Actividad antimicrobiana de adhesivo ortodóntico con nanopartículas de plata sobre Streptococcus mutans

espanolLa aparatologia fija usada en ortodoncia dificulta una adecuada higiene bucal, en estas condiciones el desarrollo de lesiones cariosas puede ser una complicacion, uno de los principales agentes etiologicos involucrados es Streptococcus mutans. La nanotecnologia con plata tiene una aplicacion preventiva importante en biomateriales dentales. Objetivo: Se determino la actividad antimicrobiana sobre Streptococcus mutans de nanoparticulas de plata (AgNPs) incluidas en adhesivos ortodonticos a diferentes concentraciones. Materiales y metodos: En 20 cajas Petri con Streptococcus mutans inoculada en agar Muller-Hinton suplementado con 5% de sangre, se colocaron 6 discos de papel, 4 embe-bidos con AgNPs incluidas en un adhesivo ortodontico a concentraciones de 25, 75, 125 y 175 ppm, y 2 discos controles con clorhexidina al 0.12% y agua destilada. Se determino la capacidad antimicrobiana en funcion de promedios de halos de inhibicion a las 48 horas de incubacion, en comparacion con la escala de Duraffourd y la clorhexidina 0.12%. Resultados: A 25 ppm no existio capacidad antibacteriana, a 75 ppm el 50% alcanzo sensibilidad limite, pero el 100% de las muestras a 125 y 175 ppm consiguieron sensibilidad limite, sin embargo, la clorhexidina al 0,12% presento mayor sensibilidad entre media 60% y sumamente sensible 40%. Conclusion: Las nanoparticulas de plata con tamano inferior a 100 nm, incluidas a 125 y 175 ppm en adhesivos de ortodoncia poseen actividad antimicrobiana sobre Streptococcus mutans, sin embargo, en el tiempo de estudio no alcanzan la sensibilidad de la clorhexidina al 0.12%. EnglishThe fixed appliances used in orthodontics make proper oral hygiene difficult, in these conditions the development of carious lesions can be a complication, one of the main etiologic agents involved is Mutans streptococci. It was determined that silver nanotechnology has an important preventive application in dental biomaterials. Objective: Antimicrobial activity on Mutans streptococci of silver nanoparticles (AgNPs) included in orthodontic adhesives at different concentrations. Materials and methods: In 20 Petri dishes with Mutans streptococci inoculated in Muller-Hinton agar supplemented with 5% blood, 6 paper discs were placed, 4 soaked up with AgNPs included in an orthodontic adhesive at concentrations of 25, 75, 125 and 175 ppm, and 2 control discs with 0.12% chlorhexidine and distilled water. Antimicrobial capacity was determined based on averages of inhibition halos at 48 hours of incubation, compared to the Duraffourd scale and 0.12% chlorhexidine. Results: At 25 ppm there was no antibacterial capacity, at 75 ppm 50% reached limit sensitivity, but 100% of the samples at 125 and 175 ppm achieved limit sensitivity, however, chlorhexidine 0.12% showed higher sensitivity between average 60% and highly sensitive 40%. Conclusion: Silver nanoparticles smaller than 100 nm, included at 125 and 175 ppm in orthodontic adhessives, have antimicrobial activity on Strptococcus mutans, however, when studying, they don’t reach the sensitivity of chlorhexidine at 0.12%.