title: Nanomechanical properties, SEM, and EDS microanalysis of dentin treated with 2.5% titanium tetrafluoride, before and after an erosive challenge.
abstract: The aim was to assess the nanohardness (H) and the reduced modulus of elasticity (Er ) of 2.5% titanium tetrafluoride (TiF4 ) modified dentin, before and after an erosive challenge with 0.3% citric acid (CA). Exposed dentin surfaces were divided into two groups (n = 5): (1) Control-no dentin pretreatment with TiF4 prior to etching with CA, and (2) Experimental-dentin pretreatment with TiF4  + CA. The H and the Er of intertubular dentin were measured using a triboindenter at different time points: baseline for both groups, after using 2.5% TiF4 for the experimental group, and after using CA for both the experimental and the control groups. Scanning electron microscope and energy dispersive X-ray spectroscopy (EDS) analysis of the dentin surfaces were undertaken at the same time points for both groups. Two-way ANOVA for randomized block design was applied. There was significant interaction between the application of the TiF4 solution and different time points (p = 0.001 for H and p < 0.001 for Er ), identified by Tukey's test. Erosive challenge provided a significant decrease in H and Er mean values. The TiF4 solution caused a significant increase in H and Er values, but no significant differences were found between post-TiF4 and post-CA application. TiF4 application produced a precipitate surface layer on intertubular and intratubular dentin. EDS analysis indicated the presence of titanium. The H and Er of the dentin surface were greatly increased after application of 2.5% TiF4 . TiF4 may modify the micromorphology of the dentin surface and produces an erosive resistance surface.
authors.affiliation: Department of Restorative Dentistry, São Leopoldo Mandic School of Dentistry and Research Institute, Campinas, São Paulo, Brazil.
authors.forename: Roberta Tarkany
authors.initials: RT
authors.lastname: Basting
authors.forename: Ariene Arcas
authors.initials: AA
authors.lastname: Leme
authors.forename: Enrico Coser
authors.initials: EC
authors.lastname: Bridi
authors.forename: Flávia Lucisano Botelho do
authors.initials: FL
authors.lastname: Amaral
authors.forename: Fabiana Mantovani Gomes
authors.initials: FM
authors.lastname: França
authors.forename: Cecília Pedroso
authors.initials: CP
authors.lastname: Turssi
authors.forename: Ana Karina
authors.initials: AK
authors.lastname: Bedran-Russo
mesh_terms: D015502:Absorptiometry, Photon; D003804:Dentin / Q000737:chemistry* / Q000648:ultrastructure*; D005459:Fluorides / Q000737:chemistry*; D006244:Hardness; D006801:Humans; D008855:Microscopy, Electron, Scanning; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D014025:Titanium; D005459:Fluorides; C032240:titanium tetrafluoride
keywords: dentin; erosion; nanohardness; titanium tetrafluoride