Conformation Effect on the Mechanical and Microbiological Behavior of Invisible Orthodontic Aligners.

Invisible orthodontic aligners are having a great impact on tooth movement in an aesthetic and effective way. Different techniques, models, and clinical aspects have been studied for their proper use. However, the aim of this research has been to determine the effect of the shaping process on mechanical properties and their bacterial behavior. For this study, 40 original polyurethane plates and 40 identical models, obtained by hot forming the original plates, were used. The static tensile mechanical properties were studied with a Zwick testing machine using testing speeds of 5 mm/min at a temperature of 37 °C. The original plate and the aligner have been studied with a creep test by subjecting the samples to a constant tension of 30 N, and determining the elongation using a long-distance, high-resolution microscope at different time periods between 1 and 720 h. Studies of water absorption has been realized with artificial saliva for 5 h. Bacterial cultures of Streptococcus oralis and Actinomyces viscosus strains were grown on the original plates and on new and used models, to determine the proliferation of each bacterium through metabolic activity, colony-forming units, and LIVE/DEAD assays. The mechanical results showed an increase in the strength of the inserts with respect to the models obtained from 3.44 to 3.95 MPa in the elastic limit and a lower deformation capacity. It has been proven that the transition zone in the creep curves lasts longer in the original plate, producing the rapid increase in deformation at a shorter time (400 h) in the aligner. Therefore, the shaping process reduces the time of dental correction exerted by the aligner. The results of the bacterial culture assays show an increase in the number of bacterial colonies when the aligners have been used and when the polyurethane is conformed due to the internal energy of the model, with respect to the original polyurethane. It has been observed that between the original plate and the aligner there are no statistically significant differences in water absorption and therefore the forming process does not affect water absorption. A slight increase in water absorption can be observed, but after five hours of exposure, the increase is very small.

Bacteriostatic Poly Ethylene Glycol Plasma Coatings for Orthodontic Titanium Mini-Implants.

Titanium mini-implants are used as anchorage for orthodontic tooth movements. However, these implants present problems due to the infection of surrounding tissues. The aim of this work was to obtain a polyethylene glycol (PEG) layer by plasma in order to achieve a bacteriostatic surface. Titanium surfaces were activated by argon plasma and, after, by PEG plasma with different powers (100, 150 and 200 W) for 30 and 60 min. The roughness was determined by white light interferometer microscopy and the wettability was determined by the contact angle technique. Surface chemical compositions were characterized by X-ray photoelectron spectroscopy (XPS) and cytocompatibility and cell adhesion studies were performed with fibroblast (hFFs) and osteoblast (SAOS-2) cells. Bacterial cultures with Spectrococcus Sanguinis and Lactobacillus Salivarius were performed, and bacterial colonization was determined. The results showed that plasma treatments do not affect the roughness. Plasma makes the surfaces more hydrophilic by decreasing the contact angles from 64.2° for titanium to 5.2° for argon-activated titanium, with values ranging from 12° to 25° for the different PEG treatments. The plasma has two effects: the cleaning of the surface and the formation of the PEG layer. The biocompatibility results were, for all cases, higher than 80%. The polymerization treatment with PEG reduced the adhesion of hFFs from 7000 to 6000 and, for SAOS-2, from 14,000 to 6500, for pure titanium and those treated with PEG, respectively. Bacterial adhesion was also reduced from 600 to 300 CFU/mm2 for Spetrococcuns Sanguinis and from 10,000 to 900 CFU/mm2 for Lactobacillus Salivarius. The best bacteriostatic treatment corresponded to PEG at 100 W and 30 s. As a consequence, the PEG coating would significantly prevent the formation of bacterial biofilm on the surface of titanium mini-implants.

Manejo diagnóstico y terapéutico actual de la fractura de los primeros pasos / Current diagnosis and management of toddler's fracture

INTRODUCCIÓN: La fractura de los primeros pasos o fractura de toddler es una fractura espiroidea de tibia propia de la primera infancia. El objetivo es analizar su incidencia y el manejo diagnóstico y terapéutico actual. PACIENTES Y MÉTODOS: Estudio descriptivo retrospectivo de los pacientes de 0 a 3 años diagnosticados en un hospital terciario entre los años 2013 y 2017. RESULTADOS: Registrados 53 pacientes (10,6 casos/año), con una mediana de edad de 2 años y ligero predominio masculino. La radiografía inicial resultó normal en el 24,5%. Con la aproximación inicial, el 69,8% de los pacientes se diagnosticaron de fractura, el 11,3% de sospecha de fractura y el 18,9% de contusión. El 22% precisaron prueba de control; 10 radiografía (patológica 90%) y 5 ecografía (patológica 80%, 3 de ellos con radiografía inicial normal). El 80,8% de los pacientes se inmovilizaron con férula frente al 19,2% en los que se realizó inmovilización flexible o no inmovilización. Se encontraron complicaciones en el 21,4% de los pacientes inmovilizados con férula, fundamentalmente úlceras por presión (19%), que fueron más frecuentes en este grupo que en los no inmovilizados (21,4 vs. 0%; p = 0,006), sin diferencias significativas en cuanto a tiempo hasta carga. CONCLUSIONES: La radiografía simple tiene una sensibilidad limitada para el diagnóstico de la fractura de los primeros pasos. En el grupo de pacientes con radiografía normal el uso de ecografía puede contribuir al diagnóstico y a evitar radiación adicional. Aunque el tratamiento más común de esta fractura sigue siendo la inmovilización con férula, la alternativa sin inmovilización rígida no parece obtener peores resultados, incluso parece presentar menor morbilidad asociada al tratamiento

INTRODUCTION: Toddler's fracture is an accidental spiral tibial fracture, characteristic of the early childhood. The objective of this study is to determine the incidence and current diagnosis and management of this disorder. PATIENTS AND METHODS: A retrospective study was conducted on a sample of patients aged 0-3 years diagnosed with a toddler's fracture in a tertiary hospital between years 2013 and 2017. RESULTS: A total of 53 patients were registered (10.6 cases per year). The median age was 2 years, with a slight male predominance. The initial radiograph was normal in 24.5% of patients. With the initial approach, 69.8% of patients were diagnosed with fracture, 11.3% with suspected fracture, and 18.9% with contusion. A follow-up was required in 22% required a control test, using radiographs in 10 patients (pathological 90%), and ultrasound in 5 (pathological 80%, 3 of them with normal initial radiography). The large majority (80.8%) of the patients were immobilised with a cast, while flexible immobilisation or non-immobilisation was used in 19.2%. Complications were found in a 21.4% of patients immobilised with splint, mainly skin injuries (19%). These were more frequent in this group than in those that were not immobilised (21.4% vs. 0%, P = .006); with no significant differences in time to weight-bearing. CONCLUSIONS: Radiography has a limited sensitivity for the diagnosis of toddler's fracture. In the group of patients with normal radiography, the use of ultrasound can be helpful to the diagnosis and avoid additional radiation. Even though the most common treatment continues to be immobilisation with a splint, the alternative without rigid immobilisation does not seem to give worse results, even with lower morbidity associated with the treatment

[Current diagnosis and management of toddler's fracture]. / Manejo diagnóstico y terapéutico actual de la fractura de los primeros pasos.

INTRODUCTION: Toddler's fracture is an accidental spiral tibial fracture, characteristic of the early childhood. The objective of this study is to determine the incidence and current diagnosis and management of this disorder. PATIENTS AND METHODS: A retrospective study was conducted on a sample of patients aged 0-3 years diagnosed with a toddler's fracture in a tertiary hospital between years 2013 and 2017. RESULTS: A total of 53 patients were registered (10.6 cases per year). The median age was 2 years, with a slight male predominance. The initial radiograph was normal in 24.5% of patients. With the initial approach, 69.8% of patients were diagnosed with fracture, 11.3% with suspected fracture, and 18.9% with contusion. A follow-up was required in 22% required a control test, using radiographs in 10 patients (pathological 90%), and ultrasound in 5 (pathological 80%, 3 of them with normal initial radiography). The large majority (80.8%) of the patients were immobilised with a cast, while flexible immobilisation or non-immobilisation was used in 19.2%. Complications were found in a 21.4% of patients immobilised with splint, mainly skin injuries (19%). These were more frequent in this group than in those that were not immobilised (21.4% vs. 0%, P=.006); with no significant differences in time to weight-bearing. CONCLUSIONS: Radiography has a limited sensitivity for the diagnosis of toddler's fracture. In the group of patients with normal radiography, the use of ultrasound can be helpful to the diagnosis and avoid additional radiation. Even though the most common treatment continues to be immobilisation with a splint, the alternative without rigid immobilisation does not seem to give worse results, even with lower morbidity associated with the treatment.

Elaboración de un índice objetivo de selección de pacientes subsidiarios de prótesis articular de rodilla / Total knee prosthesis. Development of an objective selection tool for patients

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Autotrasplante de progenitores hematopoyéticos en una paciente con artritis reumatoide / Autologous stem cell transplantation in a patient with rheumatoid arthritis

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Evolución clínica y angiográfica al año de pacientes con infarto agudo de miocardio tratados con stent primario / One-year clinical and angiographic follow-up after primary stenting

Introducción y objetivos. En la angioplastia primaria, la reoclusión o reestenosis de la arteria responsable del infarto es frecuente. El stent podría mejorar los resultados de la angioplastia y la evolución a largo plazo de estos pacientes. Presentamos la evolución clínica y angiográfica de un grupo de pacientes con infarto agudo de miocardio tratados con stent primario. Pacientes y métodos. Se ha realizado seguimiento durante un año de 74 pacientes consecutivos con infarto agudo de miocardio tratado con angioplastia primaria e implante de stent. En el 91 por ciento de los pacientes se realizó un control angiográfico a partir del sexto mes para evaluar el grado de reestenosis y la tasa de reoclusiones de la arteria responsable. Resultados. Hubo 8 muertes intrahospitalarias y tres durante el año de seguimiento (mortalidad total de 14,8 por ciento) y un reinfarto no fatal (1,5 por ciento). La recurrencia acumulada de isquemia fue del 6 por ciento al tercer mes y del 15 por ciento al sexto mes, sin incremento al año de seguimiento. En 7 pacientes se realizó una nueva angioplastia y tres fueron revascularizados quirúrgicamente. El 80 por ciento de los enfermos que fueron dados de alta estaban libres de eventos al año de seguimiento. En el control angiográfico sólo un paciente presentó oclusión de la arteria responsable del infarto, y la tasa de reestenosis fue del 27 por ciento. Conclusiones. Estos resultados ponen de manifiesto que el stent puede ser utilizado de manera eficaz durante la angioplastia primaria en pacientes no seleccionados con baja incidencia a largo plazo de episodios adversos y una reducida tasa de reestenosis (AU)