Effect of Autoclaving Time on Corrosion Resistance of Sandblasted Ti G4 in Artificial Saliva

Abstract

Titanium Grade 4 (Ti G4) is the most commonly used material for dental implants due to its excellent mechanical properties, chemical stability and biocompatibility. A thin, self-passive oxide layer with protective properties to corrosion is formed on its surface. However, the spontaneous TiO2 layer is chemically unstable. In this work, the impact of autoclaving time on corrosion resistance of Ti G4 in artificial saliva solution with pH = 7.4 at 37 °C was studied. Ti G4 was sandblasted with white Al2O3 particles and autoclaved for 30–120 min. SEM, EDS, 2D roughness profiles, confocal laser scanning microscopy, and a Kelvin scanning probe were used for the surface characterization of the Ti G4 under study. In vitro corrosion resistance tests were conducted using open circuit potential, polarization curves, and electrochemical impedance spectroscopy measurements. It was found that Sa parameter, electron work function, and thickness of the oxide layers, determined based on impedance measurements, increased after autoclaving. The capacitive behavior and high corrosion resistance of tested materials were revealed. The improvement in the corrosion resistance after autoclaving was due to the presence of oxide layers with high chemical stability. The optimal Ti G4 surface for dentistry can be obtained by sandblasting with Al2O3 with an average grain size of 53 µm, followed by autoclaving for 90 min.

Corrosion Resistance of the CpTi G2 Cellular Lattice with TPMS Architecture for Gas Diffusion Electrodes

“…The average j cor values for all CpTi G2 cellular lattice with TPMS architecture and bulk electrode are on the order of 10 −7 A cm −2 . These j cor values are typical for titanium in low concentrated aqueous solutions [ 52 , 53 ]. The highest average j cor of 8.96(5) × 10 −7 A cm −2 is observed for the CpTi G2 bulk electrode ( Table 3 ).…”

“…One time constant is visible in the electrical circuit for all cellular lattices. Such impedance behavior is typical for metallic electrodes covered with oxide layer [ 52 , 56 ]. For the bulk electrode, two time constants are present in the electrical circuit.…”

“…After reaching the maximum in the initial stage of the study, the EOC values slightly decrease with immersion time for this electrode, whereupon a nearly constant value of the potential is observed due to the stability of the passive layer. The reason for that probably can be the slow dissolution of the spontaneous oxide layer [52]. The course of the E OC = f (t) curves is mild.…”

“…The EIS results with respect to the barrier properties of the passive oxide layers on the surface of CpTi G2 cellular lattice were approximated using the equivalent electrical circuit model shown in Figure 10c. This is the so-called one-CPE model with four adjustable parameters: Rs, Tdl, dl, and Rox, and displays one semicircle on the complex-plane plot [52,56]. In this model, Rs is the solution resistance, Rox is the charge transfer resistance through the TiO2|electrolyte interface, and the CPEdl is the constant phase element (CPE) which is a nonlinear element introduced instead of a capacitor corresponding to the elec- The EIS results with respect to the barrier properties of the passive oxide layers on the surface of CpTi G2 cellular lattice were approximated using the equivalent electrical circuit model shown in Figure 10c.…”

“…In this model, Rs is the solution resistance, Rox is the charge transfer resistance through the TiO2|electrolyte interface, and the CPEdl is the constant phase element (CPE) which is a nonlinear element introduced instead of a capacitor corresponding to the elec- The EIS results with respect to the barrier properties of the passive oxide layers on the surface of CpTi G2 cellular lattice were approximated using the equivalent electrical circuit model shown in Figure 10c. This is the so-called one-CPE model with four adjustable parameters: R s , T dl , φ dl , and R ox , and displays one semicircle on the complex-plane plot [52,56]. In this model, R s is the solution resistance, R ox is the charge transfer resistance through the TiO 2 |electrolyte interface, and the CPE dl is the constant phase element (CPE) which is a nonlinear element introduced instead of a capacitor corresponding to the electrical double layer capacitance.…”