In vitro study of biofilm formation and effectiveness of antimicrobial treatment on various dental material surfaces

Abstract

Elevated proportions of Candida albicans in biofilms formed on dentures are associated with stomatitis whereas Streptococcus mutans accumulation on restorative materials can cause secondary caries. Candida albicans, S. mutans, saliva-derived and C. albicans/saliva-derived mixed biofilms were grown on different materials including acrylic denture, porcelain, hydroxyapatite (HA), and polystyrene. The resulting biomass was analysed by three-dimensional image quantification and assessment of colony-forming units. The efficacy of biofilm treatment with a dissolved denture cleansing tablet (Polident(®)) was also evaluated by colony counting. Biofilms formed on HA exhibited the most striking differences in biomass accumulation: biofilms comprising salivary bacteria accrued the highest total biomass whereas C. albicans biofilm formation was greatly reduced on the HA surface compared with other materials, including the acrylic denture surface. These results substantiate clinical findings that acrylic dentures can comprise a reservoir for C. albicans, which renders patients more susceptible to C. albicans infections and stomatitis. Additionally, treatment efficacy of the same type of biofilms varied significantly depending on the surface. Although single-species biofilms formed on polystyrene surfaces exhibited the highest susceptibility to the treatment, the most surviving cells were recovered from HA surfaces for all types of biofilms tested. This study demonstrates that the nature of a surface influences biofilm characteristics including biomass accumulation and susceptibility to antimicrobial treatments. Such treatments should therefore be evaluated on the surfaces colonized by the target pathogen(s).

Therapeutic Potential of Thiazolidinedione-8 as an Antibiofilm Agent against Candida albicans

“…Several virulence factors that contribute to the development of candidal infection have been identified. They include (i) adhesins that allow adhesion to human cells with subsequent invasion [5], (ii) the ability to form biofilm on human mucosa [5] and on artificial surfaces such as catheters [6], [7] and dental devices [8], [9], and (iii) the ability to switch from yeast to hyphal form [10]. Biofilm formation is an important factor in C. albicans pathogenesis [11]; it involves attachment, colonization and the development of a mature biofilm structure composed of yeast, pseudo- and true hyphae, and extracellular matrix [11]–[14].…”

Cranberry proanthocyanidins inhibit the adherence properties of Candida albicans and cytokine secretion by oral epithelial cells

“…Several virulence properties of C. albicans , which contribute to the development of oral candidiasis have been identified. They include i) adhesins that allow these organisms to adhere to oral epithelial cells with subsequent invasion [3], ii) the capacity to form biofilm on both oral mucosa and denture devices [4,5], and iii) the ability to switch from yeast form to mycelium form [6]. …”

Managing Denture Biofilm Related Diseases

“…55 In addition, the materials used in the manufacture of dentures can also affect adherence and colonization by microbes, including C. albicans, as well as impact the efficacy of antimicrobial treatment on thebiofilm. 56 Soaking dentures in an appropriate commercial cleanser has been shown to be effective in removing attached microbes without increasing surface roughness. 57 Overnight denture removal is also important for controlling denture plaque, as it isolates the denture from salivary secretion that provides nutrients for microbial growth of denture biofilm.…”