Jason Kum’s research while affiliated with Indiana University Indianapolis and other places

Background: Peri-implantitis treatments are mainly based on protocols for teeth but have not shown favorable outcomes for implants. The potential role of titanium dissolution products in peri-implantitis necessitate the consideration of material properties in devising treatment protocols. We assessed implant cleaning interventions on 1) bacterial removal from titanium-bound biofilms, 2) titanium surface alterations and related titanium particle dissolution, and 3) cytocompatibility. Methods: Acid-etched titanium discs were inoculated with human peri-implant plaque biofilms and mechanical antimicrobial interventions were applied on the titanium-bound biofilms for 30 seconds each: 1) Rotary nylon brush; 2) Titanium brush; 3) Water-jet on high and 4) low, and compared to sterile, untreated and Chlorhexidine-treated controls. We assessed CFU counts, biofilm removal, surface changes via SEM and AFM, and titanium dissolution via light microscopy and ICP-MS. Biological effects of titanium particles and surfaces changes were assessed using NIH/3T3 fibroblasts and MG-63 osteoblastic cell lines, respectively. Results: Sequencing revealed that the human biofilm model supported a diverse biofilm including known peri-implant pathogens. Water-jet and Nylon brush were most effective in reducing CFU counts (p<0.01 vs. control), while Chlorhexidine was least effective; biofilm imaging results were confirmatory. Titanium brushes led to visible streaks on the treated surfaces, reduced corrosion resistance and increased titanium dissolution over 30 days of material aging as compared to controls, which increase was amplified in the presence of bacteria (all p-val<0.05). Titanium particles exerted cytotoxic effects against fibroblasts, while surfaces altered by titanium brushes exhibited reduced osteoconductivity versus controls (p<.05). Conclusions: Present findings support that mechanical treatment strategies selected for implant biofilm removal may lead to titanium dissolution. Titanium dissolution should become an important consideration in the clinical selection of peri-implantitis treatments and a necessary criterion for the regulatory approval of instruments for implant hygiene. This article is protected by copyright. All rights reserved.