title: Permeability of different groups of maxillary teeth after 38% hydrogen peroxide internal bleaching.
abstract: This study evaluated the influence of internal tooth bleaching with 38% hydrogen peroxide (H2O2) on the permeability of the coronal dentin in maxillary anterior teeth and premolars. Seventy teeth (14 per group) were used: central incisors (CI), lateral incisor (LI), canines (C), first premolars (1PM) and second premolars (2PM). Pulp chamber access and transversal sectioning at 2 mm from the cementoenamel junction were performed and the specimens were divided into 2 groups (n= 7): a) no treatment and b) bleaching with 38% H2O2. The bleaching agent was applied to the buccal surface and to the pulp chamber for 10 min. This procedure was repeated 3 times. The specimens were processed histochemically with copper sulfate and rubeanic acid, sectioned longitudinally, and digitalized in a scanner. The area of stained dentin was measured using Image Tool software. Data were analyzed statistically by ANOVA and Tukey's HSD test (alpha=0.05). There was statistically significant difference (p<0.001) among the untreated groups, CI (0.23 +/- 0.26) having the lowest permeability and LI (10.14 +/- 1.89) the highest permeability. Among the bleached groups, dentin permeability was increased in all groups of teeth except for 2PM. It may be concluded that bleaching with 38% H2O2 affected dentin permeability near the pulp chamber in maxillary anterior teeth and in first and second premolars.
authors.affiliation: Department of Endodontics, Dental School, University of Ribeirão Preto, Ribeirão Preto, SP, Brazil.
authors.forename: Lívia Maria
authors.initials: LM
authors.lastname: Rodrigues
authors.forename: Luis Pascoal
authors.initials: LP
authors.lastname: Vansan
authors.forename: Jesus Djalma
authors.initials: JD
authors.lastname: Pécora
authors.forename: Melissa Andréia
authors.initials: MA
authors.lastname: Marchesan
mesh_terms: D004396:Coloring Agents / Q000494:pharmacology; D003300:Copper / Q000494:pharmacology; D003745:Dental Enamel Permeability / Q000187:drug effects; D003786:Dental Pulp Cavity / Q000187:drug effects*; D003806:Dentin Permeability / Q000187:drug effects*; D006801:Humans; D006861:Hydrogen Peroxide / Q000494:pharmacology*; D008437:Maxilla; D016877:Oxidants / Q000494:pharmacology; D012388:Root Canal Irrigants / Q000494:pharmacology*; D014073:Tooth Bleaching / Q000379:methods*; D019553:Tooth, Nonvital
chemical_list: D004396:Coloring Agents; D016877:Oxidants; D012388:Root Canal Irrigants; D003300:Copper; D006861:Hydrogen Peroxide