title: Bleaching effect of sodium percarbonate on discolored pulpless teeth in vitro.
abstract: The purpose of this study was to evaluate the bleaching effect of sodium percarbonate on artificially stained pulpless teeth. Twenty extracted human mandibular premolars were stained by immersing them in human blood mixed with iron sulfide, and divided into three test groups and one control group. The following bleaching agents were used: sodium perborate mixed with 30% hydrogen peroxide (WB), sodium percarbonate mixed with distilled water (PW) or 30% hydrogen peroxide (PH). On days 5, 10, and 15, each pulp chamber was refilled with fresh bleaching paste. The L* (average lightness) of the midbuccal area of specimens was measured before and after staining, and on days 5, 10, 15, and 20 by colorimeter. The bleaching effect was evaluated by the lightness recovery rate (LRR) calculated from L*. WB showed the highest LRR among all groups, and PW and PH showed significantly higher LRR when compared with the control group. PW and PH were not significantly different. Results showed that sodium percarbonate had an obvious bleaching effect without hydrogen peroxide and indicated that it could be a safe intracoronal bleaching agent.
authors.affiliation: Department of Operative Dentistry, Hokkaido University School of Dentistry, North-13 West-7, Kita-ku, Sapporo 060-8586, Japan.
authors.forename: J
authors.initials: J
authors.lastname: Kaneko
authors.forename: S
authors.initials: S
authors.lastname: Inoue
authors.forename: S
authors.initials: S
authors.lastname: Kawakami
authors.forename: H
authors.initials: H
authors.lastname: Sano
mesh_terms: D001881:Borates / Q000627:therapeutic use; D002254:Carbonates / Q000627:therapeutic use*; D006801:Humans; D006861:Hydrogen Peroxide / Q000627:therapeutic use; D014073:Tooth Bleaching / Q000379:methods*; D014075:Tooth Discoloration / Q000188:drug therapy; D019553:Tooth, Nonvital
chemical_list: D001881:Borates; D002254:Carbonates; D006861:Hydrogen Peroxide; C027707:sodium perborate; C034738:sodium percarbonate