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The design of scaffolds to reach similar three-dimensional structures mimicking the natural and fibrous environment of some cells is a challenge for tissue engineering, and 3D-printing and electrospinning highlights from other techniques in the production of scaffolds. The former is a well-known additive manufacturing technique devoted to the production of custom-made structures with mechanical properties similar to tissues and bones found in the human body, but lacks the resolution to produce small and interconnected structures. The latter is a well-studied technique to produce materials possessing a fibrillar structure, having the advantage of producing materials with tuned composition compared with a 3D-print. Taking the advantage that commercial 3D-printers work with polylactide (PLA) based filaments, a biocompatible and biodegradable polymer, in this work we produce PLA-based composites by blending materials obtained by 3D-printing and electrospinning. Porous PLA fibers have been obtained by the electrospinning of recovered PLA from 3D-printer filaments, tuning the mechanical properties by blending PLA with small amounts of polyethylene glycol and hydroxyapatite. A composite has been obtained by blending two layers of 3D-printed pieces with a central mat of PLA fibers. The composite presented a reduced storage modulus as compared with a single 3D-print piece and possessing similar mechanical properties to bone tissues. Furthermore, the biocompatibility of the composites is assessed by a simulated body fluid assay and by culturing composites with 3T3 fibroblasts. We observed that all these composites induce the growing and attaching of fibroblast over the surface of a 3D-printed layer and in the fibrous layer, showing the potential of commercial 3D-printers and filaments to produce scaffolds to be used in bone tissue engineering.

RESUMEN: El objetivo de este estudio fue determinar el riesgo de caries en la población infantil entre 7 y 34 meses, usuarios de un centro de atención primaria de salud en la ciudad de Osorno, ingresados al programa de Población en Control con Enfoque de Riesgo Odontológico (CERO) durante el año 2017. Expresándolo en alto o bajo riesgo. Se realizó un estudio observacional descriptivo, tomando una muestra de 135 pacientes, con edades dentro del rango en estudio, inscritos en el centro de salud e ingresados al programa. Se utilizaron las pautas diseñadas por el Ministerio de Salud e incluidas en el programa CERO, aplicándolas en una sesión, junto al examen clínico para determinar el nivel de riesgo de cada individuo. Posteriormente se sometieron los datos a análisis de estadística descriptiva. El 59 % de la población entre 7-34 meses tiene un riesgo de caries alto. El grupo con mayor riesgo es el de 12-23 meses con un 70 %. Los hombres tienen un 59 % de riesgo alto y las mujeres un 58 %. Al analizar en detalle cada variable, el "cepillado antes de dormir" fue el que con mayor frecuencia se encontraba en alto riesgo, con un 60 %, seguido del "momento de ingesta de alimentos azucarados" y el "uso de pasta con flúor", con un 56 % y 53 %, respectivamente.