Corrosion resistance of coupled sandblasted, large-grit, acid-etched (SLA) and anodized Ti implant surfaces in synthetic saliva

Abstract

Purpose: The purpose of this study was to investigate the corrosion resistance of galvanically coupled SLA and anodized implant surfaces with a Co-Cr alloy. Materials and Methods: Three groups were included in this study. The first (SLA) was composed of SLA implants (Institut Straumann, Basel, Switzerland), the second (ANO) of NobelReplace® (Nobel Biocare, Göteborg, Sweden), and the third (MIX) of both implant systems combined. All groups were assembled with a single Co-Cr superstructure. Electrochemical testing included open-circuit potential, electrochemical impedance spectroscopy, cyclic potentiodynamic polarization, and chronoamperometric current-time measurements. The quantitative results (EOCP, ECORR, ICORR, EPROT, RP, and ICA) were statistically analyzed by one-way ANOVA and Tukey's post-hoc multiple comparison test (α = 0.05). Results: All the aforementioned parameters showed statistically significant differences apart from ECORR and EPROT. The evaluation of qualitative and quantitative results showed that although SLA had higher corrosion resistance compared with ANO, it had less resistance to pitting corrosion. This means that SLA showed increased resistance to uniform corrosion but less resistance if pitting corrosion was initiated. In all cases, MIX showed intermediate behavior. Conclusion: The corrosion resistance of implant-retained superstructures is dependent on the electrochemical properties of the implants involved, and thus different degrees of intraoral corrosion resistance among different implant systems are anticipated.