title: Histological characterization of bleaching-induced external root resorption in dogs.
abstract: External root resorption occasionally develops after intracoronal bleaching with hydrogen peroxide. In this study, an experimental model was established to study thermocatalytic bleaching-induced root resorption in dogs. Histological examination after 6 months revealed that 18% of the teeth had root resorption lesions. The lesions could be divided into three types. In type I, root excavations were associated with a dense inflammatory cell infiltrate. Type II lesions were characterized by granulation tissue formation. In type III, the lesions were filled with reparative cementum. The three types probably represent different phases of one process. Calcium hydroxide had no effect on the occurrence or type of resorption. The instability of hydrogen peroxide and the presence of inflammatory resorption lesions 6 months postoperatively suggest hydrogen peroxide-induced toxic radicals or denaturants as potential irritants.
authors.affiliation: Department of Endodontics, Hadassah Faculty of Medicine, The Hebrew University, Jerusalem.
authors.forename: I
authors.initials: I
authors.lastname: Rotstein
authors.forename: S
authors.initials: S
authors.lastname: Friedman
authors.forename: C
authors.initials: C
authors.lastname: Mor
authors.forename: J
authors.initials: J
authors.lastname: Katznelson
authors.forename: M
authors.initials: M
authors.lastname: Sommer
authors.forename: I
authors.initials: I
authors.lastname: Bab
mesh_terms: D000818:Animals; D002126:Calcium Hydroxide / Q000627:therapeutic use*; D003739:Dental Cementum / Q000473:pathology; D003804:Dentin / Q000473:pathology; D004285:Dogs; D006861:Hydrogen Peroxide / Q000633:toxicity*; D012388:Root Canal Irrigants / Q000627:therapeutic use; D012391:Root Resorption / Q000139:chemically induced* / Q000473:pathology / Q000517:prevention & control; D014073:Tooth Bleaching / Q000009:adverse effects*
chemical_list: D012388:Root Canal Irrigants; D006861:Hydrogen Peroxide; D002126:Calcium Hydroxide