Influence of the use of complete denture adhesives on microbial adhesion and biofilm formation by single- and mixed-species

Abstract

ObjectivesTo verify whether the Ultra Corega Cream and Corega Strip Denture Adhesive adhesives interfere in the microbial adhesion and biofilm formation by Candida albicans and Lactobacillus casei in single- and mixed-species settings, and observe whether synergistic or antagonistic relationships between these species occur.MethodsSpecimens made from heat-polymerized acrylic resin (Lucitone 550) were fabricated (n = 144) with a circular shape and standardized roughness (3.0 μm ±0.3 Ra) and were divided into three groups: Without Adhesive (WA), with Ultra Corega Cream adhesive (CA) and Corega Strips adhesive (SA). These groups were divided into three subgroups each: C. albicans single-species, L. casei single-species and C. albicans with L. casei (mixed-species). Microbial adhesion and biofilm formation assays were performed in duplicate at four distinct experimental times (n = 8 per experimental condition). The amount of each microorganism on the surfaces of the specimens was observed by counting of the Colony Forming Units (CFU) per substrate. Additional specimens were characterized by Scanning Electron Microscopy (SEM), with 18 specimens being used in this analysis (n = 18), 2 per experimental condition (n = 2). Two-way ANOVA and Tukey’s test for multiple comparisons were employed, using α≤0.05.ResultsL. casei (mixed-species) adhered more on the WA substrate than the CA, while C. albicans (single- and mixed-species) adhered more on the SA. C. albicans, both single- and mixed-species adhered more than the L. casei (single- and mixed-species), regardless of the substrate. L. casei (single-species) formed more biofilm on the WA, but in its mixed cultivation, it had no difference of growth among the tested situations. C. albicans (single- and mixed-species) formed more biofilm on the SA than the CA, and the fungus formed more biofilm when compared to L. casei. In general, whenever a species was compared in its single- and mixed-species situation, no statistically significant difference was observed. SEM of biofilm formation assays demonstrated that L. casei single-species WA formed more biofilm than when the adhesives tested were used, and C. albicans (both single- and mixed-species) formed more biofilm on the SA than on the CA.Conclusions(1) The two denture adhesives tested increased the adhesion of C. albicans but not of L. casei; (2) biofilm formation by C. albicans (single- and mixed-species) was increased on the SA; (3) Relations of synergism or antagonism was not observed between the two microorganisms studied.

Candida spp./Bacteria Mixed Biofilms

“…In fact, C. albicans biofilm formation by (single-and mixed-species) was higher on the strip adhesive. The authors did not observe any relations of synergism or antagonism between the two microorganisms [103].…”

Evaluation of Candida albicans biofilm formation on conventional and computer-aided-design/computer-aided manufacturing (CAD/CAM) denture base materials

“…According to various laboratory studies, C. albicans is the most frequently isolated strain that can adhere and form biofilms on the oral mucosa and subsequently cause denture stomatitis [ 22 , 23 ]. Over the decades, many efforts have been made to improve the material, the curing techniques, and the processes used for fabricating denture bases [ 10 , 15 ].…”

“…Based on previous studies, there is an association between the characteristics of the denture acrylic surface and the amount of Candida colonization, followed by biofilm formation [ 10 , 11 ]. Other studies have also confirmed that surface roughness, porosity, and permeability can affect Candida colonization and biofilm formation on the removable denture acrylic surface [ 12 , 13 ].…”

Microbial adhesion and biofilm formation by Candida albicans on 3D-printed denture base resins

“…After incubation (37° C for 16 hours), the cultures were diluted 1:10 in TYE medium + 1% glucose and the initial optical density (OD) at 540nm was read in a spectrophotometer (CMC Laboratório Ltda., Brazil). The period corresponding to the midlog growth phase was approximately 8 h with OD 540nm = 1.07(±0.07) and microbial concentration of 2.31×10 7 (±3.55×10 6 ) CFU/mL [ 36 ].…”

“…The solution was centrifuged (4°C, 4000RPM, for 10 minutes—Centrifuge 5810R, Eppendorf, Hamburg, Germany) and the supernatant (clarified saliva) was filtered using a 0.22μm polyethersulfone membrane filter (Rapid Flow, Nalgene, Thermo Fisher Scientific, Waltham, Massachusetts, USA). Aliquots of saliva were kept at -80°C until use [ 36 ].…”