title: Tribocorrosion behavior of biofunctional titanium oxide films produced by micro-arc oxidation: Synergism and mechanisms.
abstract: Dental implants, inserted into the oral cavity, are subjected to a synergistic interaction of wear and corrosion (tribocorrosion), which may lead to implant failures. The objective of this study was to investigate the tribocorrosion behavior of Ti oxide films produced by micro-arc oxidation (MAO) under oral environment simulation. MAO was conducted under different conditions as electrolyte composition: Ca/P (0.3M/0.02M or 0.1M/0.03M) incorporated with/without Ag (0.62g/L) or Si (0.04M); and treatment duration (5 and 10min). Non-coated and sandblasted samples were used as controls. The surfaces morphology, topography and chemical composition were assessed to understand surface properties. ANOVA and Tukey׳s HSD tests were used (α=0.05). Biofunctional porous oxide layers were obtained. Higher Ca/P produced larger porous and harder coatings when compared to non-coated group (p<0.001), due to the presence of rutile crystalline structure. The total mass loss (Kwc), which includes mass loss due to wear (Kw) and that due to corrosion (Kc) were determined. The dominant wear regime was found for higher Ca/P groups (Kc/Kw≈0.05) and a mechanism of wear-corrosion for controls and lower Ca/P groups (Kc/Kw≈0.11). The group treated for 10min and enriched with Ag presented the lowest Kwc (p<0.05). Overall, MAO process was able to produce biofunctional oxide films with improved surface features, working as tribocorrosion resistant surfaces.
authors.affiliation: Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Av Limeira, 901, Piracicaba 13414-903, São Paulo, Brazil,; IBTN - Institute of Biomaterials, Tribocorrosion and Nanomedicine, USA; IBTN/Br - Institute of Biomaterials, Tribocorrosion and Nanomedicine, Brazilian Branch, Brazil.
authors.forename: Isabella da Silva Vieira
authors.initials: IDSV
authors.lastname: Marques
authors.affiliation: IBTN - Institute of Biomaterials, Tribocorrosion and Nanomedicine, USA.
authors.forename: Maria Fernanda
authors.initials: MF
authors.lastname: Alfaro
authors.affiliation: Laboratory of Technological Plasmas, Engineering College, Univ Estadual Paulista (UNESP), Av Três de Março, 511, Sorocaba 18087-180, São Paulo, Brazil.
authors.forename: Nilson Cristino da
authors.initials: NCD
authors.lastname: Cruz
authors.affiliation: Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Av Limeira, 901, Piracicaba 13414-903, São Paulo, Brazil.
authors.forename: Marcelo Ferraz
authors.initials: MF
authors.lastname: Mesquita
authors.affiliation: IBTN - Institute of Biomaterials, Tribocorrosion and Nanomedicine, USA; Departments of Chemical Engineering and Bioengineering University of Illinois at Chicago, 851 S. Morgan St., SEO 218, Chicago, IL 60607, USA.
authors.forename: Christos
authors.initials: C
authors.lastname: Takoudis
authors.affiliation: IBTN - Institute of Biomaterials, Tribocorrosion and Nanomedicine, USA; Department of Restorative Dentistry, University of Illinois at Chicago, College of Dentistry, 801 S Paulina, Chicago, IL 60612, USA.
authors.forename: Cortino
authors.initials: C
authors.lastname: Sukotjo
authors.affiliation: IBTN - Institute of Biomaterials, Tribocorrosion and Nanomedicine, USA; Department of Orthopedic Surgery, Rush University Medical Center, 1611 W Harrison, Chicago, IL 60612, USA.
authors.forename: Mathew T
authors.initials: MT
authors.lastname: Mathew
authors.affiliation: Department of Prosthodontics and Periodontology, Piracicaba Dental School, University of Campinas (UNICAMP), Av Limeira, 901, Piracicaba 13414-903, São Paulo, Brazil,; IBTN - Institute of Biomaterials, Tribocorrosion and Nanomedicine, USA; IBTN/Br - Institute of Biomaterials, Tribocorrosion and Nanomedicine, Brazilian Branch, Brazil. Electronic address: vbarao@unicamp.br.
authors.forename: Valentim Adelino Ricardo
authors.initials: VAR
authors.lastname: Barão
mesh_terms: D020099:Coated Materials, Biocompatible / Q000737:chemistry*; D003343:Corrosion; D015921:Dental Implants; D008422:Materials Testing; D010084:Oxidation-Reduction; D013499:Surface Properties; D014025:Titanium / Q000737:chemistry*
chemical_list: D020099:Coated Materials, Biocompatible; D015921:Dental Implants; C009495:titanium dioxide; D014025:Titanium
keywords: Bioactive coatings; Corrosion; Dental implants; Electrochemistry; Wear