Effects of different polishing procedures on the surface roughness and hardness of polyether ether ketone (PEEK) / Efecto de diferentes procedimientos de pulido en la rugosidad y dureza de superficie de un material a base de poliéter éter acetona (PEEK)

ABSTRACT: There is insufficient information about the chairside polishing methods of polyether ether ketone material. Therefore, it is aimed in this study to investigate the effects of different polishing processes on polyether ether ketone surface roughness and hardness. A total of 66 disc-shaped specimens made of polyether ether ketone were used in this study. The specimens were polished conventionally and randomly divided into three groups (n=22). One group was designated as the control group, and no further treatment was applied. In the other two groups, the specimens' surfaces were abraded with diamond burs and polished using two different polishing kits. Their surface roughness and Vickers hardness were measured, and environmental scanning electron microscopy and atomic force microscopy examinations were performed. The data were statistically analysed using analysis of variance and Tukey's honest significant difference test (α=0.05). There were no statistically significant differences between the control and polishing kit groups in terms of either surface roughness or Vickers hardness (p>0.05). The polishing kits can be used reliably and effectively for polishing polyether ether ketone materials.

RESUMEN: No existe información suficiente sobre los métodos de pulido del material poliéter éter cetona. Por tanto, este estudio tiene como objetivo evaluar el efecto de diferentes procedimientos de pulido sobre la rugosidad y dureza de superficie de un material a base de poliéter éter acetona. Un total de 66 muestras en forma de disco fueron realizadas. Los especímenes fueron divididos en tres grupos (n=22). Un grupo fue designado como grupo de control, siendo que no se aplicó ningún tratamiento. En los otros dos grupos, las superficies de las muestras se lijaron con fresas de diamante y se pulieron con dos kits de pulido diferentes. Se investigó la rugosidad de superficie y la dureza Vickers en los diferentes grupos. También fueron evaluadas muestras representativas en microscopía electrónica de barrido y microscopía de fuerza atómica. Los datos se analizaron estadísticamente mediante el análisis de varianza (ANOVA) y el método de Tukey (α=0.05). No hubo diferencias estadísticamente significativas entre los grupos en términos de rugosidad de superficie o Dureza Vickers (p>0,05). Los kits de pulido se pueden utilizar de forma eficaz para el pulido de materiales a base de poliéter éter acetona.

Does the addition of vitamin E to conventional UHMWPE improve the wear performance of hip acetabular cups? Micro-Raman characterization of differently processed polyethylene acetabular cups worn on a hip joint simulator

In knee replacements, vitamin E-doped ultra-high molecular weight polyethylene (UHMWPE) shows a better wear behavior than standard UHMWPE. Therefore, different sets of polyethylene (PE) acetabular cups, i.e. standard UHMWPE and cross-linked polyethylene irradiated with 50 kGy and 75 kGy, were compared, at a molecular level, with vitamin E-doped UHMWPE to evaluate their wear performance after being tested on a hip joint simulator for five million cycles. Unworn control and worn acetabular cups were analyzed by micro-Raman spectroscopy to gain insight into the effects of wear on the microstructure and phase composition of PE. Macroscopic wear was evaluated through mass loss measurements. The data showed that the samples could be divided into two groups: 1) standard and vitamin E-doped cups (mass loss of about 100 mg) and 2) the cross-linked cups (mass loss of about 30-40 mg). Micro-Raman spectroscopy disclosed different wear mechanisms in the four sets of acetabular cups, which were related to surface topography data. The vitamin E-doped samples did not show a better wear behavior than the cross-linked ones in terms of either mass loss or morphology changes. However, they showed lower variation at the morphological level (lower changes in phase composition) than the UHMWPE cups, thus confirming a certain protecting role of vitamin E against microstructural changes induced by wear testing.

Comparison of Wear Rate between Ceramic-on- Ceramic, Metal on Highly Cross-linked Polyethylene, and Metal-on-Metal Bearings / Comparação da taxa de desgaste entre componentes de cerâmica sobre cerâmica, de metal sobre polietileno de alta ligação cruzada e de metal sobre metal

Abstract Objective Currently, there is a lack of evidence on the medium-term follow-up of cementless total hip arthroplasty (THA) using metal on highly cross-linked polyethylene (MoP), ceramic-on-ceramic (CoC), and metal-on-metal (MoM) bearings. Our aim was to calculate the 5- to 10-year wear rate and the incidence rate of osteolysis for 3 types of bearings. Methods A total of 77 patients underwent MoP, 105 underwent ceramic CoC, and 55 underwent MoM THAs. The average patient age at the time of surgery was 64.7, 55.9, and 59.9 years old in the MoP, CoC, and MoM bearings, respectively. Clinical and radiologic measurements at a mean follow-up of 7.6 years were analyzed. Results The mean postoperative Harris hip scores showed no difference among the groups. The mean annual liner wear rates were 0.0160, 0.0040 and 0.0054 mm/year in MoP, CoC bearings, and MoM bearings, with that of CoC bearings being significantly lower than the others. Osteolysis (14.5%) among MoM bearings was significantly more frequently observed compared with the others. Kaplan-Meier survival at 10 years with implant loosening, or revisionTHA as the endpoint, was 96.1% (95% confidence interval [CI]: 88.4-98.7) forMoP, 98.6% (95% CI: 90.3-98.6) for CoC bearing, and 98.2% (95% CI: 88.0-99.7) for MoM bearings (p = 0.360). Conclusion Excellent clinical and radiological outcomes were obtained for MoP and CoC bearings.

Resumo Objetivo Hoje, não há evidências sobre o acompanhamento em médio prazo da artroplastia total do quadril (ATQ) não cimentada com componentes de polietileno de alta ligação cruzada (highly cross-linked) sobre metal (MoP, na sigla em inglês), de cerâmica sobre cerâmica (CoC, na sigla em inglês), e de metal sobre metal (MoM, na sigla eminglês). Nosso objetivo foi calcular a taxa de desgaste entre 5 a 10 anos e a taxa de incidência de osteólise nos 3 tipos de componentes. Métodos Um total de 77 pacientes foram submetidos a ATQ com componentes de MoP; 105 foram submetidos ao mesmo procedimento com componentes de CoC, e 55 foram submetidos à ATQ com componentes de MoM. A média de idade dos pacientes no momento da cirurgia foi de 64,7, 55,9 e 59,9 anos nos grupos de componentes MoP, de CoC, e de MoM, respectivamente. Asmedidas clínicas e radiológicas emumperíodo médio de acompanhamento de 7,6 anos foram analisadas. Resultados As pontuações médias de Harris no período pós-operatório não mostraram diferença entre os grupos. As taxas médias anuais de desgaste do revestimento foram de 0,0160, 0,0040 e 0,0054 mm/ano em componentes de MoP, de CoC, e de MoP, respectivamente; a taxa de desgaste dos componentes de CoC foi significativamente menor do que as dos demais. A osteólise (14,5%) nos componentes de MoM foi significativamente mais frequente em comparação aos demais. A sobrevida de Kaplan- Meier aos 10 anos comafrouxamento do implante ou revisão da ATQ como desfecho foi de 96,1% (intervalo de confiança [IC] de 95%: 88,4-98,7) nos componentes de MoP, de 98,6% (IC95%: 90,3-98,6) nos componentes de CoC, e de 98,2% (IC95%: 88,0-99,7) nos componentes de MoM (p = 0,360). Conclusão Os resultados clínicos e radiológicos de componentes de MoP e de CoC foram excelentes.

Antifungal efficiency of chemically and thermally-activated acrylic resins after surface treatment using poly (diallyldimethylammonium chloride)

Abstract INTRODUCTION: Acrylic resins are used in the preparation of facial prostheses and may be colonized by fungi. Here, we verified the antifungal efficacy of this material after surface treatment using poly (diallyldimethylammonium chloride). METHODS: Acrylic resin specimens with and without surface treatment were subjected to tests for fungistatic and fungicidal activities. Standard strains of Candida albicans and Aspergillus niger were used. RESULTS: After surface treatment, the fungistatic and fungicidal efficacies of the resins against C. albicans and fungistatic action against A. niger were verified. CONCLUSIONS: The surface treatment was a determinant of the antifungal activity of the material.

Comparación del confort de dos protectores bucales en jugadores de fútbol americano / Comparing the comfort of two mouth protectors in football players

Los deportes de contacto aumentan el riesgo de traumatismo causando alteraciones funcionales, estéticas y psicológicas. Los protectores bucales son parte del equipo de seguridad que protegen al deportista de estos accidentes, es importante que brinde confort para lograr el mejor rendimiento físico. Objetivo: Comparar el confort de los jugadores de fútbol americano con el uso de protectores prefabricados y protectores personalizados. Metodología: Se realizó un estudio cuasiexperimental, analítico y prospectivo donde se incluyeron 15 jugadores de futbol americano de la Facultad de Estudios Superiores Acatlán, UNAM, que firmaron consentimiento informado. La autora principal de este proyecto fabricó los protectores bucales superiores con hoja de copolímero de etilvinilacetato (EVA) #35. El protector prefabricado fue de silicón. Los jugadores realizaron dos prácticas de entrenamientos donde hicieron 30 minutos de carrera, 15 de estiramiento, 60 de fuerza y destreza en donde requerían de estar en constante comunicación verbal y 30 de cardiovascular en gimnasio (usaron un protector en cada entrenamiento). Se aplicó un cuestionario ­previamente validado por consenso de expertos­ para evaluar el confort en la respiración, lenguaje, náuseas, adaptación, comodidad e hidratación bucal con cada tipo de protector. La información se analizó en el programa SPSS v19.0; se usaron proporciones para las variables cualitativas y medidas de tendencia central y dispersión para las cuantitativas. Para comparar el confort con el uso de ambos protectores se empleó la prueba χ2, con un nivel de significancia p < 0.05. Resultados: La media de edad fue de 20 ± 2 años. Con el protector personalizado 11 jugadores (0.73) refirieron que respiraron y hablaron mejor, sintieron menos náusea 12 (0.80), mejor adaptación 11 (0.73) y mayor comodidad 12 (0.80) que, con el uso de protector bucal prefabricado, encontrando diferencias estadísticamente significativas (p < 0.05) y ocho (0.53) refirió menos hidratación bucal (p > 0.05). Doce (0.80) de los jugadores mencionaron tener mayor confort con el protector personalizado. Conclusiones: Con la metodología empleada y en la muestra estudiada, el uso de un protector bucal personalizado fabricado con hoja de copolímero de etilvinilacetato (EVA) #35 ofrece una mejor adaptación y comodidad, después de dos prácticas de entrenamiento (AU)

The contact sports, increase the risk of trauma causing functional, aesthetic and psychological alterations, mouth guards are part of the safety equipment that protects the athlete from this kind of accidents, it is also important that the mouth guard had to provides comfort, for achieve a best physical performance. Objective: Make the comparison with the comfort of American football players with the use of prefabricated protectors and customized protectors. Method: A quasi-experimental, analytical and prospective study was carried out, including 15 American football players from the Facultad de Estudios Superiores Acatlán, UNAM, who signed an informed consent. The lead author of this project manufactured the upper mouth guards with ethylvinylacetate (EVA) #35 copolymer foil. The prefabricated protector was made of silicone. The players performed two practice sessions where they did 30 minutes of running, 15 of stretching, 60 of strength and skill where they required being in constant verbal communication and 30 of cardiovascular in a gymnasium (they used a protector in each training). A questionnaire ­previously validated by expert consensus­ was applied to evaluate comfort in breathing, language, nausea, adaptation, comfort and oral hydration with each type of protector. The information was analyzed in the program SPSS v19.0; proportions were used for the qualitative variables and measures of central tendency and dispersion for the quantitative ones. To compare the comfort with the use of both protectors the test χ2 was used, with a level of signifi cance p < 0.05. Results: The mean age was 20 ± 2 years. With the personalized protector, 11 players (0.73) reported that they breathed and spoke better, feeling less nausea 12 (0.80), better adaptation 11 (0.73) and greater comfort 12 (0.80) than with the use of prefabricated mouth guards, fi nding statistically signifi cant diff erences (p < 0.05) and 8 (0.53) reported less oral hydration (p > 0.05). 12 (0.80) of players mentioned having more comfort with the custom protector. Conclusions: The use of a personalized mouth guard off ers better fi t and comfort made with sheet copolymer of ethylvinylacetate, after two training practices (AU)

Tribología moderna en artroplastía total de cadera: pros y contras / Modern tribology in total hip arthroplasty: pros and cons

Los productos de desgaste y las reacciones adversas que se generan en las superficies de rodamiento constituyen uno de los mayores desafíos en las sustituciones protéticas, ya que cada día se someten a mayores demandas por un cada vez mayor número de pacientes jóvenes y adultos mayores con expectativas de vida prolongadas y notable actividad. El objetivo de esta revisión es analizar los pros y contras en cuanto a los avances de los componentes de rodamiento de las superficies articulares de las artroplastias totales de cadera contemporáneas. También se discutirán las estrategias que se han seguido a lo largo del tiempo, sus problemas, resultados y el papel que desempeña el cirujano en la prescripción del par tribológico que mejor se adapte a las necesidades de cada paciente. Al final se hacen recomendaciones prácticas para prescripción y manejo de los pares articulares contemporáneos en artroplastia total de cadera.

The wear products and adverse reactions that occur on bearing surfaces represent one of the greatest challenges in prosthetic replacements, as the latter experience increasing demands due to the large number of young and older adult patients that have a long life expectancy and remarkable activity. The purpose of this review is to analyze the pros and cons of the new advances in the bearing components of the articular surfaces of current total hip arthroplasties. We also discuss the strategies used historically, their problems, results and the surgeon's role in prescribing the tribologic couple that best fits each patient's needs. We conclude with practical recommendations for the prescription and management of the latest articular couples for total hip arthroplasty.

Puente adhesivo en paciente con labio leporino y fisura velopalatina: una solución temporal con compromiso estético / Adhesive bridge in a patient with cleft lip and palate: a temporary solution with esthetic commitment

En la actualidad el aumento de la demanda estética y la necesidad de procedimientos mínimamente invasivos ha llevado a un aumento de la técnica adhesiva. Ribbond® es una marca de fibra de polietileno que permite un eficiente traspaso de fuerzas, es virtualmente plegable y se adapta fácilmente a la morfología dentaria y al contorno del arco dentario. Dentro de sus principales características podemos encontrar: Biocompatibilidad, inerte, translúcido y durable. Dentro de la odontología se le han dado distintos usos para esta fibra, ya sea como mantenedor de espacio, puente adhesivo, poste y núcleo endodóntico, ferulización, restauraciones tipo inlay y estabilización postortodóncica. En el caso de los pacientes fisurados se ha hecho relevante el uso de Ribbond® como puente adhesivo ya que permite mejorar la estética y rehabilitar temporalmente los espacios desdentados causados por la ausencia de un incisivo, principalmente una vez terminado el tratamiento de ortodoncia y en espera de una rehabilitación definitiva, aún más cuando el paciente no ha terminado su crecimiento y desarrollo. En este artículo se presenta un caso clínico de un paciente con labio leporino y fisura velopalatina operado demostrativo de la técnica de rehabilitación con Ribbond®.

Today the increasing demand of aesthetic and minimally invasive procedures has led to a boom of the adhesive technique. Ribbond® is a polyethylene fiber that allows an efficient transfer of forces, is virtually foldable and is easily adapted to tooth morphology and dental arch contour. Among its main features we can find: Biocompatibility, inert, translucent and durable. In dentistry, different uses have been given to this fiber, whether as space maintainer, adhesive bridge, endodontic post and core, splinting, inlay type restorations and postorthodontic stabilization. In the case of cleft lip and palate patients the use of Ribbond® as an adhesive bridge has become relevant, as it improves aesthetics and temporarily rehabilitates the edentulous spaces caused by the absence of an incisor. It is used especially after completion of the orthodontic treatment and waiting for a final rehabilitation, even when the patient has not completed their growth and development. This article presents a clinical case of a patient with lip and cleft palate operated with the rehabilitation technique using Ribbond®.

O uso de implantes orbitários de polietileno granulado de ultra-alto peso molecular no reparo de cavidades anoftálmicas / The use of orbital ultra-high molecular weight granulated polyethylene implants in the anophthalmic socket repair

OBJETIVO: Alterações oculares, em especial a perda de volume nas cavidades evisceradas, promovem uma série de modificações ao paciente tanto funcional do órgão quanto psicológica e estética. Para tanto a procura de um material de baixo custo e com biocompatibilidade tem sido uma constante na literatura. Portanto, esse trabalho teve como objetivo testar experimentalmente implante de polietileno granulado de ultra-alto peso molecular, material de baixo custo, em órbitas de coelhos submetidos à evisceração cirúrgica em vários tempos experimentais, onde foram avaliados aspectos macroscópicos e microscópicose de toxicidade sistêmica do material. MÉTODOS: Para esse estudo foram utilizados coelhos Oryctolaguscuniculus submetidos à evisceração do globo ocular direito e posteriormente implantados com esfera de polietileno granulado de ultra-alto peso molecular e analisados por 15, 30, 90 e 180 dias pós-implante, com parâmetros macro, microscópios e bioquímicos. Os animais controles foram submetidos ao mesmo procedimento sem, entretanto a colocação do implante. RESULTADOS: Os resultados desse trabalho mostram que o material utilizado no implante de cavidade não apresenta alteração significativa nos parâmetros de peso e bioquímicos quando comparados ao grupo controle. O material implantado apresentou uma grande interação com o tecido do hospedeiro. CONCLUSÃO: Os resultados indicam que implante de polietileno granulado de alto peso molecular desenvolvido por uma indústria nacional tem alto potencial para se realizar testes em humanos.

OBJECTIVE: Ocular changes in special due to volume loss in eviscerated cavities promote several psychological aesthetic and functional alterations to patients. For this reason, searches aiming at finding a material of low cost and biocompatibility have been constantly carried out. Test experimentally the implants constituted of ultra-high molecular weight granular polyethylene oflow cost, in orbits of rabbits subjected to surgical evisceration in several experimental times, evaluating the macro and microscope aspects besides the systemic toxicity of the material. METHODS: In this study we eviscerated the right ocular globe of rabbits of the species Oryctolaguscuniculus, implanted posteriorly a sphere of granular polyethylene of ultrahigh molecular weight and analysed the effects through macro, micro and biochemical parameters during 15, 30, 90 and 180 days after implantation.The control group were submitted the same procedure without the implants. RESULTS: This paper shows that the material used in the cavity does not present significant alteration in the weight and in the biochemistry of the animal; a good assimilation (integration) of the material implanted by the tissue formed was observed inside the implant. CONCLUSION: The results indicate that ultra-high molecular weight granular polyethylene implant developed by a national industry presents excellent integration in the model used supporting further use in tests with humans.

Luxação traumática do bulbo ocular causada por acidente automobilístico / Traumatic eye luxation caused by automobilistic accident

Descreve-se um paciente com trauma ocular grave causada por acidente automobilístico que acarretou luxação total de bulbo ocular.

Description of a patient with grave ocular trauma caused by a traffic accident that it followed by total luxation of the eye.

Consideraciones sobre el desgaste del polietileno en la artroplastia total de cadera / Considerations on polyethylene wear in jip total arthroplasty

INTRODUCCION: El desgaste del polietileno ha sido un problema desde la introducción de la artroplastia total de baja fricción y continua siéndolo en la actualidad en lo que influyen múltiples condiciones. OBJETIVO: Describir las consideraciones técnicas necesarias en la artroplastia total de cadera en aras de garantizar la mayor durabilidad de sus componentes. MÉTODOS: Se realiza una revisión de la literatura publicada al respecto tomándose en cuenta las variables que afectan el desgaste del polietileno así como las maniobras técnicas que pueden ser realizadas por el cirujano en aras de optimizar la durabilidad de los componentes protésicos. RESULTADOS: La inclinación de la cúpula mayor de 45º está directamente relacionada con el desgaste del polietileno. La restauración del centro de rotación de la cadera con el centro de rotación de la cúpula ha sido un importante objetivo en la técnica de cementación del acetábulo debido a reportes de su relación con el desgaste. La cobertura por el hueso es importante para evitar el pinzamiento del cuello de metal contra el polietileno o el anillo de metal de la cúpula. CONCLUSIÓN: El cirujano puede cambiar el centro de rotación del acetábulo para obtener una óptima inclinación y cobertura de forma segura sin que implique un incremento de la incidencia del efecto adverso de desgaste

INTRODUCTION: The polyethylene wear has been a problem from the introduction of low fraction total arthroplasty until nowadays where influencing many conditions. OBJECTIVE: To describe the technical conditions needed in the total hip arthroplasty to guarantee a greater durability of its components. METHODS: Literature published on this subject is reviewed taking into account the variables affecting the polyethylene wear as well as the possible technical manoeuvres carried out by surgeon to optimize the durability of prosthetic components. RESULTS: The 45º slope of major cupula is directly related to polyethylene wear. Restoration of the hip rotation center with the cupula rotation center has been a significant objective in acetabulum cementation due to reports of its relation to wear. The bone coverage is important to avoid the metal neck clamping against the polyethylene or the metal ring of cupula. CONCLUSION: The surgeon may to change the acetabulum rotation center to achieve an optimal and safe slope and coverage without an increase of incidence of wear adverse effect

Reconstrução da estrutura facial por biomateriais: revisão de literatura / Facial structure reconstruction by biomaterials: literature review

A região facial apresenta um desafio único para o implante de biomateriais, porque o esforço de tração dos músculos dessa região produz carregamento variável em diferentes regiões. Este trabalho apresenta as causas do amplo uso de biomateriais na reconstrução facial, descrevendo as características, as vantagens e as desvantagens de cada tipo específico de material para cada região da face.

The facial region presents an unique challenge for implantable biomaterials because the pull of the facial muscles produces variable loading in different regions. This work presents the reasons of the wide use of biomaterial in facial reconstruction, pointing out the advantages and the disadvantages of each specific material type for each face region.

Fixed partial dentures in an up to 8-year follow-up

Information on the longevity of fiber-reinforced composite fixed partial dentures (inlay FPDs) should be considered in the selection of materials, operative techniques and patient instructions related to prognosis and long-term cost-effectiveness. OBJECTIVE: This study evaluated the long-term survival of fiber-reinforced, adhesively-bonded composite prostheses placed in posterior teeth. Materials and Methods: Twenty-one patients that received adhesively bonded polyethylene inlay FPDs in posterior teeth were selected from a private practice dental office and invited to evaluation. Of the eligible 21 patients, 13 (mean age 50.3 ± 11.5 years) agreed to be enrolled as participants, providing 22 restorations, as several subjects presented more than one inlay FPD. One dentist placed all inlay FPDs using Ribbond as reinforcement and Tetric Ceram/Durafil or Charisma/Renamel composite combinations, according to manufacturer's instructions. Two independent calibrated operators performed the evaluation, using modified USPHS criteria. Survival functions of restorations were analyzed with Kaplan-Meier and Log Rank test (α = 0.05). RESULTS: The majority of restorations received A or B scores. Four (18.2 percent) inlay FPDs fractured among the 22 evaluated. The mean estimate survival rate was 7 years (95 percent CI: 5.9 to 8.1), and the overall percentage of survival was 81.8 percent. There were no significant differences (p>0.05) between composite combinations or tooth location considering all clinical aspects evaluated and survival functions. CONCLUSION: Posterior fiber-reinforced fixed partial dentures exhibited acceptable clinical performance after a period up to 8 years.

In vitro studies of multiwalled carbon nanotube/ultrahigh molecular weight polyethylene nanocomposites with osteoblast-like MG63 cells

Carbon nanotubes are highly versatile materials; new applications using them are continuously being developed. Special attention is being dedicated to the possible use of multiwalled carbon nanotubes in biomaterials contacting with bone. However, carbon nanotubes are also controversial in regards to effects exerted on living organisms. Carbon nanotubes can be used to improve the tribological properties of polymer/composite materials. Ultrahigh molecular weight polyethylene (UHMWPE) is a polymer widely used in orthopedic applications that imply wear and particle generation. We describe here the response of human osteoblast-like MG63 cells after 6 days of culture in contact with artificially generated particles from both UHMWPE polymer and multiwalled carbon nanotubes (MWCNT)/UHMWPE nanocomposites. This novel composite has superior wear behavior, having thus the potential to reduce the number of revision hip arthroplasty surgeries required by wear failure of acetabular cups and diminish particle-induced osteolysis. The results of an in vitro study of viability and proliferation and interleukin-6 (IL-6) production suggest good cytocompatibility, similar to that of conventional UHMWPE (WST-1 assay results are reported as percentage of control ± SD: UHMWPE = 96.19 ± 7.92, MWCNT/UHMWPE = 97.92 ± 8.29 percent; total protein: control = 139.73 ± 10.78, UHMWPE = 137.07 ± 6.17, MWCNT/UHMWPE = 163.29 ± 11.81 µg/mL; IL-6: control = 90.93 ± 10.30, UHMWPE = 92.52 ± 11.02, MWCNT/UHMWPE = 108.99 ± 9.90 pg/mL). Standard cell culture conditions were considered as control. These results, especially the absence of significant elevation in the osteolysis inductor IL-6 values, reinforce the potential of this superior wear-resistant composite for future orthopedic applications, when compared to traditional UHMWPE.

Endodontic and prosthetic treatment of teeth with periapical lesions in a 16-year-old-girl

This paper reports the nonsurgical endodontic therapy using calcium hydroxide intracanal dressing and prosthetic treatment of 9 teeth with periapical lesions in a 16-year-old female patient. The periodontal treatment plan included oral hygiene instructions, mechanical debridement and gingivectomy in the maxillary incisors to improve gingival contouring. Root canal treatment was indicated for teeth 11-13, 21, 22, 42-45. After successive changes of a calcium hydroxide intracanal dressing during 6 weeks, the size of the periapical radiolucencies decreased and lesion remission occurred after root canal obturation. The endodontically treated teeth received a bondable polyethylene reinforcement fiber (Ribbond) in the prepared canal space and crown buildup was done with composite resin. Prosthetic rehabilitation was planned with single-unit metal-ceramic crowns and fixed partial dentures. Clinical and radiographic evaluation after 6 months showed successful results. The outcomes of this case showed that chronic periapical lesions can respond favorably to nonsurgical endodontic treatment in adolescent patients and that, with proper indication, polyethylene fibers can provide an effective conservative and esthetic option for reinforcing endodontically treated teeth undergoing prosthetic rehabilitation.

Restoration of crown fractures with a fiber post, polyethylene fiber and composite resin / Restauração de fraturas coronárias com pinos de fibra, de polietileno e de resina composta: técnica restauradora combinada com dois relatos de caso

OBJECTIVE: To describe the treatment of two patients who had horizontal crown fractured maxillary incisors a few years after endodontic treatment. METHOD: The 23 and 19-year-old male patients presented to Atatürk University Dentistry Faculty with complex crown fractures. The treatment includeda glass fiber reinforced root canal post, a fiber ribbon core and restoration with a universal resin composite. RESULTS AND CONCLUSION: The one-year follow-up examinations showed thatthe restorations were still in place and successful.

OBJETIVO: Descrever o tratamento de dois pacientes com fraturas horizontais de coroas de incisivos superiores, alguns anos após tratamento endodôntico. MÉTODO: Os pacientes, ambos do sexo masculino, com 23 e 19 anos de idade, apresentaram-se na Faculdade de Odontologia da Universidade Ataturk com fraturas coronárias complexas de incisivos superiores. O tratamento consistiu de utilização de pinos intracanais reforçados com fibra de vidro, tiras de fibra de vidro e restauração com uma resina composta universal. RESULTADOS E CONCLUSÃO: Oacompanhamento do paciente por um ano mostrou o sucesso do tratamento.

Estudo de ação da saliva nas propriedades mecânicas de protetores bucais para esporte* / Study on the effect of saliva on the effect of saliva on the mechanical properties of mouth protectors for sports

Introdução - A eficiência e a durabilidade de protetores bucais para esporte dependem diretamente da forma com que são usados, pois sempre se apresentam em condições básicas de presença ou ausência de saliva. Para observar se essa condição de uso interfere em suas propriedades mecânicas este trabalho observa através de modelo experimental de arcos dentais obtidos em epóxi, acoplados a uma máquina universal de ensaios Kratos programada para movimento de compressão, o comportamento mecânico de protetores bucais para esporte, confeccionados em copolímero de etileno e acetato de vinila - EVA, posicionados no arco superior. Material e Métodos - Foram formados dois grupos de estudo: protetores bucais secos e protetores bucais saturados em saliva artificial, sendo estes últimos obtidos através de análise de saturação com o auxílio de balança analítica para observação de ganho de massa. As propriedades mecânicas observadas foram força máxima e energia absorvida. Resultados - Os resultados foram submetidos a análise estatística t-student (p < 0,05). Observou-se que no grupo dos protetores bucais saturados com saliva houve redução da força máxima (p = 0,00) devido a plastificação do material, responsável pela redução das forças intermoleculares ocasionando maior deformabilidade do protetor atestado pelo aumento da energia absorvida (p = 0,05) quando comparado ao grupo dos protetores secos. Conclusão - Conclui-se que a presença da saliva altera o comportamento mecânico do protetor bucal confeccionado em EVA tornando-o mais dúctil, portanto diminuindo a probabilidade de fraturas dentais e/ou lesões em tecidos circunvizinhos

Rotura aguda del tendon de Aquiles. Comparacion biomecanica de tres tecnicas de sutura con polietileno trenzado combinado en modelos cadavericos / Achilles tendon repair. Biomechanical differences resulting from the combination of braided polyblend polyethylene and 3 types of suturing techniques in a human cadaver model

Introducción: La rotura del tendón de Aquiles es una patología frecuente. Si bien el tratamiento quirúrgico es el de elección, existe controversia sobre el tipo de sutura y la técnica reparadora que se debe realizar para permitir la pronta rehabilitación del paciente. El objetivo del presente estudio es analizar el comportamiento de diferentes técnicas de suturas de aplicación habitual en la reparación del tendón de Aquiles, asociadas con el uso de un hilo de polietileno trenzado combinado con poliéster al ser sometidas a tensión, y determinar cuál es la que mejor permite una rehabilitación más rápida con menor riesgo.Materiales y métodos: Se analizó el comportamientobiomecánico y de resistencia de la sutura de diferentes reparaciones tendinosas de uso corriente (punto de Kessler modificado, punto de Krackow y punto de Bunnell),combinado con un hilo de polietileno trenzado y fibras depoliéster. Se utilizaron 15 cadáveres frescos humanos. Lareparación fue sometida a diferentes cargas de fuerzasténsiles secuenciales progresivas medidas en newton (N).En cada fuerza la diastasis tendinosa y/o la rotura del hilo producida fueron medidas por tres observadores independientes. Los resultados se analizaron mediante pruebas estadísticas de probabilidad y porcentajes.Resultados: La comparación a tensiones de 75 N arrojólos siguientes resultados: Bunnell frente a Krackow: t =2,02 p: 0.078; Bunnell frente a Kessler: t = -0.775 p:0,461; y Kessler frente a Krackow: t = 1,71 p: 0,12. A tensiones de 135 N, la combinación del material con la sutura de Bunnell presentó diastasis aceptables (8 mm) y bajo índice de falla del hilo (20 por ciento). La sutura de Krackow tuvo una elongación inaceptable a 135 N: 16,5 mm (DE: 6,2) y la sutura de Kessler presentó poca diastasis (3,66 mm), pero alto índice de rotura (80 por ciento). Conclusiones: La combinación de material de polietileno trenzado y fibras de poliéster, con la técnica de Krackow, demostró tener alto índice de elongación y...

Artificial eye amplitudes and characteristics in enucleated socket with porous polyethylene spherical and quad-motility implant

PURPOSE: To compare artificial eye amplitudes in enucleated socket with porous polyethylene either spherical or quad-motility implant and study the characteristics of artificial eyes fit with the two orbital implants. METHODS: A total of 21 patients were prospectively studied who underwent enucleation because of an intraocular melanoma and the randomization defined a porous polyethylene either spherical or quad-motility orbital implant. Measurements of the amplitude of the artificial eye were obtained with prism and digital photos. The software Scion Image analyzed the digital photos (www.scioncorp.com) and the quantitative data were allocated to groups. The measurements (height, length, thickness) and weight of the 21 artificial eyes were analyzed. Student's t-test was performed to determine the significance of difference between groups (p<0.05). RESULTS: There was no statistically significant difference of the artificial eye amplitude analyzed by means of prisms between both orbital implants (p>0.05 for all directions). On analyzing the digital photos, the artificial eye with spherical implant showed higher artificial eye amplitude downward (p=0.009) among patients older than 55 years old, rightward (p=0.036) and downward (p=0.008) among the 9 patients with enucleated right eye. Height and length were similar in the 21 artificial eyes but those artificial eyes fit with quad-motility orbital implants were statistically significant thicker (p<0.001) and heavier (p=0.001). CONCLUSIONS: The similar amplitude of movement of artificial eyes was observed with both spherical and quad-motility orbital implants. Artificial eyes fit with quad-motility orbital implant are significantly thicker and heavier than those fit with spherical orbital implant.

OBJETIVOS: Comparar a amplitude de movimento da prótese ocular em cavidade enucleada e com implante orbitário esférico e "quad-motility" e estudar as características das próteses oculares adaptadas com os dois modelos de implantes orbitários. MÉTODOS: Vinte e um pacientes foram prospectivamente estudados após a enucleação devido a melanoma intra-ocular e cuja randomização definiu o implante orbitário de polietileno poroso nos modelos esférico e "quad-motility". Medidas da amplitude da prótese ocular foram obtidas com prisma e fotografia digital. O programa Scion Image analisou as fotos digitais (www.scioncorp.com) e os resultados foram distribuídos por grupos. As medidas (altura, comprimento, espessura) e o peso das 21 próteses também foram analisados. O teste de t foi realizado para determinar a significância da diferença entre os grupos (p<0,05). RESULTADOS: Não houve diferença significante na amplitude do movimento das próteses oculares, analisada com a interposição do prisma em ambos implantes orbitários (p>0,05 em todas as posições). Ao analisar a fotografia digital, as próteses adaptadas com implante esférico apresentaram maior amplitude de movimento na infraversão (p=0,009) para pacientes acima de 55 anos, infraversão (p=0,008) e dextroversão (p=0,036) nos nove pacientes com o olho direito enucleado. Altura e comprimento foram similares nas 21 próteses oculares. Próteses oculares adaptadas com implante "quad-motility" foram significantemente mais espessas (p<0,001) e pesadas (p=0,001). CONCLUSÕES: A amplitude de movimento das próteses oculares foi similar nos implantes esférico e "quad-motility". As próteses oculares adaptadas com implante "quad-motility" são significantemente mais espessas e pesadas do que as adaptadas com implante esférico.

Estudo da energia absorvida em protetores bucais confeccionados em copolímero de etileno e acetato de vinila: modelo experimental de arcos dentais obtidos em epóxi / Study of the obsorbed energy in mouth protectors made of ethylene and vinila acetate copolymer: experimental model of dental arches obtained in epoxy

Um modelo experimental de arco dentário, moldado em epóxi, foi utilizado para estudar o comportamento mecânico do copolímero de etileno e acetato de vinila (EVA), na forma de placa plana e protetor bucal. O modelo experimental foi investigado, usando-se um sistema configurado em duas formas diferentes: suporte+arco+placa plana e suporte+arco+protetor bucal. A propriedade mecânica do EVA, ao esforço compressivo, avaliada nas duas configurações (suporte+arco+placa e suporte+arco+protetor), foi a energia aparente absorvida (J.mm-¹). Os efeitos das variáveis "espessura", "temperatura" e "presença ou ausência da saliva artificial" foram modelados, matematicamente, usando-se as propriedades mecânicas do EVA ao esforço compressivo, como parâmetros de resposta. Os polinômios ortogonais foram ajustados em função das variáveis e de suas interações significantes, fixando-se o nível de significância igual ou menor de 0,05 ou 5%.

Uso de 2-octil-cianoacrilato na reconstrução da cavidade anoftálmica de coelhos / 2-octyl-cyanoacrylate in rabbit anophthalmic cavity reconstruction

OBJETIVO: Avaliar a ligação entre músculos oculares extrínsecos e esferas de polietileno poroso usando um bioadesivo. MÉTODOS: Estudo experimental envolvendo 8 coelhos albinos submetidos a enucleação do olho direto com colocação de implante esférico de polietileno poroso de 12 mm de diâmetro unido aos músculos oculares extrínsecos por meio do bioadesivo 2-octil-cianoacrilato. Noventa dias após a cirurgia os animais foram sacrificados e o conteúdo orbitário removido. Em 4 animais foi realizado estudo biomecânico, avaliando-se a força de ruptura entre a musculatura e a esfera (grupo implante) e entre a musculatura e a esclera nos olhos contralaterais (grupo controle). Nos outros 4 animais foi realizada análise histológica. RESULTADO: A avaliação biomecânica revelou que a força de ruptura entre esfera-músculo e esclera-músculo foram semelhantes quando se usa o adesivo de cianoacrilato. O exame histológico mostrou reação fibrovascular no local da adesão entre a musculatura e a esfera, sem efeitos deletérios aos tecidos. Ao redor dos implantes foi possível observar pseudocápsula e no interior, neovasos e tecido fibrovascular preenchendo os espaços entre os grânulos do polietileno. CONCLUSÃO: O adesivo 2-octil-cianoacrilato mantém boa força de adesão na união entre os músculos e as esferas de polietileno poroso, com redução do tempo cirúrgico e sem efeitos deletérios aos tecidos orbitais. Desta forma, deve-se considerar o uso do bioadesivo na reconstrução da cavidade anoftálmica.

PURPOSE: To evaluate fixation by a bioadhesive of the external ocular muscles to the porous polyethylene spheres. METHODS: An experimental study was performed using eight white rabbits that underwent right eye enucleation with placement of 12 mm spheres of porous polyethylene. The rectus muscles (superior and inferior) were attached to the implant with a bioadhesive (2-octyl-cyanoacrylate) applied to the inferior side of the external muscles. Ninety days after surgery the orbital content was removed and 4 animals were submitted to a tensile strength test of the muscle-sphere attachment and the other 4 to histological evaluation. RESULTS: The tensile strength test showed that the rupture force was similar between the muscle and porous polyethylene sphere bond attachment and normal external ocular muscles. The histologic evaluation showed fibrous tissue reaction and muscle-sphere attachment with no deleterious effects to the tissues; a capsule formation around the spheres and new vessels inside the implant were also observed. CONCLUSION: 2-octyl-cyanoacrylate provides strength adhesion between muscles and spheres, with surgery time reduction and does not provoke deleterious effects on the orbital tissues. Thus, the bioadhesive might be a good choice for use in the anophthalmic cavity reconstruction.