Hypochlorous acid as a promising decontamination agent for titanium implants: An in vitro study on surface integrity and biofilm control

BACKGROUND Chemical decontamination is essential for effective peri-implantitis treatment. Hypochlorous acid (HOCl) is tissue-safe and exhibits broad microbicidal activity. This study compared its effects on titanium surface structure, biofilm removal, and biofilm formation with those of other decontamination agents. METHODS In this in vitro study, HOCl, chlorhexidine gluconate (CHX), and citric acid (CA) were applied to sterile titanium disks using by rubbing and immersion methods for 8 minutes. Surface roughness and morphology changes were analyzed via atomic force microscopy and scanning electron microscopy. New biofilm formation on pretreated titanium disks with decontamination solutions and biofilm removal efficiency were measured via optical density via a spectrophotometer. One-way ANOVA was performed on the normalized biofilm values, and Tukey’s test was employed as post-hoc test to normally distributed variables, while log _e transformation was applied to the surface roughness before analysis to stabilize the variance. A t-test was used to compare methods in test solutions. RESULTS In both the immersion and rubbing methods, the HOCl group had the lowest roughness values after the control group, with a statistically significant difference compared with to the CA group ( p < 0.05). Within each group, roughness did not vary significantly between methods. HOCl was the most effective at reducing biofilm formation, with a statistically significant difference from CA during immersion ( p < 0.01) and from CHX during rubbing ( p < 0.01). While all the solutions were effective in terms of biofilm removal, HOCl was superior to CA in terms of immersion ( p < 0.01), whereas CA was the most effective in terms of rubbing, outperforming both HOCl and CHX ( p < 0.01). CONCLUSIONS In conclusion, HOCl presents a reliable decontamination protocol for titanium surfaces, effectively eliminating microbial biofilms without compromising the integrity of the implant surface.