Tooth Bleaching Compositions
The present invention relates to improved dental compositions and methods for bleaching teeth. More specifically, this invention is directed towards hydrogen peroxide-containing compounds that are maintained at a substantially constant pH range of 6.0-10.0 during the tooth-bleaching procedure in the presence of a calcium chelating agent.
1 - 14 . (canceled)
15 . A tooth bleaching composition comprising:
hydrogen peroxide,
and a matrix for carrying the hydrogen peroxide, the matrix having
a water content of at least 75% by weight, based on the weight of the composition,
a concentration of high molecular weight crosslinked polyacrylic acid of between approximately 2.0% and approximately 5.0% by weight, based on the weight of the composition,
an alkaline pH adjusting agent, and
a concentration of a stabilizing agent selected from the group consisting of sodium stannate trihydrate, 1-Hydroxyethylidene-1,1-diphosphonic acid, and combinations thereof, of between approximately 0.02% and approximately 0.5% by weight, based on the weight of the composition,
wherein the pH of the composition during the bleaching process is substantially constant within a range of between approximately 6.0 and approximately 10.0.
16 . A composition according to claim 15 , wherein the concentration of hydrogen peroxide in the composition is less than 15% by weight of the composition.
17 . A composition according to claim 15 , wherein the matrix is sufficiently pure in order to avoid peroxide destabilization by metal ion contaminants, so as to permit packaging as a one-component system.
18 . A composition according to claim 15 , wherein the pH of the composition during the bleaching process is substantially constant within a range preferred for use within an oral cavity of between approximately 6.0 and approximately 8.0.
19 . A composition according to claim 15 , wherein the matrix also has a concentration of a calcium chelating agent of between approximately 0.02% and approximately 0.4% by weight, based on the weight of the composition.
20 . A composition according to claim 15 , wherein the stabilizing agent may also act as a calcium chelating agent.