In vitro determination of the chromatic effect of a silver nanoparticles solution linked to the gantrez S-97 copolymer on tooth enamel.

Silver nanoparticles (NNPs), alone or in combination with the bioadhesive Gantrez S-97, have demonstrated their efficacy against Streptococcus mutans; however, it is not known if this combination changes the color of teeth. The aim of this work was to measure the color changes occurring after the use of a Gantrez-NNP combination on enamel tooth blocks. Two study groups were randomly formed: enamel blocks brushed with (a) the Gantrez-NNP combination and (b) conventional toothpaste, for 1 minute once daily for 4 weeks, then rinsed with distilled water and placed in thymol solution. Color changes in the enamel blocks were measured using a Minolta colorimeter CR300. Analysis of mixed models was performed with R 2.10.1 at a 95% confidence level, using the nonlinear mixed effects (NLME) package. The results showed that there were no color changes over time, only a high luminosity equal in both groups. Our study showed that the use of the Gantrez-NNP combination is safe with respect to dental esthetics in the control of S. mutans.