Cyclical fatigue of four reciprocating systems in a dynamic dump of simulating roots

Abstract

The 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 Müller-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%. Conclusión: 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%.