Hibridização do esmalte dentário com resina fluida usando o fluxo eletrocinético

The transport of materials trough dental enamel has been regarded as dependent on diffusion which doesn´t infiltrate the nanopores of normal dental enamel normal, being these materials considered as above the threshold for enamel nanopores (MATEN). In this in vitro study, applied the electrokinetic flow (EKF) to infiltrated the MATEN into the dental enamel pores mature of unerupted permanent human teeth. It were tested an aqueous solutions with refractive index of 1.56 (Thoulet’s solution) by 5h and a infiltrant resin ICON® by three different times (1; 1,5 and 2 h), both with pH higher than the critical pH of enamel, applying 5V in both cases. Dental enamel ground sections were mounted on customized microfluidic chips made of poly-methyl-siloxane and submitted to EKF. A pre-infiltration with 1 mM KCl solution by 2 h and 1V. Three samples were infiltrated by 1.56 Thoulet´s solution and eight samples were infiltrated using infiltrant resin. Histological sites (n = 30) in Thoulet´s group were analyzed for water birefringence before and after infiltrated. The sample of resin group were subsequently exposed to in vitro demineralization by 192h. The depth of hybrid layer was analyzed by fluorescence and polarizing microscopy. The analysis of mineral volume by radiomicrography was performed in infiltrated histological sites (n = 30) and not infiltrated histological sites (n = 30), before the infiltrated and after demineralization, always hydrated. The negative birefringence of histological points (n = 30) in water, before infiltration of Thoulet’s solution (mean of -22.47 x 10-4) was significantly lower than after the infiltrated of Thoulet’s solution 1.56 (mean of – 51.7 x 10-4) (p < 0.00001; ANOVA; effect size = 6.69). Depth of enamel hybrid layer ranged for 640 m to 1430 m (mean of 760 m). The hydrated minerals volumes of infiltrated parts before demineralization were similar to after demineralization (p = 0.123; T test) while the not infiltrated parts presented similar hydrated mineral volumes after ...