Evaluación del efecto del rofecoxib en los cambios dentino-pulpares, el movimiento dental y la inhibición de la reabsorción radicular durante la aplicación de fuerzas ortodóncicas intrusivas

ABSTRACT: Root resorption associated to dental movement is an undesired side effect during orthodontic therapy. The purpose of this study was to identify the changes in the pulp-dentine organ, the degree of external root resorption, and the amount of dental movement in patients under Rofecoxib treatment, during the application of 2 ounce-intrusive orthodontic forces. The sample consisted of 6 subjects (12 teeth) on whom 8 teeth were evaluated as the experimental group (Rofecoxib) and 4 teeth as the control group (placebo). A fixed device (transpalatal bar) was used and a bracket was attached to the middle third of the buccal surface of the first upper premolar. On each segment a TMA wire with intrusive bends was set and activated every 6 weeks. The protocol of drug and placebo intake was determined by taking into account the stabilization of their concentration after regular administration. As part of the treatment, the premolars were extracted and prepared for histological examination. These cuts were dyed with Hematoxilin-Eosin colorants and Masson’s Trichoromic in order to observe them under the light microscope. The histological cuts showed more morphological changes at the odontoblastic layer, with increase in the number of collagen fibers and angiogenesis for the experimental group. In contrast, the control group presented more root damage than the experimental group. The range of dental movement under Rofecoxib was greater than the range under placebo after measuring the degree of dental movement. The rofecoxib showed to be effective in the inhibition of the RRE, compared with a medication placebo in this sample. With the current limitations to the rofecoxib use, one can say that the preferential inhibitors of the COX-2 present a better control that the specific inhibitors of the COX-2 in the dentinopulpar deleterious changes that are presented after the intrusive movement.RESUMEN: La reabsorción radicular asociada al movimiento dental es un efecto indeseado durante la terapia ortodóncica. El propósito de este estudio fue el de identificar los cambios dentinopulpares, el grado de reabsorción radicular externa (RRE) y la cantidad de movimiento dental en pacientes medicados con rofecoxib durante la aplicación de fuerzas ortodóncicas intrusivas de 2 onzas. La muestra la constituyeron 6 sujetos (12 dientes) en quienes se evaluaron 8 dientes para el grupo experimental (rofecoxib) y 4 dientes para el grupo control (placebo). Se utilizó un aparato fijo tipo barra transpalatina y un bracket adherido a tercio medio de la cara vestibular de los primeros bicúspides superiores, en cada segmento se instaló un alambre TMA con dobleces intrusivos que fueron activados cada seis semanas. El protocolo de administración del medicamento y del placebo se planteó teniendo en cuenta la estabilización de su concentración tras su administración en forma regular. Como parte del tratamiento los premolares fueron extraídos y se realizaron los cortes respectivos, se utilizó coloración de hematoxilina-eosina y tricrómica de Masson para observar los cortes al microscopio de luz. En los cortes histológicos se observó en la capa odontoblástica mayores cambios morfológicos, aumento de las fibras colágenas y angiogénesis en el grupo experimental. Se encontró que el grupo control presentó mayor cantidad de lesiones radiculares que el grupo experimental. Al medir la cantidad de movimiento dental, se observó que los rangos de movimiento bajo el rofecoxib fueron mayores que con el placebo. El rofecoxib mostró ser eficaz en la inhibición de la RRE, comparado con un medicamento placebo en esta muestra. Con las actuales limitaciones del uso del rofecoxib, se puede decir que los inhibidores preferenciales de la ciclooxigenasa-2 (COX -2) presentan mejor control que los inhibidores específicos de la COX-2 en los cambios dentinopulpares deletéreos que se presentan luego del movimiento intrusivo

Libro de Proyectos Finales 2021 primer semestre

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The database of the PREDICTS (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems) project

The PREDICTS project—Projecting Responses of Ecological Diversity In Changing Terrestrial Systems (www.predicts.org.uk)—has collated from published studies a large, reasonably representative database of comparable samples of biodiversity from multiple sites that differ in the nature or intensity of human impacts relating to land use. We have used this evidence base to develop global and regional statistical models of how local biodiversity responds to these measures. We describe and make freely available this 2016 release of the database, containing more than 3.2 million records sampled at over 26,000 locations and representing over 47,000 species. We outline how the database can help in answering a range of questions in ecology and conservation biology. To our knowledge, this is the largest and most geographically and taxonomically representative database of spatial comparisons of biodiversity that has been collated to date; it will be useful to researchers and international efforts wishing to model and understand the global status of biodiversity