title: Effect of different EGTA concentrations on dentin microhardness.
abstract: The effect of 1%, 3% and 5% EGTA (ethylene glycol-bis-(beta-amino-ethyl ether) N,N,N',N'-tetra-acetic acid) on the microhardness of root dentin of the cervical third of human teeth was studied. Five newly extracted maxillary incisors were sectioned transversely at the cementoenamel junction, and the crowns were discarded. The roots were embedded in blocks of high-speed polymerized acrylic resin and cut transversely into 1-mm sections. The second section of the cervical third of the root of each tooth was sectioned and divided into four parts. Each part was placed on an acrylic disc that was used as a base for microhardness measurement. Fifty microliters of 1% EGTA, 3% EGTA, or 5% EGTA were applied to the dentin surface. Deionized and distilled water was used as control. Dentin microhardness was then measured with a load of 50 g for 15 s. Statistical analysis showed that the three concentrations of the chelating solution EGTA significantly reduced dentin microhardness when compared with water (ANOVA, p < 0.01), and that there was a statistically significant difference among the three solutions (Tukey test, p < 0.05).
authors.affiliation: Faculty of Dentistry, University of Ribeirão Preto, Ribeirão Preto, SP, Brazil. cruz@online.unaerp.br
authors.forename: Antonio Miranda da
authors.initials: AM
authors.lastname: Cruz-Filho
authors.forename: Eduardo Augusto de
authors.initials: EA
authors.lastname: Paula
authors.forename: Jesus Djalma
authors.initials: JD
authors.lastname: Pécora
authors.forename: Manoel Damião de
authors.initials: MD
authors.lastname: Sousa-Neto
mesh_terms: D000704:Analysis of Variance; D002614:Chelating Agents / Q000008:administration & dosage*; D003799:Dental Stress Analysis; D003804:Dentin / Q000187:drug effects*; D004533:Egtazic Acid / Q000008:administration & dosage*; D006244:Hardness / Q000187:drug effects*; D006801:Humans; D007180:Incisor; D008422:Materials Testing; D012388:Root Canal Irrigants / Q000008:administration & dosage*; D016369:Smear Layer; D018709:Statistics, Nonparametric; D019237:Tooth Cervix / Q000187:drug effects
chemical_list: D002614:Chelating Agents; D012388:Root Canal Irrigants; D004533:Egtazic Acid