title: Dentin is dissolved by high concentrations of L-ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-1-benzopyran-6-yl-hydrogen phosphate] potassium salt with or without hydrogen peroxide.
abstract: L-Ascorbic acid 2-[3,4-dihydro-2,5,7,8-tetramethyl-2-(4,8,12-trimethyltridecyl)-2H-1-benzopyran-6-yl-hydrogen phosphate] potassium salt (EPC-K(1)) is a conjugate of vitamin C and vitamin E that is water-soluble and stable at room temperature. EPC-K(1) has been developed as a hydroxyl radical (.OH) scavenger and antioxidant. In a previous tooth whitening experiment, it was accidentally found that tooth (dentin) blocks were dissolved by EPC-K(1) with H(2)O(2). In the current study, high concentrations of EPC-K(1) (2.5, 25 mM) with 3% H(2)O(2) dissolved and caused the collapse of dentin blocks. Similar concentrations of EPC-K(1) without 3% H(2)O(2), however, dissolved the dentin blocks without collapse over a 3-week period. In these cases, a.OH-like signal was detected using an ESR spin-trapping method. The volume of calcium in solution (including the dentin block) increased on the addition of EPC-K(1) in a concentration-dependent manner. In addition, the calcium : phosphorus ratio changed from 2 : 1 in sound dentin to 1 : 2 in the collapsed dentin block. High concentrations of EPC-K(1) are therefore considered to have calcium chelating and dentin dissolving activity. The dentin dissolving activity was enhanced when EPC-K(1) was used with H(2)O(2). EPC-K(1) had no protective effect when used in tooth whitening with H(2)O(2).
authors.affiliation: Research Institute of Oral Science, Department of Endodontics, Nihon University School of Dentistry at Matsudo, Chiba, Japan.
authors.forename: Masahiro
authors.initials: M
authors.lastname: Kozuka
authors.forename: Yasuhisa
authors.initials: Y
authors.lastname: Tsujimoto
mesh_terms: D001205:Ascorbic Acid / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology; D003804:Dentin / Q000737:chemistry* / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D006861:Hydrogen Peroxide / Q000737:chemistry* / Q000378:metabolism; D012995:Solubility / Q000187:drug effects; D014810:Vitamin E / Q000031:analogs & derivatives* / Q000737:chemistry* / Q000378:metabolism / Q000494:pharmacology
chemical_list: D014810:Vitamin E; C066638:potassium ascorbyl tocopheryl phosphate; D006861:Hydrogen Peroxide; D001205:Ascorbic Acid