title: Influence of root dentin treatment on the push-out bond strength of fibre-reinforced posts
abstract: This study evaluates the influence of root dentin treatment with NaOCl alone and combined with EDTA, with and without ultrasound activation, on the push-out bond strength (BS) of fiber-reinforced posts in weakened roots, cemented with RelyX or Panavia. The root canals of 42 maxillary canines were instrumented with Reciproc and 2.5% NaOCl. In the coronal 12mm of all canals, experimental weakening of the roots was produced by reducing dentin thickness with 2.44mm diameter diamond burs. The roots were assigned to 3 groups (n = 14) according to root dentin treatment: 2.5% NaOCl; 2.5% NaOCl + 17% EDTA; and 2.5% NaOCl + 17% EDTA, with solutions agitated using passive ultrasonic irrigation. After cementation of the fiber-reinforced posts the roots were divided in thirds. The first slice of each third was used for the push-out BS test, the second slice for confocal laser scanning microscopy and dentin microhardness (Knoop) analysis. Data were analysed by a two-way ANOVA and Tukey test (a = 0.05). NaOCl + EDTA provided highest BS values than NaOCl (p < 0.0001). Specimens cemented with Panavia presented significantly higher BS than those with RelyX in the three root thirds (p < 0.0001). The highest BS values occurred in the cervical third (p < 0.001). Ultrasound-activated NaOCl + EDTA promoted the greatest reduction in dentin microhardness, followed by NaOCl/EDTA and NaOCl. Ultrasonic activation of NaOCl and EDTA reduced root dentin microhardness, but did not improve the push-out BS of resin-based cements. Panavia presented higher BS than RelyX. RelyX was not influenced by the root dentin treatment protocols.
authors.affiliation: Universidade Estadual de Montes Claros - Unimontes, Interinstitutional PhD program, Montes Claros, MG, Brazil.
authors.forename: Altair Soares
authors.initials: AS
authors.lastname: Moura
authors.affiliation: Universidade de São Paulo - USP, Ribeirão Preto Dental School, Department of Restorative Dentistry, Ribeirão Preto, SP, Brazil.
authors.forename: Rodrigo Dantas
authors.initials: RD
authors.lastname: Pereira
authors.affiliation: Universidade de Ribeirão Preto - Unaerp, Department of Dentistry, Ribeirão Preto, SP, Brazil.
authors.forename: Fuad Jacob Abi
authors.initials: FJ
authors.lastname: Rached
authors.affiliation: Universidade de São Paulo - USP, Ribeirão Preto Dental School, Department of Restorative Dentistry, Ribeirão Preto, SP, Brazil.
authors.forename: Bruno Monguilhott
authors.initials: BM
authors.lastname: Crozeta
authors.affiliation: Universidade de São Paulo - USP, Ribeirão Preto Dental School, Department of Restorative Dentistry, Ribeirão Preto, SP, Brazil.
authors.forename: Jardel Francisco
authors.initials: JF
authors.lastname: Mazzi-Chaves
authors.affiliation: Universidade de São Paulo - USP, Ribeirão Preto Dental School, Department of Restorative Dentistry, Ribeirão Preto, SP, Brazil.
authors.forename: Luis Eduardo
authors.initials: LE
authors.lastname: Souza-Flamini
authors.affiliation: Universidade de São Paulo - USP, Ribeirão Preto Dental School, Department of Restorative Dentistry, Ribeirão Preto, SP, Brazil.
authors.forename: Antonio Miranda
authors.initials: AM
authors.lastname: Cruz
mesh_terms: D000134:Acid Etching, Dental / Q000379:methods; D000704:Analysis of Variance; D001840:Dental Bonding / Q000379:methods*; D019232:Dental Restoration Failure; D003804:Dentin / Q000187:drug effects* / Q000528:radiation effects; D004492:Edetic Acid / Q000737:chemistry*; D006245:Hardness Tests; D006801:Humans; D008422:Materials Testing; D018613:Microscopy, Confocal; D011176:Post and Core Technique; D011897:Random Allocation; D012016:Reference Values; D015203:Reproducibility of Results; D019279:Resin Cements / Q000737:chemistry*; D012388:Root Canal Irrigants / Q000737:chemistry; D018915:Root Canal Preparation / Q000379:methods; D012973:Sodium Hypochlorite / Q000737:chemistry*; D018709:Statistics, Nonparametric; D013499:Surface Properties / Q000187:drug effects; D014092:Tooth Root / Q000187:drug effects* / Q000528:radiation effects; D014464:Ultrasonic Therapy
chemical_list: C438843:Panavia-Fluoro; C587242:RelyX U200; D019279:Resin Cements; D012388:Root Canal Irrigants; D004492:Edetic Acid; D012973:Sodium Hypochlorite