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

This study compared the effects of hypochlorous acid (HOCl) on titanium surface structure, biofilm removal, and biofilm formation with those of other decontamination agents. In this in vitro study, HOCl, chlorhexidine gluconate (CHX), and citric acid (CA) were applied to sterile, smooth titanium disks that mimic titanium abutments using rubbing and immersion methods for 8 min. 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 using a spectrophotometer. 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 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). In conclusion, HOCl presents a reliable decontamination protocol for titanium surfaces, effectively eliminating microbial biofilms without compromising the integrity of the implant surface.