Long-term efficacy of denture cleansers in preventing Candida spp. biofilm recolonization on liner surface

Abstract

This study evaluated the long-term efficacy of denture cleansers against Candida spp. biofilm recolonization on liner surface. Specimens were fabricated of a poly(methyl methacrylate)-based denture liner and had their surface roughness evaluated at baseline and after cleansing treatments. C. albicans or C. glabrata biofilms were formed on liner surface for 48 h, and then the specimens were randomly assigned to one of cleaning treatments: two alkaline peroxides (soaking for 3 or 15 min), 0.5% sodium hypochlorite (10 min) or distilled water (control; 15 min). After the treatments, the specimens were sonicated to disrupt the biofilm, and residual cells were counted (cell/mL). Long-term effectiveness of the cleaning processes was determined by submitting a set of cleaned specimens to biofilm growth conditions for 48 h followed by estimation of cell counts. The topography of specimens after cleaning treatments was analyzed by SEM. Data were analyzed by ANOVA and Tukey's test (α; = 0.05). Results of cell count estimation showed significant differences in cleanliness among the treatments (p < 0.001), and it could be observed by SEM. However, no significant difference (p > 0.05) was observed among the Candida species regarding the recolonization condition. Alkaline denture cleansers showed similar cleaning performance and both differed from the control (p < 0.001). Sodium hypochlorite was the only treatment that removed biofilm efficiently, since no viable cells were found after its use. In conclusion, alkaline peroxide denture cleansers were not effective in removing Candida spp. biofilm from denture liner surfaces and preventing biofilm recolonization.

Antifungal activity of components used for decontamination of dental prostheses on the growth of Candida albicans

“…The results of this study confirm the antifungal potential of peroxide-based chemical cleaners, sodium hypochlorite and the antimicrobial-based mouthwash solutions containing chlorhexidine and essential oils, which corroborate the findings from other studies 8,9,12,18 . Although other studies have widely evaluated the antimicrobial potential of these solutions against mature biofilms, the results of the present study suggests that these substances are capable of inhibiting biofilm formation.…”

“…Topical antifungal medications, such as Nystatin and Myconazol, are recommended for the treatment of oral candidiasis, especially when associated with the use of dentures 5,7 . The use of cleaning solutions for prostheses is also recommended 5,[7][8][9] , however, they are generally only used in patients who have difficulties in maintaining the cleanliness of their dentures [10][11][12] .…”

“…Patients with motor difficulties or inadequate mechanical hygiene are recommended to use adjuvant cleaning solutions 1,2,[10][11][12] , such as sodium hypochlorite, chlorhexidine digluconate, alkaline peroxides and enzymatic agents [8][9][10][11][12] . The objective of these solutions is to remove the biofilm and to prevent recolonization.…”

“…They are chemical agents composed of alkaline detergents and oxygen-releasing agents, such as trisodium phosphate and sodium percarbonate or perborate, respectively. Alkaline peroxides are available as tablets or in powder and when in solution they change into hydrogen peroxide, which is able to primarily attack the organic components of the deposits present in prostheses 8,9 . However, these products have been shown to be ineffective at inhibiting Candida spp.…”

“…activity 8,9,12 , their routine use may bring some negative aspects, such as color change and lowered acrylic resistence 10,16 . The development of natural products with potential for clinical use is necessary to create new strategies to chemically control oral candidiasis, as well as to counteract the inconveniences of comercially available products 7 .…”