In vitro tooth whitening efficacy of carbamide peroxide polyelectrolyte gel and colorimetric evaluation, stability, and hydrogen peroxide release

We fabricate a new gel containing carbopol, anionic polyacrylamide APAM polyelectrolyte, and carbamide peroxide CP 16% and evaluate its efficacy in the whitening of discolored teeth. The prepared gel was characterized by FT-IR and XRD. Fifteen extracted human teeth were used and the initial color has been evaluated by using the Vita coloration guide and standardized pictures. The teeth were stained in coffee solution for two weeks; the color assessment of discolored teeth was performed. The teeth were divided into four groups, they were immersed in the coffee solution for a different time and applied different whitening methods. The results showed that similar whitening results for the experimental groups at the end of the 14th day. These groups gave a higher whitening effect than the control group (G0). The whitening gel was effective in the bleaching of teeth stained by coffee, particularly at the end of the 14th day. Hydrogen peroxide content was determined in vitro by titration method; release kinetics was assessed by a modified spectrophotometric technique.Graphical Abstract