Long-term assessment of the implant titanium material—artificial saliva interface

Abstract

This paper studies the long-term (20,000 exposure hours) behavior of titanium and Ti-5Al-4V alloy-Carter-Brugirard saliva interface and the short-term (500 exposure hours) resistance of titanium and Ti-5Al-4V alloy-Tani&Zucchi saliva interface. Potentiodynamic polarization method was applied for the determination of the main electrochemical parameters. Linear polarization measurements for to obtain the corrosion rates were used. Monitoring of the open circuit potentials (E(oc)) for long-term have permitted to calculate the potential gradients due to the pH, DeltaE(oc)(pH) and to the saliva composition DeltaE(oc)(c) changes which can appear "in vivo" conditions and can generate local corrosion. Atomic force microscopy (AFM) has analyzed the surface roughness. Ion release was studied by atomic absorption spectroscopy (AAS). In Carter-Brugirard saliva both titanium and Ti-5Al-4V alloy present very stable passive films, long-term stability, "very good" resistance, low values of the open circuit potential gradients, which cannot generate local corrosion. In Tani&Zucchi artificial saliva, pitting corrosion and noble pitting protection potentials (which cannot be reached in oral cavity) were registered; titanium ion release is very low; surface roughness increase in time and in the presence of the fluoride ions, denoting some increase in the anodic activity.

Corrosion resistance improvement of titanium base alloys

“…29 The fluoride ion has a slow negative influence on the electrochemical parameters due its higher corrosivity. 24,30,31 In comparison with Ti-6Al-4V alloy, from Table 4 it resulted more favorable values of all electrochemical parameters for Ti-6Al-4V-1Zr alloy, revealing the beneficial effect of Zr.…”

“…In the presence of fluoride ions, open circuit potential changed to more electronegative values due to the negative effect of F -ion; 24,30,35 the same tendency to stabilize and to ennoble was registered, showing a good, resistant passive layer.…”

“…24,25 In Figure 1, 26 an electric equivalent circuit with two time constants (Figure 2) was modeled: one constant is for the inner, thin, barrier, compact, passive film illustrated by the compact layer resistance, R 1 and capacitance CPE 1 (a constant phase element to describe the deviation from an ideal capacitor due to the certain heterogeneity of the surface); 25 the second time constant is for the outer, porous layer and is represented by the porous layer resistance, R 2 and capacitance CPE 2 .…”

Avaliação de massa e rugosidade superficial de pastilhas de Ti-6Al-4V com aplicação de nanopartículas de prata submetidos ao teste de escovação

“…A ação mecânica dos abrasivos dos dentifrícios juntamente com a ação das cerdas das escovas foi responsável pela variação da rugosidade dos espécimes, também observada por outros autores (HOSSAIN et al, 2006(HOSSAIN et al, ,2007FAIS et al,2012;SIIRILÄ E KÖNÖNEM, 1991;SALLES et al, 2009 MAYOUF et al, 2004;SARTORI et al, 2009;TONIOLLO et al, 2009;MABILLEAU et al, 2006;POPA et al, 2008;LEE, 2005) e/ou o biofilme específico (ZHANG et al, 2013;SOUZA et al, 2010).…”

“…A redução da proteção contra corrosão e consequente variação da rugosidade média do titânio e suas ligas foi encontrado nos estudos de Siirila e Kononen (1991), onde a concentração era de 12500 ppm; Mabilleau et al (2006), 5000 e 25000 ppm; Popa et al (2008) Na caracterização dos componentes químicos dos corpos de prova, EDS, não detectou-se a presença de sílica, tampouco compostos fluoretados ou sódicos após os testes de escovação e imersão, indicando que a reação do NaF do dentifrício e a superfície da liga de titânio não foi significativamente alterada, corroborando com os estudos expostos na literatura (NAKAGAWA et al, 1999(NAKAGAWA et al, , 2001(NAKAGAWA et al, , 2002AL-MAYOUF et al, 2004;MABILLEAU et al, 2006;MATONO et al, 2006;STAJER et al, 2008;FAIS et al, 2012;JOSKA;FOJT, 2010;MUGURUMA et al, 2011), onde a concentração de até 1500 ppm de F-não é suficiente para a degradação da superfície do titânio e suas ligas.…”