Effect of sodium bicarbonate on Candida albicans adherence to thermally activated acrylic resin

Effect of Denture Wearing on Occurrence of Fungal Isolates: An Original Study

The present study aimed to evaluate the effect of denture wearing on the occurrence of fungal isolates in the oral cavity before and after complete denture insertion. Fifty completely edentulous patients were selected. Swab samples were collected intraorally before the fabrication of complete dentures from the palatal mucosal surface and after complete denture fabrication (1 and 7 days after denture insertion). Further, these samples were inoculated and incubated. Results showed that in 48 patients, no isolate of fungus before denture insertion was found. In two subjects, results were false positive (contamination from the environment), and in six patients, there was an increase in growth, but not much significant increase of growth was seen (mild growth of fungus only after denture insertion). One of the major findings of this study was that the overall occurrence of fungal isolates (before and after denture insertion) in the oral cavity was not significant.

Prevention and the treatment of oral mucositis: the efficacy of sodium bicarbonate vs other agents: a systematic review

INTRODUCTION

Oral mucositis (OM) is a major side effect of cancer therapy, which is associated with significant symptoms, treatment delays and increased costs for the health system. It is an important component of the quality of life of cancer patients and, until now, there has been no gold standard regarding prevention or treatment of this pathology. Notwithstanding the paucity of treatment guidelines (due to limited evidence from high-quality, rigorous studies), sodium bicarbonate (SB) rinses are one of the most used agents for OM management.

OBJECTIVES

A systematic review (2000-2022) was performed in order to compare and examine different agents versus sodium bicarbonate (SB) in preventing or treating OM.

SOURCES

Eleven randomized controlled trials (RCT) were evaluated: four were conducted for the prevention and seven for the management of OM. The risk of bias of RCTs was assessed using the revised Cochrane risk of bias tool for randomized trials.

STUDY SELECTION

According to the RoB2 evaluation for randomized trials, four RCTs were judged to be at a high risk of bias, two were rated as 'problematic', while five were deemed to be a low risk of bias.

CONCLUSIONS

The results revealed that there was no evidence for supporting SB in OM treatment regarding management and prevention.

CLINICAL SIGNIFICANCE

Results showed in this review takes on a strategic importance in the use of SB for OM management or prevention; indiscriminate use of SB could be counterproductive because it causes a sudden pH increase and it delays proper OM pharmacological treatment.

Anti-fungal efficacy of Miswak Extract (Salvadora Persica) and commercial cleaner against Candida albicans on heat cured polymethylmethacrylate denture base

AIM

The aim of the study was to compare the antifungal efficacy between commercial cleaner (Corega) and Miswak extract (Salvadora persica) against Candida albicans on heat cured Polymethyl methacrylate (PMMA) acrylic denture base resin.

MATERIALS AND METHODS

Forty-eight samples of heat cured PMMA acrylic denture base resin were fabircated in the study. The sterile acrylic resin specimens were immersed in standardized cell suspension of Candida albicans and incubated for 60 min at 370°C for cell adhesion and 2 h at 370°C for biofilm formation. After 24 h biofilm was evaluated by cell viability (CFUs) on SDA and cell counting of Candida albicans under light microscope at 400× magnification. The fungicidal effect of commercial cleaner and Miswak extract on Candida albicans biofilm was then evaluated by colony-forming units on SDA and cell counting under light microscope at 400× magnification.

RESULTS

Screening test agar disk-diffusion assay showed mean inhibitory zone of 3 mm for commercial cleaner as compared to Miswak extract, which showed mean inhibitory zone of 2 and 1 mm for different concentrations. Broth microdilution method showed 31 mg/ml MIC and 62.5 mg/ml Minimal Fungicidal Concentration (MFC) values for commercial cleaner as compared to Miswak extract that showed 125 mg/ml MIC and 250 mg/ml MFC values against Candida albicans. A significant difference (p < 0.05) was observed between pre and post treatment of both commercial cleaner and Miswak extract, for CFUs and cell count for Candida albicans.

CONCLUSION

Commercial denture cleaner (Corega) showed better antifungal (C albicans) activity than Miswak extract (Salvadora persica) on heat cured PMMA acrylic denture base resin.

Sodium bicarbonate gels: a new promising strategy for the treatment of vulvovaginal candidosis

Vulvovaginal candidosis (VVC), caused mainly by the yeast Candida albicans, is the second most prevalent vaginal infection. It has been found to have a large impact on women's quality of life, self-esteem and routines. The prevalence of recurrent vulvovaginal candidosis (RVVC) remains high so the development of alternative treatments is needed. The main objective of this study was to develop and characterize sodium bicarbonate gels to treat VVC. We described key formulation characteristics and analyzed their influence on in vitro performance evaluations. The potential to inhibit Candida albicans's growth, the pH, osmolality, viscosity and rheological performance in contact with vaginal fluid simulant and the bioadhesion's profile (using a vaginal ex vivo porcine model) were studied for all formulations. Among the formulations, formulation C (5% sodium bicarbonate, 1% carbomer and 94% water) was the most effective in inhibiting the C. albicans' growth. This gel presented the same potential (the same MIC 2.5%) to inhibit other etiological agents of VVC (C. glabrata, C. krusei, C. tropicalis and C. parapsilosis) for all species tested. Additionally, sensorial characteristics of gel C were in accord with users' preferences. This gel exhibited physicochemical characteristics acceptable for short term treatments, suggesting good overall performance for the treatment of VVC. Furthermore, Gel C was biocompatible with the HeLa cell line (MTT assay) and was classified as a non-severe irritant in the HET-CAM assay (irritation score 4 ± 1). Overall, gel C was deemed the best performing of the set tested, and suitable for further development.

Effects of two peroxide enzymatic denture cleaners on Candida albicans biofilms and denture surface

Objective

To compare the antifungal action of two commercially available denture cleaning agents to that of standard clinical solutions, and determine their effects on the polymethyl methacrylate (PMMA) acrylic resin denture surface.

Methods

Candida albicans growth was analyzed by colony forming assay, and the methyl thiazolyl tetrazolium (MTT) assay was used to evaluate biofilm formation and cell adhesion. The morphology and roughness of PMMA acrylic resin surface was measured by scanning electron microscopy (SEM) images and stylus method.

Results

Clene®, Polident® and 3% NaHCO₃ solutions showed significantly greater antifungal effects in terms of both inhibiting growth and biofilm formation. In addition, Clene® solution prevented adhesion of C. albicans on cell culture plates compared to filter-sterile tap water, whereas other reagents did not have an inhibitory effect. One-month immersion in the different cleaning reagents significantly inhibited fungal adhesion on the PMMA surface Clene®, Polident® and 3% NaHCO₃ showed greater effect compared to PBS and filter-sterile tap water. Finally, none of the cleansing agents significantly affected the morphology and roughness of the PMMA surface.

Conclusion

Clene®, Polident® and 3% NaHCO₃ solutions can inhibit C. albicans growth and biofilm formation to some extent on cell culture plates, and significantly inhibit fungal adhesion on the PMMA surface without affecting surface morphology and roughness.

Control of bacterial biofilms formed on pacifiers by antimicrobial solutions in spray

BACKGROUND

The aim was to evaluate the use of vinegar, hydrogen peroxide and sodium bicarbonate solutions for the disinfection of pacifiers.

DESIGN

Different types and concentrations of the substances were screened in planktonic and biofilm for antimicrobial activity on Streptococcus mutans, Staphylococcus pyogenes, Staphylococcus aureus and Escherichia coli. Also, the effect of the most effective substance was tested against polymicrobial biofilms aiming to mimic the multispecies colonization found in a pacifier.

RESULTS

Based on the agar diffusion test, minimal inhibitory concentration (MIC) and minimal microbicide concentration assays, 70% apple vinegar (70%AV) and 70% hydrogen peroxide (70%HP) were selected (P < 0.05). All tested solutions were able to significantly reduce viable cells of S. pyogenes, S. mutans and E. coli from the biofilms A statistically significant reduction of viable cells in S. aureus biofilms were observed after treatment with 70%AV in comparison to the other treatments. When compared to other microbial species, it was found that 70%HP was particularly effective against E. coli. The solution of 70%HP was able to reduce the viable cells of Enterobacteriaceae/pseudomonas of a polymicrobial biofilm formed from a pacifier. The other solutions were not effective in relation to control group.

CONCLUSION

Solutions of 70% HP showed to be a good alternative for chlorhexidine digluconate for the disinfection of pacifiers.

Chemical hygiene protocols for complete dentures: A crossover randomized clinical trial

STATEMENT OF PROBLEM

Clinical evidence on the best chemical protocol for the disinfection and removal of biofilm from complete dentures is lacking.

PURPOSE

The purpose of this crossover randomized clinical trial was to assess the effectiveness of various chemical hygiene clinical protocols in reducing the microbial viability of biofilm formed on complete dentures.

MATERIAL AND METHODS

In this triple-blind (participants, dentist, and outcome evaluator) study, complete denture wearers without candidiasis were randomly divided into 4 groups (n=40) according to the chemical hygiene protocol: water (placebo), 0.5% sodium hypochlorite solution, 0.12% chlorhexidine gluconate solution, and 5% sodium bicarbonate solution. The biofilm formed on the palate intaglio and denture teeth was collected and assessed in each experimental phase for quantitative microbial viability at the seventh and 14th day after using the chemical protocol.

RESULTS

Two participants were lost. Data were analyzed by MANOVA and Tukey HSD tests. Soaking dentures was not effective in decreasing Candida albicans, C. non-albicans, and lactobacillus counts. The use of sodium hypochlorite and chlorhexidine decreased total microorganisms and Streptococcus mutans counts for both palate and teeth compared with water and sodium bicarbonate. The intaglio of the dentures always presented higher microbial counts than did the denture teeth.

CONCLUSIONS

The use of sodium hypochlorite and chlorhexidine and mechanical cleansing with a toothbrush decreased microbial viability in healthy complete denture wearers.

Antibacterial, Hydrophilic Effect and Mechanical Properties of Orthodontic Resin Coated with UV-Responsive Photocatalyst

Photocatalysts have multiple applications in air purifiers, paints, and self-cleaning coatings for medical devices such as catheters, as well as in the elimination of xenobiotics. In this study, a coating of a UV-responsive photocatalyst, titanium dioxide (TiO₂), was applied to an orthodontic resin. The antibacterial activity on oral bacteria as well as hydrophilic properties and mechanical properties of the TiO₂-coated resin were investigated. ultraviolet A (UVA) (352 nm) light was used as the light source. Antibacterial activity was examined with or without irradiation. Measurements of early colonizers and cariogenic bacterial count, i.e., colony forming units (CFU), were performed after irradiation for different time durations. Hydrophilic properties were evaluated by water contact angle measurements. While, for the assessment of mechanical properties, flexural strength was measured by the three-point bending test. In the coat(+)light(+) samples the CFU were markedly decreased compared to the control samples. Water contact angle of the coat(+)light(+) samples was decreased after irradiation. The flexural strength of the specimen irradiated for long time showed a higher value than the required standard value, indicating that the effect of irradiation was weak. We suggest that coating with the ultraviolet responsive photocatalyst TiO₂ is useful for the development of orthodontic resin with antimicrobial properties.

Efficacy of Plantago major, chlorhexidine 0.12% and sodium bicarbonate 5% solution in the treatment of oral mucositis in cancer patients with solid tumour: A feasibility randomised triple-blind phase III clinical trial

PURPOSE

Oral mucositis is one of the most common adverse effects of chemotherapy and radiotherapy. The aim of this study was to compare the efficacy of Plantago major extract versus chlorhexidine 0.12% versus sodium bicarbonate 5% in the symptomatic treatment of chemotherapy-induced oral mucositis in solid tumour cancer patients.

METHOD

Multicentre randomised controlled trial estimated sample of 45 solid tumour patients with grade II-III mucositis. The participants were randomised to one of three treatments, consisting of sodium bicarbonate 5% aqueous solution together with: an additional dose of sodium bicarbonate 5% aqueous solution, Plantago major extract, or chlorhexidine 0.12%. The primary outcomes were severity of mucositis, pain intensity, oral intake capacity and quality of life. The independent variable was treatment group, and confounders included sociodemographic data, neutrophil count, chemotherapy drug and dose received.

RESULTS

Of the 50 patients enrolled, 68% (n = 34) achieved grade 0 mucositis (none), with those using the double sodium bicarbonate rinse healing in five days on average (95% CI 3.9, 6.5) versus seven days (95% CI 5.3, 9,0) for the chlorhexidine group and seven days (95% CI 5.3, 8.5) for the Plantago major group. The pain experienced by the participants lessened over the 14 days of treatment, but differences in pain intensity between the three groups did not show statistical significance (p = 0.762).

CONCLUSIONS

Healing time was shorter with the double sodium bicarbonate solution compared to the other two rinses, but the differences were not significant. Our results suggest it may be time to reconsider the use of Plantago major extract in the management of oral mucositis.

Use of alcohol vinegar in the inhibition of Candida spp. and its effect on the physical properties of acrylic resins

Background

Given the high prevalence of oral candidiasis and the restricted number of antifungal agents available to control infection, this study investigated the in vitro antifungal activity of alcohol vinegar on Candida spp. and its effect on the physical properties of acrylic resins.

Methods

Tests to determine the Minimum Inhibitory Concentration (MIC) and Minimum Fungicidal Concentration (MFC) of vinegar alcohol (0.04 g/ml of acetic acid) and nystatin (control) were performed. The antifungal activity of alcohol vinegar was assessed through microbial growth kinetic assays and inhibition of Candida albicans adhesion to acrylic resin at different intervals of time. Surface roughness and color of the acrylic resin were analyzed using a roughness meter and color analyzer device.

Results

Alcohol vinegar showed MIC_75% and MFC_62.5% of 2.5 mg/ml, with fungicidal effect from 120 min, differing from nystatin (p < 0.0001), which showed fungistatic effect. Alcohol vinegar caused greater inhibition of C. albicans adhesion to the acrylic resin (p ≤ 0.001) compared to nystatin and did not change the roughness and color parameters of the material.

Conclusion

Alcohol vinegar showed antifungal properties against Candida strains and caused no physical changes to the acrylic resin.

Antifungal Activity of Apple Cider Vinegar on Candida Species Involved in Denture Stomatitis

PURPOSE

To evaluate the in vitro antifungal activity of apple cider vinegar on Candida spp. involved in denture stomatitis.

MATERIAL AND METHODS

The microdilution technique was used to determine the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC) of apple cider vinegar containing 4% maleic acid, and nystatin (control). Further tests of microbial kinetics and inhibition of adherence to acrylic resin were performed testing different concentrations (MIC, MICx2, MICx4) of the products at time intervals of 0, 30, 60, 120 and 180 minutes. A roughness meter was used to measure the changes in surface roughness; color change of the acrylic resin specimens exposed to the test products in different concentrations and time intervals were also evaluated.

RESULTS

Apple cider vinegar (4%) showed MIC of 2500 μg/ml and MFC of 2500, 5000, and 10,000 μg/ml depending on the strain tested. Nystatin showed MIC of 3.125 μg/ml and strain-dependent MFC values ranging from 3.125 to 12.5 μg/ml. The microbial kinetic assay showed a statistical difference between apple cider vinegar and nystatin (p < 0.0001). After 30 minutes of exposure, apple cider vinegar showed fungicidal effect at MICx4, whereas nystatin maintained its fungistatic effect. Apple cider vinegar showed greater inhibition of adherence (p < 0.001) compared to control. Apple cider vinegar did not significantly alter the surface roughness of the acrylic resin specimens compared to nystatin (p > 0.05), and both had no influence on their color.

CONCLUSION

Apple cider vinegar showed antifungal properties against Candida spp., thus representing a possible therapeutic alternative for patients with denture stomatitis.

In Vitro Antimicrobial Activity of an Experimental Dentifrice Based on Ricinus Communis

This study evaluated the antimicrobial activity of a Ricinus communis-based experimental dentifrice for denture hygiene against the following standard strains: Staphylococcus aureus, Escherichia coli, Streptococcus mutans, Enterococcus faecalis, Candida albicans and Candida glabrata. The minimum inhibitory concentration (MIC) assay was performed with R. communis in pure oil at 2.5%. Only E. coli was not inhibited by R. communis, but the MIC (0.0781%) was effective against the other microorganisms. From these results it was determined the R. communis concentrations for experimental dentifrices, 1, 2, 5 and 10%, which were evaluated by the test-well diffusion in agar. The commercial dentifrices Colgate, Trihydral and Corega Brite were tested for comparative purposes. The diameter of the zones of bacterial growth inhibition produced around the wells was measured (in mm) with a rule under reflected light. Data were analyzed statistically by analysis of variance and Tukey's post-hoc test (α=0.05). Neither the commercial nor the experimental dentifrices were effective against E. coli. The experimental dentifrices containing R. communis at 2, 5 and 10% presented action against S. mutans, S. aureaus and E. faecallis. The experimental dentifrices showed no antimicrobial activity against Candida spp. and E. coli in any of the tested concentrations. Trihydral was the most effective. Comparing the experimental dentifrices, the product with 10% R. communis produced the largest zones of bacterial growth inhibition and had similar antimicrobial activity to the commercial dentifrices, except against S. aureus.

Efficacy of citric acid denture cleanser on the Candida albicans biofilm formed on poly(methyl methacrylate): effects on residual biofilm and recolonization process

BACKGROUND

It is well known that the use of denture cleansers can reduce Candida albicans biofilm accumulation; however, the efficacy of citric acid denture cleansers is uncertain. In addition, the long-term efficacy of this denture cleanser is not well established, and their effect on residual biofilms is unknown. This in vitro study evaluated the efficacy of citric acid denture cleanser treatment on C. albicans biofilm recolonization on poly(methyl methacrylate) (PMMA) surface.

METHODS

C. albicans biofilms were developed for 72 h on PMMA resin specimens (n = 168), which were randomly assigned to 1 of 3 cleansing treatments (CTs) overnight (8 h). CTs included purified water as a control (CTC) and two experimental groups that used either a 1:5 dilution of citric acid denture cleanser (CT5) or a 1:8 dilution of citric acid denture cleanser (CT8). Residual biofilms adhering to the specimens were collected and quantified at two time points: immediately after CTs (ICT) and after cleaning and residual biofilm recolonization (RT). Residual biofilms were analyzed by quantifying the viable cells (CFU/mL), and biofilm architecture was evaluated by confocal laser scanning microscopy (CLSM) and scanning electron microscopy (SEM). Denture cleanser treatments and evaluation periods were considered study factors. Data were analyzed using two-way ANOVA and Tukey's Honestly Significant Difference (HSD) test (α = 0.05).

RESULTS

Immediately after treatments, citric acid denture cleansing solutions (CT5 and CT8) reduced the number of viable cells as compared with the control (p < 0.01). However, after 48 h, both CT groups (CT5 and CT8) showed biofilm recolonization (p < 0.01). Residual biofilm recolonization was also detected by CLSM and SEM analysis, which revealed a higher biomass and average biofilm thickness for the CT8 group (p < 0.01).

CONCLUSION

Citric acid denture cleansers can reduce C. albicans biofilm accumulation and cell viability. However, this CT did not prevent biofilm recolonization.

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

Introduction: The effectiveness of antimicrobial solutions employed in dental prosthesis decontamination is still uncertain. Aim: To evaluate the antifungal activity of cleaners used in the decontamination of dental prostheses on the growth of Candida albicans. Material and method: The evaluated products were: Corega Tabs(r) (S1), Sodium Hypochlorite 1% (S2), Sodium Bicarbonate 1% (S3), Hydrogen Peroxide 1% (S4), Chlorhexidine Digluconate 0.12% - Periogard (r) (S5), Mouthrinse based on essential oils - Listerine(r) (S6), essential oil from Rosmarinus officinalis (rosemary) at concentrations of 1% (S7) and 2% (S8). The antifungal activity of the products was evaluated by agar diffusion technique and the determination of microbial death curve of samples of C. albicans (ATCC 90028) in concentration 1.5 × 106 CFU/mL. The tests were performed in triplicate and statistical analysis was made by ANOVA Two-Way and Tukey tests, with the confidence level of 95%. Result: The average of the zones of inhibition growth, in millimeters, obtained for the products were: 0.0 (S1), 44.7 (S2), 0.0 (S3), 21.6 (S4), 10.0 (S5), 6.1 (S6), 0.0 (S7) and 2.4 (S8). Considering the determination of microbial death curve, all products showed a statistical difference (p<0.01) from control (0.85% sodium chloride) and S3 groups. Fungal growth less than 2×104 CFU/mL and an accentuation of the microbial death curve were observed after 30 minutes, with exception for S3 and control groups. Conclusion: The studied compounds, with the exception of Sodium Bicarbonate, have antifungal effect against C. albicans, which contribute for dental prostheses hygiene.