Evaluation of biofilm formation, adhesive strength and effectiveness of cleaning protocols on adhesive-containing acrylic resin specimens: An in vitro study.

BACKGROUND

Denture adhesives promote greater stability and retention of dentures. However, they can also facilitate biofilm formation related to oral diseases.

OBJECTIVES

The study aimed to evaluate the influence of 2 adhesives on the microbial load of mixed biofilm and adhesive strength. Additionally, the objective was to assess the effect of 3 hygiene protocols on the microbial load and cell metabolism of this biofilm.

MATERIAL AND

METHODS

The study compared Corega Ultra Cream (CCA) and OlivaFix® Gold (OFA) adhesives by evaluating the biofilm formation of Candida albicans, Candida glabrata, Staphylococcus aureus, and Streptococcus mutans by colony-forming unit (CFU), as well as adhesive strength. The implemented hygiene protocols included brushing and immersion in water (BW), 0.15% triclosan (BT0.15%), or 0.25% sodium hypochlorite (BSH0.25%). The control groups were either without adhesive (CG) or without any hygiene protocols (CGwH). The one-way and two-way analyses of variance (ANOVAs) with Tukey's post hoc test and a generalized linear model with Bonferroni adjustment were used for statistical analysis (α = 0.05).

RESULTS

The microbial load of C. albicans was higher when OFA was used (p < 0.001). The microbial loads of C. glabrata and S. mutans were similar between adhesives and higher in the CG (p < 0.001). The influence of the adhesives on the microbial load of S. aureus was not statistically significant (p = 0.287). The adhesive strength promoted by OFA was greater and more stable than when CCA was used (p = 0.007). The immersion in sodium hypochlorite led to a reduction in the microbial load of C. albicans (p < 0.001), C. glabrata (p = 0.002) and S. mutans (p = 0.012), independent of the adhesive. For S. aureus, the microbial load was lower with OFA/BSH0.25% (p = 0.022). All hygiene protocols resulted in a decreased cell metabolism when compared to the CGwH (p < 0.001).

CONCLUSIONS

Brushing with BSH0.25% solution was the most effective hygiene protocol, resulting in a reduction in the microbial load and metabolism. This protocol may be recommended as a first-line option for the disinfection of dentures.