Efecto sinérgico antimicrobiano de la terapia fotodinámica y el quitosano en las biopelículas adheridas al titanio de Staphylococcus aureus, Escherichia coli y Pseudomonas aeruginosaun estudio in vitro

Résumé

Background: To date, no studies on the combined use of photodynamic therapy (PDT) and chitosan against peri-implantitis have been published. Purpose: To evaluate the possible synergistic antimicrobial effect of PDT and chitosan on the titanium-adherent biofilms of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa. Materials and Methods: A total of 60 titanium discs were included in this study. The discs were randomized into three bacterial contaminations (n=20 discs per bacterium). After being cultured (incubated for 48 hours) they were randomized again into four different disinfection modalities (n=5 discs per treatment): control (without treatment), PDT, chitosan 3 mg/ml, and PDT + chitosan 3 mg/ml. After the treatments, the colony forming units (CFU) were measured to determine antimicrobial effects, and field emission scanning electron microscopy (FESEM) was used to study cell morphology and titanium adherence. Results: For all the evaluated bacteria and all the variables studied the order from highest to lowest antimicrobial effectiveness was: PDT + chitosan 3 mg/ml>chitosan 3 mg/ml>PDT>control. Although, all disinfection methods were significantly effective when compared to control, the combined treatment of PDT + chitosan 3 mg/ml had the greatest antimicrobial effect against the three studied bacteria. Conclusions: The combination of PDT and chitosan has a synergistic antimicrobial effect against the bacteria S. aureus, E. coli and P. aeruginosa, all closely related to peri-implantitis.