The antimicrobials incorporated in the resilient materials inhibited fungal growth during 14 days, with lower MICs for nystatin and chlorhexidine.

BackgroundAgeing leads to a decline in the function of the immune system, increasing the body's susceptibility to infections through the impairment of T-cells, macrophages, neutrophils and dendritic cells Denture stomatitis is a primary oral disease affecting elderly denture wearers. The major etiologic factor involved in this pathology is the infection by Candida albicans, an opportunistic pathogen that causes local and disseminated diseases in immunosuppressed humans. Neutrophils play a critical role in the immune response against C. albicans and are continually present in the salivary fluid and in the blood. The aim of this study was to determine ageing-related changes in salivary and blood neutrophils and their potential implications in Candida-related denture stomatitis.ResultsOur results showed a lower number of neutrophils in the saliva from patients presenting Candida-related denture stomatitis in comparison to their matched controls. Furthermore, fewer neutrophils were isolated from the saliva of aged control individuals in comparison to matched younger subjects. CXCR1, CD62L and CD11b expression were significantly greater on systemic neutrophils from younger control individuals. Elderly individuals showed more apoptotic salivary neutrophils and lower GM-CSF levels than younger ones, regardless of the occurrence of Candida infection. On the other hand, CXCL-8 concentrations were higher in the saliva from elderly individuals. Besides, TNF-α was detected at elevated levels in the saliva from infected elderly subjects. Salivary neutrophils from elderly and young patients presented impaired phagocytic activity against C. albicans. However, just systemic neutrophils from elderly showed decreased phagocytosis when compared to the younger ones, regardless of the occurrence of infection. In addition, neutrophils from aged individuals and young patients presented low fungicidal activity.ConclusionThe data suggests that the Candida related-denture stomatitis is associated to neutrophils function deficiency, and ageing drastically appears to alter important characteristics of such cells, facilitating the establishment of this infection.

The ability of Candida albicans to form biofilms on denture surfaces is a significant cofactor in the pathogenesis of denture stomatitis. In this study, we applied a differential staining approach and scanning electron microscopy (SEM) to analyse the effect of sodium hypochlorite and chlorhexidine gluconate on the viability, removal and morphology of C. albicans forming biofilms on denture acrylic using an in vitro model. Immediately after treatment, to distinguish live from dead C. albicans cells in the remaining biofilms, the specimens were stained differentially and analysed by confocal scanning laser microscopy. Moreover, morphological alterations of fungal cells were investigated using scanning electron microscopy. All disinfectant solutions killed all remaining fungal cells on the specimens. Interestingly, 4% chlorhexidine did not remove these cells from the acrylic resin surface whereas sodium hypochlorite solutions (1% and 2%) provided almost complete biofilm removal. Furthermore, treating the specimens with sodium hypochlorite induced cell morphology alterations, as seen in the residual fungal cells. Finally, according to our findings, it can be suggested that sodium hypochlorite solutions are the first choice as denture cleanser when compared with 4% chlorhexidine because those solutions not only killed C. albicans biofilms but also removed them from the heat-polymerised acrylic resin.

Equisetum giganteum L. (E. giganteum), Equisetaceae, commonly called “giant horsetail,” is an endemic plant of Central and South America and is used in traditional medicine as diuretic and hemostatic in urinary disorders and in inflammatory conditions among other applications. The chemical composition of the extract EtOH 70% of E. giganteum has shown a clear presence of phenolic compounds derived from caffeic and ferulic acids and flavonoid heterosides derived from quercitin and kaempferol, in addition to styrylpyrones. E. giganteum, mainly at the highest concentrations, showed antimicrobial activity against the relevant microorganisms tested: Escherichia coli, Staphylococcus aureus, and Candida albicans. It also demonstrated antiadherent activity on C. albicans biofilms in an experimental model that is similar to dentures. Moreover, all concentrations tested showed anti-inflammatory activity. The extract did not show cytotoxicity in contact with human cells. These properties might qualify E. giganteum extract to be a promising alternative for the topic treatment and prevention of oral candidiasis and denture stomatitis.

ObjectiveChemical solutions have been widely used for disinfection of dentures, but their effect on color stability of denture tooth acrylic resins after repeated procedures is still unclear. The aim of this in vitro study was to evaluate whether repeated cycles of chemical disinfectants affected the color stability of two denture tooth acrylic resins. Material and MethodsSixty disc-shaped specimens (40 mm x 3 mm) were fabricated from two different brands (Artiplus and Trilux) of denture tooth acrylic resin. The specimens from each brand (n=30) were randomly divided into 6 groups (n=5) and immersed in the following solutions: distilled water (control group) and 5 disinfecting solutions (1% sodium hypochlorite, 2% sodium hypochlorite, 5.25% sodium hypochlorite, 2% glutaraldehyde, and 4% chlorhexidine gluconate). Tooth color measurements were made by spectrophotometry. Before disinfection, the initial color of each tooth was recorded. Further color measurements were determined after subjecting the specimens to 7, 21, 30, 45, 60, and 90 immersion cycles in each tested solution. Color differences (ΔE*) were determined using the CIE L*a*b* color system. Data were analyzed using two-way repeated measures analysis of variance (ANOVA) followed by Tukey tests. The significance level was set at 5%. ResultsThere were statistically significant differences in ΔE* among the 5 disinfectants and water during the 90 cycles of immersion for both denture tooth acrylic resins. Distilled water promoted the greatest color change in both denture tooth acrylic resins, nevertheless none of tested disinfectants promoted ΔE* values higher than 1.0 on these acrylic materials during the 90 cycles of disinfection. ConclusionsRepeated immersion cycles in disinfecting solutions alter ∆E* values, however these values do not compromise the color of the tested denture tooth acrylic resins because they are imperceptible to the human eye.

Candida albicans is considered the most important Candida species able to cause oral infections in denture wearers. In recent years, Candida dubliniensis has emerged as a pathogenic yeast in humans. The close phenotypic similarities of C. albicans and C. dubliniensis have led to the misidentification of these species. In this work, our aim was to verify through PCR the presence of C. dubliniensis in palate and maxillary denture samples from 112 denture wearers presenting with or without denture-related stomatitis (DRS). C. dubliniensis was isolated at low rates from both palate (5.3 % and 10.7 %) and maxillary denture (5.3 % and 8.9 %) samples from wearers regardless of the presence of the disease. However, when C. dubliniensis was detected in individuals with DRS, it was always associated with C. albicans. In addition, our results showed that C. albicans was the most commonly identified candidal species in maxillary denture and hard palate samples from DRS patients (78.5 % and 89.2 %, respectively) as well as from controls (31.2 % and 28.5 %, respectively). In conclusion, C. dubliniensis was detected in the oral environment of denture wearers. The association of C. dubliniensis with C. albicans occurred in approximately 10 % of the DRS cases. INTRODUCTIONDenture-related stomatitis (DRS) is a local recurring disease (Budtz-Jorgensen et al., 1975;Dar-Odeh & Shehabi, 2003) that attacks the mucosal area subjacent to dental prostheses, beneath the fitting surface of the denture, especially maxillary dentures. Many studies have discussed the involvement of Candida albicans in the establishment and persistence of such disease since the acrylic denture fitting surfaces seem to facilitate the adherence of this micro-organism (Webb et al., 1998;Makihira et al., 2002;Ramage et al., 2004;Moura et al., 2006). Non-albicans Candida species can also be obtained from DRS lesions (Figueiral et al., 2007).Recently, a newly identified Candida species has emerged, Candida dubliniensis, which exhibits numerous characteristics typical of C. albicans species, including the formation of green colonies on CHROMagar medium. Both microorganisms share several phenotypic traits such as the ability to form true germ tubes, adhere to epithelial surfaces, secrete a range of aspartic proteinases and form chlamydospores (Martinez et al., 2002;Sullivan & Coleman, 1998;Sahand et al., 2005; Gilfillan et al., 1998). C. dubliniensis was first obtained from oropharyngeal lesions of human immunodeficiency virus (HIV)-positive patients (Sullivan & Coleman, 1998). Diabetic HIV-negative individuals also exhibited a high prevalence of C. dubliniensis in oral carriage and disease states (Willis et al., 2000). Recent work has documented the presence of C. dubliniensis in just one case of DRS lesion (Mosca et al., 2005). The association between C. dubliniensis and DRS suggests that this microorganism may play important roles in the establishment and persistence of DRS.Therefore, in this work, we examined the presence of C. dubliniensis in samples from palate ...

The results showed a coincidence between SAP expression and clinical, microscopic, and blood data. Finally, the molecular findings were consistent with the virulence capacities of C. albicans from biofilm formed on the denture resin, which possibly allowed epithelial invasion by the fungus.

Salivary immunity in elderly individuals presented with Candida-related denture stomatitisObjectives: Elderly individuals with Candida-related denture stomatitis (DS) present with a reduced defence against Candida albicans. This study evaluated levels of antimicrobial mediators in the elderly DS saliva and salivary neutrophils' activation characteristics compared with elderly and young without DS. Methods: Salivary peroxidases (SPO) and elastase activities (ELA), nitric oxide (NO), transforming growth factor beta (TGF-b), IL-6 and CCL3 production were determined in saliva from elderly with or without DS, and young control individuals. TLR4, CXCR1, CD11b, CD16 and CD32 expression on salivary neutrophils were evaluated. Correlations between number and apoptosis rate of salivary neutrophils, enzymatic activities and cytokine levels were determined. Results: Elderly DS individuals exhibited the lowest SPO and ELA activities. Also, the activity of both enzymes was low in elderly without DS. Although both elderly groups showed higher salivary NO and TGF-b levels compared to young control groups, elderly DS presented the highest salivary NO, TGF-b, IL-6 and CCL3 levels. Decreased percentages of salivary TLR4 + and CD16 + neutrophils were detected in both elderly groups. Although these damages could influence the establishment and persistence of DS, the highest levels of salivary IL-6 and CCL3 in elderly DS could be preventing more serious complications.