Development of a New Bioadhesive Gel in the Prevention of Bacterial Biofilms on Dental Implants: An In Vitro Study

Peri-implantitis is a reality that clinicians face in their daily practice. Current evidence discusses the applicability of bacteriostatic or bactericidal methods in order to minimize the colonization of bacteria, which entails controversy. In this scenario there arises a need to develop surfaces that minimize bacteria's appetite for them.

An in vitro microbiological study was conducted to assess the effect of a chlorhexidine-based bioadhesive gel on the growth and adhesion of a simplified peri-implantitis-associated microbial consortium. Grade IV titanium disks with three surface types (machined, sandblasted, and ContacTi) were incubated with the consortium under anaerobic conditions for 10 days, with and without gel treatment. Microbial viability was evaluated by colony-forming unit (CFU) counts, and biofilm structure was analyzed by scanning electron microscopy. Microbial community composition was assessed using 16S rRNA gene amplicon sequencing.

After 10 days, gel-treated implants showed complete inhibition of cultivable microorganisms, with CFU values reduced below the detection limit on all surfaces, compared with untreated implants (p < 0.05). In untreated samples, ContacTi surfaces exhibited higher bacterial viability than machined and sandblasted surfaces. Metataxonomic analysis revealed a marked reduction in peri-implant pathogens, particularly Porphyromonas gingivalis, whose relative abundance decreased from approximately 20% in the initial inoculum to ~1% after incubation.

The bioadhesive gel demonstrated a quantitatively significant antimicrobial effect, preventing biofilm formation on all tested implant surfaces after 10 days.