An experimental investigation on the effect of chlorxexidine concentration on the corrosion of Ti-6Al-4V alloy

Abstract

Introduction: Corrosion of dental implants is a very important factor in the failure of implant treatments, and on the other hand, it depends on the type of material used in the construction of the implant and the chemical composition of the oral environment. Chlorhexidine mouthwashes and gels are often used after implant surgeries for antibacterial activities in the vicinity of the implant, which also creates a special chemical composition in the implant environment. The aim of this study was to investigate the corrosion behavior of Ti-6Al-4V alloy (as one of the most important alloys in the manufacture of dental implants) at different concentrations of chlorhexidine chloride. Methods and Materials: This experimental study was performed on 24 samples of Ti-6Al-4V including 6 samples in each of the four groups of ringer solution (as artificial saliva medium) and chlorhexidine solutions of 0.12%, 0.2% and 2%. Samples were immersed in 4 corrosion solutions in 2 batches for 2 and 24 hours. Corrosion behavior of the samples was investigated using Open Circuit Potential (OCP), TOEFL polarization and Electrochemical Impedance Spectroscopy (EIS). SEM microscopy was used to examine the morphology and cross section of the samples after corrosion. Results: The results showed that although all samples were relatively stable for a short period of time, indicating high thermodynamic stability and reduced driving force of the corrosion process, however, the samples were thermodynamically resistant to corrosion in 0.12% chlorhexidine solutions and in the next categories were 0.2% and 2% solutions, respectively. The best stability of the samples was obtained in 2 hours of immersion in 0.12% chlorhexidine solution and then in 2% and 0.2% solutions, respectively. Also, the samples in 0.12% chlorhexidine solution in both 2 and 24 hours of immersion showed better resistance to the penetration of corrosive agents, and 2% and 0.2% solutions were in the next ranks, respectively. Conclusion: The use of chlorhexidine solution with a concentration of 0.12% after implant surgery can have less effect on the degree of corrosion of dental implants.