In-vitro evaluation of the effectiveness of various disinfection procedures in reducing biofilm formation on customized implant abutments of different designs

To investigate the effectiveness of 80% ethanol and 2% chlorhexidine gel in reducing Pseudomonas aeruginosa (P. aeruginosa) biofilm formation on different types of customized implant abutments, using the crystal violet staining method. Three types of implant abutments were tested: Ti-base, monoblock titanium, and zirconia hybrid abutment. A total of 84 abutments were prepared and divided into four groups for each abutment type (n = 7): negative control (no biofilm), positive control (biofilm, no disinfection), ultrasonic cleaning with 80% ethanol for 5 min, and immersion in 2% chlorhexidine gel for 10 min. All abutments were incubated with P. aeruginosa for 24 h. Biofilm formation was quantified using the crystal violet staining method, and bacterial adhesion was confirmed in the positive control group via scanning electron microscopy. Statistical analysis was performed using one-way ANOVA and Tukey's test. There was no significant difference in bacterial retention among the different abutment designs tested (p > 0.05). The analyses revealed that both cleaning methods significantly reduced biofilm formation in all abutment types (p < 0.05) but were not superior to each other (p > 0.05). Both ethanol- and chlorhexidine-based disinfection protocols were effective in reducing Pseudomonas aeruginosa biofilm formation on different abutment designs under in-vitro conditions.