title: Effect of time interval between bleaching and bonding on tag formation.
abstract: The objective of this study was to assess penetration of adhesive material in enamel bleached with 35% hydrogen peroxide using optical polarized light microscopy. Extracted human teeth were randomly assigned to 5 groups, each representing a specific time interval between bleaching and the application of an adhesive material. They were designated as: (TC) the control group-restorations in unbleached teeth; (T0) comprising restorations carried out immediately after bleaching; (T7) comprising restorations 7 days after bleaching; (T14) comprising restorations 14 days after bleaching; and (T21) comprising restorations 21 days after bleaching. Length of resin tags was measured with an Axiophot photomicroscope at a x 400 magnification, and the results subjected to an ANOVA for a comparison between groups, with a p value of < 0.05. Differences between the groups were verified using a Tukey test at a confidence level of 5%. The specimens in the control group (TC) and experimental groups T7, T14 and T21 showed better penetration of adhesive material into enamel in comparison with experimental group T0. This suggests that a gap of at least 7 days should be left between bleaching enamel with 35% hydrogen peroxide and placing adhesive bonding agents and undertaking resin composite restoration work.
authors.affiliation: Department of Restorative Dentistry, Araçatuba School of Dentistry, Paulista State University, UNESP, Rua José Bonifácio 1193, CEP: 16015 050, Araçatuba, São Paulo, Brazil. sundfeld@terra.com.br
authors.forename: Renato Herman
authors.initials: RH
authors.lastname: Sundfeld
authors.forename: André Luiz Fraga
authors.initials: AL
authors.lastname: Briso
authors.forename: Patricia Marra
authors.initials: PM
authors.lastname: De Sá
authors.forename: Maria Lúcia Marçal Mazz
authors.initials: ML
authors.lastname: Sundfeld
authors.forename: Ana Karina Barbieri
authors.initials: AK
authors.lastname: Bedran-Russo
mesh_terms: D000180:Acrylic Resins / Q000627:therapeutic use; D000269:Adhesives / Q000737:chemistry; D000293:Adolescent; D000704:Analysis of Variance; D002648:Child; D003188:Composite Resins / Q000627:therapeutic use; D001840:Dental Bonding; D004338:Drug Combinations; D006801:Humans; D010545:Peroxides / Q000009:adverse effects*; D011140:Polyurethanes / Q000627:therapeutic use; D011145:Polyvinyls / Q000009:adverse effects*; D013997:Time Factors; D014073:Tooth Bleaching / Q000009:adverse effects*; D014508:Urea / Q000009:adverse effects / Q000031:analogs & derivatives*
chemical_list: D000180:Acrylic Resins; D000269:Adhesives; C029012:Composite Dental Resin; D003188:Composite Resins; D004338:Drug Combinations; D010545:Peroxides; D011140:Polyurethanes; D011145:Polyvinyls; C093177:tooth-bleaching agent, Opalescence; D014508:Urea