nao interferiu nos resultados dos demais tratamentos de superficie Conclusao: O tratamento de superficie, com filme de plasma contendo hexamethilsiloxano em forma de vapor (HMDSO), ...

This in vitro study evaluated the influence of different surface treatments on shear bond strength between a polycrystalline ceramic tetragonal zirconia stabilized with yttria (Y-TZP) and a resin cement. Minimum number of blocks (1.5 X 1.5 cm) of a ceramic Y-TZP were prepared and synthesized according to the manufacturer's recommendations, and sonically cleaned in distilled water for 10 min. According to the factors "surface treatment" and "presence of Si-based film", the blocks were randomly divided into six groups: G1) polished; G2) polished film-coated, G3) blasting particles (110ƒÊm) of alumina coated silica; G4) blasting particles (110 mM) of alumina-coated silica-coated film; G5) blasting particles (100ƒÊm) of alumina and G6) sandblasting with alumina particles. The films were grown on the ceramic surface by chemical method using plasma deposition hexamethylsiloxane in vapor form. Cylinders (2.4 mm x O 4 mm thick) of a cement (ESPE U100/3M Rely X) were prepared on the ceramic surface after the surface treatment (n = 10). The samples were submitted to shear bond strength in an universal testing machine (EMIC) at a speed of 1 mm / min. using a 50kgf load cell. The data were subjected to two-factor ANOVA and Tukey test with acceptable variance of 0.05%. Results: The study revealed that the film had a negative influence on bond strength to the surface blasted with aluminum oxide and did not interfere with the results of other surface treatments. Conclusion: The surface treatment with plasma containing hexamethylsiloxane film in vapor form (HMDSO) did not produce better bond strength values by the method of shear type knife when compared to gold standard system blasting Rocatec (3M/ESPE). Thethermal cycling diminished the bond strength values found in all treatments

Occlusal splint for sleep bruxism: an electromyographic associated to Helkimo Index evaluation.

This study aims to evaluate long-term effects of using an occlusal splint in patients with sleep bruxism (SB), using surface electromyography (EMG) of masseter and temporalis muscles, as well as the Helkimo Index. The subjects were 15 individuals aged from 19 to 29 years, bearers of SB, with presence of signs and symptoms of temporomandibular disorders (TMD), which never have used occlusal splints. The subjects answered the Helkimo's Index and underwent EMG before and after 60 days of occlusal splints use. There was no indication of a significant decrease in mean EMG levels over the therapy in the muscles. A significant decrease in TMD signs and symptoms were observed in SB patients after 60 days of occlusal splints therapy.

Electromyographic analysis of masseter women presenting sleep bruxism after occlusal splints wearing: a pilot study / Análise eletromiográfica de masseter em mulheres apresentando bruxismo do sono após o uso de placas miorrelaxantes: um estudo piloto

Este artigo tem por objetivo analisar a atividade elétrica dos músculos massteres por meio da eletromiografia de superfície (EMG) e a eficiência das placas miorrelaxantes em mulheres portadoras de bruxismo do sono (BS). SB foi definido por suas características clínicas. Para o estudo da EMG de superfície, um sistema de registro dos sinais foi utilizado e eletrodos bipolares de prata de 10mm de diãmetro foram posicionados sobre os pontos motores dos músculos. A coleta dos sianis foi realizada na posição de oclusão mandibular sem apertar e registrou recepção dos sinais dos músculos masseteres em todos os indivíduos após um dia normal de trabalho sem utilização de placas miorrelaxantes; e, a segunda, após uma noite de sono com o uso de placas miorrelaxantes em ambos os lados. Os mesmos resultados foram verificados na posição de máxima contração voluntária. Esses resultados confirmam que o uso de placas miorrelaxantes em mulheres portadoras de bruxismo do sono reduz a atividade mioelétrica dos masseteres esquerdo e direito, mostrnado seu efeito miorrelaxante

Este artigo tem por objetivo analisar a atividade elétrica dos músculos masseteres por meio da eletromiografia de superfície (EMG) e a eficiência das placas miorrelaxantes em mulheres portadoras de bruxismo do sono (BS). SB foi definido por suas características clínicas. Para o estudo da EMG de superfície, um sistema de registro dos sinais foi utilizado e eletrodos bipolares de prata de 10 mm de diâmetro foram posicionados sobre os pontos motores dos músculos. A coleta dos sinais foi realizada na posição de oclusão mandibular sem apertar e na posição de máxima contração voluntária em duas situações distintas. A primeira coleta registrou recepção dos sinais dos músculos masseteres em todos os indivíduos após um dia normal de trabalho sem utilização de placas miorrelaxantes; e, a segunda, após uma noite de sono com o uso de placas miorrelaxantes. Avaliando os músculos masseteres durante a oclusão mandibular sem apertamento, foi observado que valores menores dos sinais EMG foram encontrados após o uso de placas miorrelaxantes em ambos os lados. Os mesmos resultados foram verificados na posição de máxima contração voluntária. Esses resultados confirmam que o uso de placas miorrelaxantes em mulheres portadoras de bruxismo do sono reduz a atividade mioelétrica dos masseteres esquerdo e direito, mostrando seu efeito miorrelaxante.

O papel das bactérias orais em doenças sistêmicas / The role of oral bacteria in systemic diseases

O uso de filogenia molecular sem a necessidade de cultura permitiu aos pesquisadores da área odontológica constatar que os biofilmes orais são comunidades microbianas com maior diversidade de bactérias do que se acreditava. Recentemente, estudos estatísticos relacionaram saúde oral precária a doenças sistêmicas e outras investigações demonstraram que alguns dos componentes da microbiota oral podem causar moléstias sistêmicas. Estes componentes podem ser tanto patógenos periodontais bem conhecidos, apresentando a capacidade de promover lesões em outros tecidos humanos; quanto bactérias oportunistas que também colonizam o biofilme. As alternativas clínicas para minimizar estes problemas incluem a promoção da saúde oral em populações específicas. Já as abordagens em pesquisa incluem os estudos em nível molecular, proporcionando uma grande sensibilidade na detecção de microrganismos e conhecimento mais abrangente sobre os mecanismos de interação entre as bactérias orais e o hospedeiro. O objetivo deste artigo é discutir o papel das bactérias orais nas doenças sistêmicas e os diferentes desafios para os pesquisadores nesse campo>