Effect Of Electrolytic Cleaning on Mechanical Properties for Titanium Dental Implants with Surface Contamination

Purpose: Recently, galvanic cleaning techniques, such as Galvosurge®, which utilize hydrogen formation, have demonstrated significant efficacy in removing biofilm during the  decontamination of implant surfaces in the reconstructive therapy of peri-implantitis, This decontamination method avoids the mechanization of the implant and therefore avoids the loss of mechanical properties, loss of good corrosion behavior and avoids the release of particles of different sizes with possible toxic effects, However, the formation of hydrogen on the surface could cause diffusion into the titanium and lead to hydrogen embrittlement of the dental implant, In this study we intend to study the effect of this treatment on the mechanical properties of dental implants, Materials and methods: Ninety dental implants were studied, of which 30 were control, 30 were treated with Galvosurge® and 30 were treated with concentrated hypochlorous acid, The amount of hydrogen in the titanium interior was determined for each of the samples by spectroscopy to elemental analysis of hydrogen TCH600 LECO. Electrochemical corrosion tests were performed on 30 dental implants to determine the corrosion potentials and corrosion intensity for the different treatments. One important factor for the fatigue behavior are the residual stresses which were studied by by Bragg–Bentano X-ray diffraction. Residual stresses were studied by by Bragg–Bentano X-ray diffraction. Fatigue tests were performed using a servohydraulic machine determining the S-N curves by performing triaxial tests (tensioncompression and 5 ̊ torsion) at different loads to simulate human mastication. A study of the fractures of the dental implants was carried out by scanning electron microscopy and the samples were observed by transmission electron microscopy to observe the possible appearance of hydrides in the titanium microstructure, Results: The results showed that the electrolytic technique reduces the presence of hydrogen in the dental implant and the acid treatment increases it causing the presence of hydrides at the grain boundaries of the titanium, It has been shown that galvanic treatments do not affect the corrosion resistance of dental implants. However, attacks with hypochlorous acid increase the corrosion rate due to the acid attack on the titanium surface that favors pitting points. Fatigue tests show that dental implants treated with Galvosurge® have a longer fatigue life than the control due to the lower hydrogen content, It was shown that the increase of hydrogen in the acid-treated implants reduces the fatigue life of the dental implant, Conclusions: This study allows us to conclude that the formation of hydrogen by electrolysis does not cause a diffusion of this element to the titanium nor does it affect corrosion resistance but on the contrary reduces the level of hydrogen which favors its mechanical properties in the long term.