An In Situ Model for Biofilm Formation on Titanium Implants

Methods: Neoss Bimodal threaded titanium implants were mounted into custom-made vacuum-formed removable oral appliances configured with the implant horizontal on the buccal surface of mandibular first molar teeth. The implants were fixed into position by their healing abutment screws to prevent them from being dislodged during normal movements of the buccal mucosa. Variations in design including use of PVC tubing allowed variations in salivary contact and oxygen tension to achieved. Appliances were worn continuously for 48 hours, being removed temporarily during eating and oral hygiene procedures. Biofilms were stained using 3 tone disclosing solution, then fixed and assessed using SEM.

Results: Designs with the implant enclosed in a PVC tube showed rapid formation of dense biofilms over 48 hours. These biofilms contained water channels and large numbers of facultative and anaerobic bacteria, with the typical three dimensional configuration of dental plaque biofilms across the surface of the implant, including the region of the threads. There were no significant adverse effects experienced from wearing the appliances.

Conclusions: This in situ model generates a biofilm representative of dental plaque and will be useful for evaluating different methods of debridement both intra-orally and on the bench.
Implants for this study were provided by Neoss.