DEVELOPMENT, CHARACTERIZATION AND STABILITY STUDY OF NANOMETRIC SYSTEMS CONTAINING HYDROGEN PEROXIDE FOR DENTAL BLEACHING

The appreciation of appearance is increasingly widespread in the media and involves a smile-related beauty standard. Any change in teeth compromises the appearance and may reflect on the psychological and social behaviour of the human being. Consequently, there has been technological advance in aesthetic and technical restorative materials, such as dental bleaching, as well as the development of more effective drug delivery techniques, such as micro-emulsions and liquid crystals. In this work, dispersed systems containing hydrogen peroxide were developed, characterized and evaluated for dental bleaching agents, with permeation potential in the dentinal tubules in order to optimize the bleaching process. Two pseudo-ternary diagrams were developed. Two formulations of the second diagram were selected and characterized (optical microscopy, pH, particle size, polydispersity index, zeta potential), and then, preliminary and accelerated stability study. In these formulations, the hydrogen peroxide was incorporated in concentrations 6 and 14%. The photomicrographs of the formulations revealed dark field, characteristic of the cubic phases. The product containing 6% hydrogen peroxide obtained pH values of 6.06 ± 0.06; Zeta potential of -6.36 ± 0.6 mV; Droplet size of 9.63 ± 0.01 mV and Polydispersity index of 0.15 ± 0.002. The product containing 14% hydrogen peroxide obtained pH values of 5.93 ± 0.06; Zeta potential of -4.99 ± 0.3 mV; Droplet size of 9.62 ± 0.006 nm and polydispersity index of 0.16 ± 0.007. The rheological profile of the analyzed samples presented with thixotropic behaviour. The results suggest that the nanodisperse systems obtained are liquid crystals of cubic phase.