Novel technique using cold atmospheric plasma coupled with air-polishing for the treatment of titanium discs grown with biofilm: An in-vitro study

Objectives: The aim of the present study was to assess the decontamination efficacy and titanium surface alterations of erythritol based air abrasion (AA) and cold atmospheric plasma (CAP) targeting a human complex biofilm. Methods: Saliva collected from a peri-implantitis patient was used to develop in vitro human biofilm over titanium discs with machined (group A) and moderately rough (group B) surface. The discs were treated with AA, experimental CAP or a combination of both treatments (COM). The amount of biofilm on the discs was measured by crystal violet (CV). Surface features and roughness before and after treatment were assessed by SEM and laser profilometry, respectively. The data were statistically analyzed using Kruskal Wallis followed by Dunn's multiple comparison test after being checked for normality by Shapiro-Wilk test. Results: All the discs in group A performed better to treatments compared to group B. In both groups, CV data showed significantly lower amount of biofilm after AA treatment compared to CAP (p < 0.05). Cleaning efficacy revealed relevant decontamination of both the surfaces following AA and COM treatments and almost complete biofilm removal after AA application on group A (99.92%). SEM analysis demonstrated no post-treatment alterations on the discs and laser profilometry did not show statistically significant changes in S_a and S_dr values. Significance: Decontamination with AA delivering erythritol with or without CAP is highly effective in biofilm removal from different titanium surfaces. All the tested treatments, including CAP showed no noticeable alterations of the titanium discs surface features. Further in vivo studies are necessary to understand the potential of CAP technology in implant surface decontamination.