Monoterpene antifungal activities: evaluating geraniol, citronellal, and linalool on Candida biofilm, host inflammatory responses, and structure-activity relationships.

Introduction: Despite the rising concern with fungal resistance, a myriad of molecules has yet to be explored. Geraniol, linalool, and citronellal are monoterpenes with the same molecular formula (C10H18O), however, neither the effect of these compounds on inflammatory axis induced by Candida spp. nor the antibiofilm Structure-Activity Relationship (SAR) have been well-investigated. Herein we analyzed geraniol, linalool and citronellal antifungal activity, cytotoxicity, and distinctive antibiofilm SAR, also the influence of geraniol on Candida spp induced dysregulated inflammatory axis, and in vivo toxicity. Methods: Minimal inhibitory (MIC) and fungicidal (MFC) concentrations against Candida spp were defined, followed by antibiofilm activity (CFU-colony forming unit/mL/g of dry weight). Cytotoxic activity was assessed using human monocytes (THP-1) and oral squamous cell (TR146). Geraniol was selected for further analysis based on antifungal, antibiofilm and cytotoxic results. Geraniol was tested using a dual-chamber co-culture model with TR146 cells infected with C. albicans, and THP-1 cells, used to mimic oral epithelium upon fungal infection. Expression of Candida enzymes (phospholipase-PLB and aspartyl proteases-SAP) and host inflammatory cytokines (interleukins: IL-1ß, IL-6, IL-17, IL-18, IL-10, and Tumor necrosis factor-TNF) were analyzed. Lastly, geraniol in vivo toxicity was assessed using Galleria mellonella. Results: MIC values obtained were 1.25-5 mM/mL for geraniol, 25-100 mM/mL for linalool, and 100-200 mM/mL for citronellal. Geraniol 5 and 50 mM/mL reduced yeast viability during biofilm analysis, only 500 mM/mL of linalool was effective against a 72 h biofilm and no biofilm activity was seen for citronellal. LD50 for TR146 and THP-1 were, respectively: geraniol 5.883 and 8.027 mM/mL; linalool 1.432 and 1.709 mM/mL; and citronellal 0.3006 and 0.1825 mM/mL. Geraniol was able to downregulate expression of fungal enzymes and host pro-inflammatory cytokines IL-1ß, IL-6, and IL-18. Finally, safety in vivo parameters were observed up to 20 mM/Kg. Discussion: Despite chemical similarities, geraniol presented better antifungal, antibiofilm activity, and lower cytotoxicity when compared to the other monoterpenes. It also showed low in vivo toxicity and capacity to downregulate the expression of fungal enzymes and host pro-inflammatory cytokines. Thus, it can be highlighted as a viable option for oral candidiasis treatment.

Using Laser Therapy and Topical Ozone as an Effective Intervention to Revolutionize Denture Stomatitis Treatment: A Case Report.

In dentistry, denture stomatitis (DS), a frequent inflammatory illness of the oral mucosa mostly related to denture wearing, is a major concern. DS is a common oral mycotic infection for those who wear partial or total dentures. The most often found species of Candida that may be isolated from both healthy and diseased oral tissues is Candida albicans. DS is associated with uneven denture surfaces, inadequate oral hygiene, or ill-fitting dentures. The diagnosis and management of DS in a 72-year-old male patient is presented in this case study. The patient complained about burning in his palate and having difficulty chewing. Upon clinical examination, erythema and inflammation were seen in the palate region. The history and clinical findings were consistent with DS. The patient was told to completely stop using dentures. Interventions were included in the treatment plan, such as diode laser therapy, topical ozonated oil application, and teaching about denture hygiene. The third day's follow-up visit revealed a progressive healing of the lesions and symptom relief. The lesion fully resolved on the sixth day. This case emphasizes the value of all-encompassing management techniques in treating DS successfully. It also highlights the significance of patient education, good oral hygiene, and focused therapy in producing favorable results.

Antifungal agents incorporated in denture base materials: a scoping review of the current evidence and technology prospecting.

BACKGROUND: The aim of this study was to summarize existing data and perform technological prospecting on the effect of incorporating antifungal agents into denture base materials in inhibiting Candida spp., as well as to explore the antimicrobial properties of these materials. METHODS: A comprehensive electronic search was carried out in six major bibliographic databases (PubMed, Scopus, Embase, Cochrane Library, Web of Science and Lilacs) until February 2024. In addition, international patent databases were also examined. The search process, study and patent selection, data extraction and risk of bias assessment were carried out independently by researchers. The collected data underwent qualitative analysis. RESULTS: A total of 10 718 articles were identified in the searched databases, of which 40 documents were included for qualitative data analysis (articles: 31; patents: 9). The majority of the studies focused on investigating tissue conditioners (n = 14) and acrylic resins (n = 14). The primary antifungal agents studied were nystatin (n = 15) and fluconazole (n = 13). The most commonly utilized microbiological evaluation methodology was the agar diffusion test (n = 16), followed by the microdilution (n = 7) and biofilm formation assays (n = 7). All of the studies investigated the inhibitory effect of these materials against Candida species. CONCLUSION: The incorporation of antifungal agents into denture base materials has been extensively studied and has shown a significant inhibitory response against Candida spp. across various methodological assays.

Antifungal recombinant psoriasin of human origin effectively inhibits fungal growth on denture base.

OBJECTIVE: To evaluate the efficacy of recombinant psoriasin as a novel treatment for oral candidiasis by eliminating Candida albicans growth on polymethyl methacrylate denture base. MATERIALS AND METHODS: Recombinant psoriasin protein was expressed and purified from E. coli, and Candida growth was monitored in vitro with varying concentrations of psoriasin. Subsequently, denture-base polymethyl methacrylate was immersed in psoriasin's solution or voriconazole, and fungal growth on the acrylic base and in the medium was examined by scanning electron microscopy and optical density, respectively. Cellular viability of HeLa and human gingival fibroblast cells treated with psoriasin was measured by methylene blue assay. RESULTS: The findings reveal an effective antifungal activity of psoriasin, completely inhibiting Candida albicans growth in RPMI at a protein concentration above 400 nM. Immersing the polymethyl methacrylate with 50 µM psoriasin completely eradicates fungal growth. Psoriasin has low cytotoxicity in HeLa cells at a concentration higher than 12 µM and no toxic effect on human gingival fibroblasts. CONCLUSIONS: This study marks psoriasin as an effective alternative to conventional antifungal treatments for denture stomatitis and a safe alternative to chemical antifungals in dental medicine and beyond.

Effectiveness of Denture Cleansers on Candida albicans Biofilm on Conventionally Fabricated, Computer-Aided Design/Computer-Aided Manufacturing-Milled, and Rapid-Prototyped Denture Base Resins: An In Vitro Study.

INTRODUCTION: Conventionally fabricated denture base resins have been used for over 150 years. Newer denture base resins can provide a superior fit and may be customized to the patient's characteristics, but the literature on their cleansibility remains limited. The oral cavity can be a hub for thousands of microflora. The maintenance of complete dentures by edentulous patients depends not only on the maintenance of the patient but also on the material used, biofilm adherence, and polishability. MATERIALS AND METHODS: Cuboid specimens of 10 × 5 × 2 mm were designed using the Meshmixer version 3.5 software (Meshmixer, Australia). The standard tessellation (STL) file was imported and sent for printing (NextDent, Netherlands) (Group 1), milling in polymethyl methacrylate (PMMA) (Ivotion, Ivoclar, Schaan, Liechtenstein) (Group 2), and wax milling (Upcera, China), followed by flasking, counter flasking, and packing using heat-cured acrylic resin (DPI, India) (Group 3). The obtained specimens were polished using pumice and sterilized using a UV sterilization unit. The specimens were then immersed in a suspension of candida broth. After three days of biofilm formation, a colony count was performed and noted as colony-forming units per milliliter (CFU/mL). Specimens were treated using Secure denture cleansing tablets (Ghent, New York), table salt (iodized table salt, Tata, India), Clinsodent (ICPA, Mumbai, India), and Polident denture cleansing powder (Polident, Ontario, Canada). A colony count was done after treatment, and the data were tabulated. Statistical analysis was done using SPSS software to compare the efficiency of denture cleansers in all three groups, and statistical significance was set at 0.05. The Kolmogorov-Smirnov test was done to confirm the normality of the data, followed by a one-way analysis of variance (ANOVA) test to compare the efficiency of denture cleansers on the removal of candida colonies. RESULTS: Milled denture base resins showed a significantly lower colony count when compared to printed and conventionally fabricated denture base resins. The denture cleansers showed high efficacy in all groups, with the most significant being Secure, which showed a mean difference ranging from 8.114 to 9.887 CFU/mL, followed by Clinsodent, showing a mean of 6.699-9.863 CFU/mL, followed closely by Polident, showing 4.964-7.114 CFU/mL, followed by table salt, being 5.254-8.920 CFU/mL. The 95% confidence interval confirmed statistical significance. CONCLUSION: The highest candida colony count was demonstrated by the conventional, followed by rapid prototyping, and was least with milled denture base resins. Following treatment with denture cleansers, Secure demonstrated almost complete eradication of colonies, making it the most effective option. Salt exhibited the lowest efficiency, followed closely by Polident and Clinsodent, and the most effective was Secure denture cleanser.

Efficacy of ultrasonic home-care denture cleaning versus conventional denture cleaning: A randomised crossover clinical trial.

OBJECTIVE: To compare the efficacy of test (ultrasonic cleaner combined with immersion in denture cleanser solution) and control (immersion in denture cleanser solution followed by conventional brushing) denture cleaning interventions in enhancing denture cleanliness, reducing denture stomatitis, and improving patient satisfaction. METHODS: A prospective, single-blind, block-randomised, two-period crossover, superiority-controlled clinical trial was conducted of a 3-month intervention. The study design included a pre-intervention period (2 weeks), intervention period one (3 months), washout period (2 weeks), and intervention period two (3 months). A total of 56 community-dwelling elders were block-randomized into either sequence Test/Control or sequence Control/Test. The intervention, period, and carryover effects for the changes in the cleanliness of extensive partial and complete acrylic dentures, denture stomatitis, and changes in patient satisfaction were estimated using Generalized Estimating Equations models. RESULTS: Percentage plaque area coverage, patient satisfaction, and denture stomatitis were significantly improved for both intervention and control arms after 3 months (P < 0.05). The intervention arm was found to significantly improve denture cleanliness (P < 0.001) and patient satisfaction (P = 0.002) more than the control arm. Denture-wearing habits and denture age were also significantly associated with the changes in denture plaque coverage (P < 0.05). However, the effect of the test intervention on denture stomatitis was not significantly different compared to the control arm (P = 0.284). CONCLUSION: This study revealed that the test intervention group was significantly more effective than the control group in improving denture cleanliness and patient satisfaction among community-dwelling elders. This test intervention is recommended for maintaining optimum denture hygiene among older adults. CLINICAL SIGNIFICANCE: Removable dentures can harbor opportunistic pathogens, emphasizing the need for effective denture hygiene intervention using ultrasonic cleaner combined with immersion in denture cleanser solution to eliminate denture biofilm in community-dwelling elders.

Photoactivated disinfection procedure for denture stomatitis in diabetic rats.

Objective: To study the efficacy of PADTM Plus-based photoactivated disinfection (PAD) for treating denture stomatitis (DS) in diabetic rats by establishing a diabetic rat DS model. Methods: The diabetic rat DS model was developed by randomly selecting 2-month-old male Sprague-Dawley rats and dividing them into four groups. The palate and denture surfaces of rats in the PAD groups were incubated with 1 mg/mL toluidine blue O for 1 min each, followed by a 1-min exposure to 750-mW light-emitting diode light. The PAD-1 group received one radiation treatment, and the PAD-2 group received three radiation treatments over 5 days with a 1-day interval. The nystatin (NYS) group received treatment for 5 days with a suspension of NYS of 100,000 IU. The infection group did not receive any treatment. In each group, assessments included an inflammation score of the palate, tests for fungal load, histological evaluation, and immunohistochemical detection of interleukin-17 (IL-17) and tumor necrosis factor (TNF-α) conducted 1 and 7 days following the conclusion of treatment. Results: One day after treatment, the fungal load on the palate and dentures, as well as the mean optical density values of IL-17 and TNF-α, were found to be greater in the infection group than in the other three treatment groups (P < 0.05). On the 7th day after treatment, these values were significantly higher in the infection group than in the PAD-2 and NYS groups (P < 0.05). Importantly, there were no differences between the infection and PAD-1 groups nor between the PAD-2 and NYS groups (P > 0.05). Conclusions: PAD effectively reduced the fungal load and the expressions of IL-17 and TNF-α in the palate and denture of diabetic DS rats. The efficacy of multiple-light treatments was superior to that of single-light treatments and similar to that of NYS.

A Systematic Review of Denture Stomatitis: Predisposing Factors, Clinical Features, Etiology, and Global Candida spp. Distribution.

Denture stomatitis (DS) is a very common disease in wearers of removable complete and partial dentures with a worldwide prevalence in the range of 20-67%. Both industrially developed and impoverished nations are affected by the illness. DS is often associated with ill-fitting dentures or a fungal infection with Candida spp. Candida is normally found in the oral cavity microbiota, but it can be harmful to the health of elderly people with underlying diseases. Therefore, the purpose of the present study is to offer the most recent information about the epidemiology, etiology, and global distribution of Candida species associated with DS through a systematic review. Several databases, including Medline, Web of Science, and Scopus, were used to conduct an extensive search of the literature published in the previous 20 years. The selection of studies was performed by two authors. The extracted data were as follows: author, year of publication, country, sample, frequency of DS, method of diagnosing stomatitis, species of Candida, risk factors, and etiology of the disease. The JBI Critical appraisal tools were used to assess the quality of the studies. Eventually, twenty-eight studies were included in the systematic review. Twenty-one studies investigated DS, while seven studies examined Candida colonization in patients using removable dentures. The results show that the main causes of DS include the type of dentures, continuous wearing of dentures, and the formation of a Candida biofilm, which is facilitated by poor dental hygiene. Additionally, previous studies have pinpointed the significance of the salivary flow, saliva composition, and salivary pH. The findings of the current review indicate that it is crucial to monitor denture wearers for the appearance of DS, especially the patients whose immunity has been impaired due to a systemic condition. Finally, frequent follow-ups should include a clinical examination and microbial swabs of the palatal mucosa and the mucosal surface of the denture.

Effectiveness of a tissue conditioner containing antifungals in a rat model of denture stomatitis.

AIM: This study investigated the effectiveness of a drug-modified tissue conditioner in an animal model of denture stomatitis. METHODS AND RESULTS: Wistar rats wore a Candida albicans-contaminated palatal device for 4 days. Next, nystatin (Nys) or chlorhexidine (Chx) were added to a tissue conditioner in their raw or ß-cyclodextrin-complexed (ßCD) forms at their minimum inhibitory concentrations. As controls, one group was not subjected to any procedure (NC), one group used sterile devices, one group had denture stomatitis but was not treated (DS), and another had the devices relined with the tissue conditioner without the addition of any drug (Soft). After 4 days of treatment, treatment effectiveness was assessed visually, histologically, and through CFU count, and myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) assays. Rats from the Soft, Nys, Nys:ßCD, and Chx groups presented a significant decrease in the microbial load compared with the untreated group. Treatment groups showed lower MPO and NAG activity compared to the non-treated group. CONCLUSIONS: The addition of antifungals to a soft tissue conditioner can be a promising approach for denture stomatitis treatment.

Clinico-Demographic Parameters of Oral Fungal Infections: An Institutional Retrospective Study.

Introduction Most fungal infections are responsive to antifungal therapy. However, failure to diagnose the same can significantly affect the quality of lives of patients. Timely identification of fungal infections and their association with varied demographic and clinical parameters will help in improving the prognosis of the patient. The present study aims to evaluate the prevalence of fungal infections among various age groups and genders and also to evaluate the association of fungal infections with demographic parameters. Methods This study included a sample size of n = 600. The demographic and clinical details were compiled and transferred to IBM SPSS Version 23 software (IBM Corp., Armonk, NY) for statistical analysis. Descriptive and Pearson chi-square tests were used to analyze the association of the type of fungal infection with gender, age, and comorbidities. A p-value of less than 0.05 is considered statistically significant. Results Angular cheilitis (40%, 240), followed by denture stomatitis (37.5%, 225), were the most common type of fungal infection among the sample population, and the elderly age group (51-72 years) was the most affected. Angular cheilitis was the most common infection among both males (21.4%, 128) and females (18.6%, 112), but candidiasis was reported more in females (18%, 108) than males (3%, 18) (p = 0.00). Angular cheilitis (32%, 192) and candidiasis (18%, 108) were more observed in association with anemia; however, denture stomatitis (34%, 204) was significantly higher among diabetics (p = 0.00). Conclusion The identification of associated systemic and demographic factors is as important as the treatment of fungal infection itself. The recognition of fungal infections and the role of parameters like age, gender, and systemic comorbidities in the development of fungal infections will have valuable implications for public health. Future research is required for a clear understanding of the same.

Interrelationship between Candida Colonization, Dentures, and Mucosal Tissue Inflammation in the Pathogenesis of Denture Stomatitis.

Despite being common, the pathogenesis of denture stomatitis (DS) is poorly known; thus, this study was conducted to examine the relationship between candida, dentures, and mucosal tissue inflammation. One hundred and twenty edentulous patients wearing a denture with clinical signs and symptoms of DS and 30 patients without DS as healthy were involved in the study. Patients with DS were divided into three groups according to Newton's classification and fungal colonies, and denture fit was assessed. No significant difference was observed between age, sex, and denture fit between the two groups (P > 0.05). The fungal colonies in patients with DS were significantly more than the controls. The majority of the patients with good denture fit had degree 1 (localized mucosal inflammation), while the majority of the patients with fair denture fit had degree 2 (diffuse inflammation on the denture bearing area) and the majority with poor denture fit had degree 3 (granular type) (P < 0.001). The fungal colonies were negative for the majority of degree 1 patients (57.1%), while they were positive for the majority of patients with degree 2 (61.3%) and degree 3 (63.2%) inflammation (P = 0.003). We concluded that the pathogenesis of DS is elusive. Multiple factors, including lack of hygiene, reduced salivary flow, poor denture care, and fit, provide an easy pathway for Candida strains to colonize dentures.

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.

Gellan-Based Hydrogel as a Drug Delivery System for Caffeic Acid Phenethyl Ester in the Treatment of Oral Candida albicans Infections.

Candida albicans can cause various types of oral infections, mainly associated with denture stomatitis. Conventional therapy has been linked to high recurrence, toxicity, and fungal resistance, necessitating the search for new drugs and delivery systems. In this study, caffeic acid phenethyl ester (CAPE) and gellan gum (GG) were studied as an antifungal agent and carrier system, respectively. First, we observed that different GG formulations (0.6 to 1.0% wt/vol) were able to incorporate and release CAPE, reaching a controlled and prolonged release over 180 min at 1.0% of GG. CAPE-GG formulations exhibited antifungal activity at CAPE concentrations ranging from 128 to >512 µg/mL. Furthermore, CAPE-GG formulations significantly decreased the fungal viability of C. albicans biofilms at short times (12 h), mainly at 1.0% of GG (p < 0.001). C. albicans protease activity was also reduced after 12 h of treatment with CAPE-GG formulations (p < 0.001). Importantly, CAPE was not cytotoxic to human keratinocytes, and CAPE-GG formulations at 1.0% decreased the fungal burden (p = 0.0087) and suppressed inflammation in a rat model of denture stomatitis. Altogether, these results indicate that GG is a promising delivery system for CAPE, showing effective activity against C. albicans and potential to be used in the treatment of denture stomatitis.

Effects of aging on attachment of Candida albicans to conventional heat-polymerized, CAD-CAM milled, and CAD-CAM 3D-printed acrylic resin bases.

PURPOSE: The aim of this study was to assess Candida albicans attachment on conventionally fabricated (polymethylmethacrylate, PMMA), CAD-CAM milled, and 3D-printed acrylic resin bases pre- and post-simulated thermal aging, along with examining material surface changes after aging. MATERIALS AND METHODS: Forty-six samples (10 mm × 10 mm × 2 mm) for each of four material groups (conventional heat-polymerized PMMA, CAD-CAM milled acrylic resin base, CAD-CAM 3D-printed methacrylate resin base, CAD-CAM 3D-printed urethane methacrylate resin base) were subjected to 0, 1, or 2 years of simulated thermal aging. Microscopic images were taken before and after aging, and C. albicans attachment was quantified using cell proliferation assay (XTT). Statistical analysis employed analysis of variance (α = 0.05). RESULTS: Two-way factorial analysis showed no significant differences based on acrylic resin type or thermal aging (p = 0.344 and p = 0.091 respectively). However, C. albicans attachment significantly differed between 0- and 2-year thermally aged groups (p = 0.004), mainly due to elevated initial attachments on CAD-CAM milled acrylic resin base and CAD-CAM 3D-printed urethane methacrylate resin base. CONCLUSIONS: Regardless of the fabrication technique and material combination, no significant differences were found in C. albicans adhesion pre- or post- thermal aging. Milled and 3D-printed bases compared favorably with heat- polymerized PMMA in their affinity for C. albicans attachment and surface characteristics after aging. These findings indicate that the risk of patients developing denture stomatitis might not be linked to the type of acrylic resin or fabrication method used.

Efficacy of photodynamic therapy on candida colonization and clinical symptoms in denture stomatitis: a systematic review and meta-analysis.

BACKGROUND: Photodynamic therapy (PDT) has been recently proposed as a promising alternative therapy for Denture Stomatitis (DS). The present systematic review and meta-analysis investigated the current available evidence regarding the efficacy of PDT in the management of DS. MATERIALS AND METHODS: PubMed, Scopus, Web of Science, Google Scholar, and ProQuest were searched up to June 7, 2023. All relevant clinical trials were included. RevMan software was used for the statistical analyses. RESULTS: Elven randomized clinical trials (460 DS patients) were included. Eight studies assessed the efficacy of PDT vs. topical antifungal therapy, while three studies assessed the adjunctive use of PDT (PDT + antifungal therapy) vs. topical antifungal therapy alone. The results revealed comparable efficacy of PDT and conventional antifungal therapy on candida colonization at 15 days (MD: 0.95, 95% CI: -0.28, 2.19, p = 0.13) and at the end of follow-up (MD: -0.17, 95% CI: -1.33, 0.98, p = 0.77). The pooled two studies revealed relatively better efficacy of adjunctive use of PDT with antifungal therapy on candida colonization compared to antifungal therapy alone at 15 days (MD: -6.67, 95% CI: -15.15, 1.82, p = 0.12), and at the end of follow-up (MD: -7.14, 95% CI: -19.78, 5.50, p = 0.27). Additionally, the results revealed comparable efficacy of PDT and topical antifungal therapy on the clinical outcomes. CONCLUSIONS: PDT might be considered a viable option for DS either as an adjunct or as an alternative to the topical antifungal medications. Further studies with adequate sample sizes and standardized PDT parameters are warranted.

"Antimicrobial properties of tissue conditioner modified with chitosan and green-synthesized silver nanoparticles: a promising approach for preventing denture stomatitis".

BACKGROUND: Chitosan is known to inhibit the growth of many bacteria and fungi. Tissue conditioners are commonly used to prevent bone destruction under dentures. However, over time, these materials can become a suitable substrate for microbial growth. One approach to improving dental materials is the use of nanoparticles. This study examined the antifungal properties of chitosan and green technique-synthesized silver nanoparticles in combination with tissue conditioners. METHODS: Tissue conditioner materials were mixed with chitosan and silver nanoparticles at concentrations of 0.097%, 0.19%, and 0.37%, along with 1.25 ppm Nystatin, and their antimicrobial properties against Candida albicans were investigated. The growth rate was measured after 24 h of incubation at 37 °C. Non-parametric tests, such as the Kruskal-Wallis H test and Mann-Whitney U test with Bonferroni correction, were used for data analysis after verifying that the groups did not have a normal distribution. RESULTS: Compared with the control and Nystatin groups, the Chitosan-silver groups showed a significant decrease in the number of CFUs of Candida albicans. CONCLUSIONS: The combination of chitosan and silver nanoparticles with tissue conditioner materials is a promising alternative for preventing and treating denture stomatitis. These findings suggest that using very small amounts of nanoparticles in dental materials could effectively prevent microbial growth, which could improve the longevity and efficacy of dental prosthetics and materials.

Cryptocarya moschata extract decreases single and mixed biofilms on acrylic resins.

OBJECTIVE: This study proposed to assess the effect of Cryptocarya moschata extract on single and mixed biofilms formed on denture base and reline acrylic resin. MATERIALS AND METHODS: Single and mixed biofilms of Candida albicans and Streptococcus mutans were formed on the samples and treated with C. moschata extract; Nystatin solution at 100,000 IU/mL or Penicillin antibiotic solution at 100,000 IU/mL; or PBS solution. Antimicrobial activity was analyzed by counting colony-forming units, metabolism assay, assessment of protein components of the biofilm matrix, and of cell viability using confocal laser scanning microscopy (CLSM). Data were submitted to ANOVA and Tukey's post-test (α = 0.05). RESULTS: Cryptocarya moschata extract reduced cell viability of C. albicans and S. mutans single and mixed biofilms formed on samples. For all types of biofilms in the C. moschata group, there was a log reduction of the biofilm, proven by the Alamar Blue assay. Analyzing the extracellular matrix protein components, groups treated with the extract exhibited a lower level of fluorescence compared to the PBS groups. Reduction in thickness biofilm and viable cells was perceptible in the C. moschata group when assessing through CLSM. CONCLUSION: Cryptocarya moschata extract reduced the single and mixed biofilms of C. albicans and S. mutans on acrylic resins.

Evaluation of photodynamic therapy efficacy vs. conventional antifungal therapy in patients with poor-fitting dentures suffering from denture stomatitis. A prospective clinical study.

BACKGROUND: The long-term use of antifungal therapy in denture stomatitis (DS) treatment could be accompanied by antifungal-resistant strain onset, leading to compromised therapeutic procedure and disease reappearance. Photodynamic therapy (PDT) has shown the ability to eradicate oral infections and resistance strains. This prospective clinical study aimed to assess the PDT's effectiveness compared to the conventional treatment on clinical and microbiological parameters in patients with DS without denture wear during the treatment and follow-ups. METHODS: Forty-two patients diagnosed with DS were randomly assigned to one-session single PDT application (test group) or conventional antifungal therapy (control group). Clinical and microbiological parameters were assessed and analyzed before and at 3rd, 15th, and 30th day following the treatments. Microbiological samples were analyzed by a Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The data was statistically analyzed. RESULTS: Prior to the treatment, Candida species, including C. albicans (100%), C. glabrata (33%), C. tropicalis (31%), C. krusei (31%) were isolated in all patients. Both treatment procedures demonstrated a statistically significant reduction in C. albicans at all follow-up time intervals (p < 0.05). However, PDT displayed a statistically significant reduction in C. krusei compared to the conventional treatment at all follow-up periods (p < 0.05). Clinical parameters improved considerably in the test group compared to the control group at the 3rd and 15th day of follow-up. CONCLUSION: One-session single PDT application demonstrated significant improvement in both clinical and microbiological outcomes in a short-term period, resulting in complete Candida spp. eradication compared to conventional antifungal therapy.

Development of novel antimicrobial acrylic denture modified with copper nanoparticles.

PURPOSE: This study aimed to synthesize heat-cured poly(methyl methacrylate) (PMMA) acrylic formulated with copper nanoparticles (nCu) for producing dentures with antimicrobial properties and ability to prevent denture stomatitis (DS). METHODS: nCu/PMMA nanocomposites were prepared through in situ formation of nCu into methyl methacrylate (MMA). The fabricated material was characterized using scanning electron microscopy, spectroscopy (energy-dispersive X-ray, attenuated total reflectance-Fourier-transform infrared, and X-ray photoelectron spectroscopy), X-ray diffraction analysis, and mechanical flexural tests (ISO 20795-1:2008). Antimicrobial activity against Candida albicans and oral bacteria was determined. MTS assay (ISO 10993-5:2009) and copper release experiments were conducted to assess cytotoxicity. In the clinical trial, participants wearing nCu/PMMA (n=25) and PMMA (n=25) dentures were compared; specifically, DS incidence and severity and Candida species proliferation were assessed for 12 months. Data were analyzed using analysis of variance with Tukey's post hoc test (α=0.05). RESULTS: nCu/PMMA nanocomposite loaded with 0.045% nCu exhibited the maximum antimicrobial activity against C. albicans and other oral bacteria without producing cytotoxicity in the wearer. nCu/PMMA dentures retained their mechanical and aesthetic properties as well as inhibited the growth of Candida species on both denture surface and patient palate. DS incidence and severity were lower in the nCu/PMMA denture group than in the PMMA denture group. CONCLUSIONS: PMMA acrylic produced with copper nanotechnology is antimicrobial, biocompatible, and aesthetic and can reduce DS incidence. Thus, this material may act as a novel preventive alternative for oral infections associated with denture use.

Atividade antifúngica de nanofibras de policaprolactona/nistatina: estudo in vitro e in vivo / Antifungal activity of polycaprolactone/nystatin nanofibers: in vitro and in vivo study

Este estudo avaliou a eficácia in vitro e in vivo de mantas de nanofibras (NF) de policaprolactona (PCL) incorporadas com nistatina (NIS) no tratamento da estomatite protética (EP) em modelos animais. NF foram sintetizadas com diferentes concentrações de NIS, totalizando quatro soluções: PCL puro, PCL/NIS 0,045 g, PCL/NIS 0,090 g e PCL/NIS 0,225 g. A liberação da NIS foi analisada por espectroscopia Ultravioleta-Visível. A capacidade das mantas de inibirem o biofilme de Candida albicans, principal fator etiológico da EP, dividindo-se cinco grupos (N=5) compostos por um grupo com controle de células de C. albicans e com PCL puro, além das três concentrações de NIS. A seguir, foi analisada a viabilidade celular em queratinócitos humanos (HaCat) por meio do teste colorimétrico de resazurina. Cinco grupos foram divididos (N=10): controle celular, PCL puro e as três concentrações de NIS. Em modelos animais de ratos Wistar albinos (N=18), dispositivos palatinos (DP) de resina acrílica foram confeccionados simulando próteses totais e utilizados para a indução da EP. Para isso, DP contaminados com C. albicans foram cimentados na região molar da cavidade bucal dos animais e permaneceram em boca por 48 h. Após esse período, os DP foram removidos e os animais foram divididos em três grupos: (C) controle; (B1) com tratamento por mantas de PCL/NIS 0,045 g e (B2) PCL/NIS 0,225 g, com N=6. Então novos DP, livres de contaminação, foram cimentados na cavidade oral dos animais e permaneceu por mais 48 h. Após esse período, os animais foram eutanasiados, a contagem de UFC/ mL foi realizada e os palatos foram coletados para a análise histológica. A curva padrão de NIS obtida apresentou R2 de 0,99. As três concentrações de NF apresentaram liberação de NIS, com pico no tempo de 6 h e valores de 66,26 µg/ mL para PCL/NIS 0,045 g, de 333,87 µg/ mL para PCL/NIS 0,090 g e 436,51 µg/ mL para PCL/NIS 0,225 g, constantes até o fim do experimento. Os grupos com NIS reduziram em 2,5 log10 de crescimento do biofilme fúngico em relação aos grupos sem tratamento, Controle e PCL, sem diferença estatística significativa. Não foi observada citotoxicidade nas células HaCat, com viabilidade celular de 93,7% para PCL/NIS 0,045 g, 72,6% para PCL/NIS 0,090 g e 72,4% para PCL/NIS 0,225 g. A indução da EP nos três grupos foi possível e, porém, sem redução significativa na contagem de UFC/ mL de C. albicans nos grupos B1 e B2. Na análise histológica do grupo C pôde-se observar infiltração de hifas de Candida na camada queratinizada, presença de células inflamatórias formando micro abscessos e um discreto infiltrado inflamatório no tecido conjuntivo subjacente ao epitélio infectado. Nos grupos B1 e B2 não foram encontradas alterações epiteliais, concluindo-se que as NF demonstraram atividade antifúngica in vitro e foram efetivas na prevenção da penetração de hifas no tecido palatino de animais com DP (AU)

This study evaluated the in vitro and in vivo efficacy of nanofiber (NF) mats of polycaprolactone (PCL) incorporated with nystatin (NIS) in the treatment of denture stomatitis (DS) in animal models. NFs were synthesized with different concentrations of NIS, totaling four solutions: pure PCL, PCL/NIS 0.045 g, PCL/NIS 0.090 g, and PCL/NIS 0.225 g. The release of NIS was analyzed by Ultraviolet-Visible spectroscopy. The ability of the mats to inhibit Candida albicans biofilm, the main etiological factor of DS, was assessed by dividing five groups (N=5) composed of a group with C. albicans cell control and with pure PCL, in addition to the three concentrations of NIS. Next, cell viability in human keratinocytes (HaCat) was analyzed using the resazurin colorimetric test. Five groups were divided (N=10): cell control, pure PCL, and the three concentrations of NIS. In albino Wistar rat animal models (N=18), palatal devices (PD) made of acrylic resin were fabricated to simulate total prostheses and used to induce DS. For this, PD contaminated with C. albicans were cemented in the molar region of the animals' oral cavity and remained in the mouth for 48 hours. After this period, the PDs were removed, and the animals were divided into three groups: (C) control; (B1) treated with PCL/NIS 0.045 g mats, and (B2) PCL/NIS 0.225 g, with N=6. Then new, uncontaminated PDs were cemented in the animals' oral cavity and remained for another 48 hours. After this period, the animals were euthanized, UFC/ mL counts were performed, and the palates were collected for histological analysis. The standard NIS curve obtained showed an R2 of 0.99. The three concentrations of NF showed NIS release, with a peak at 6 h and values of 66.26 µg/ mL for PCL/NIS 0.045 g, 333.87 µg/ mL for PCL/NIS 0.090 g, and 436.51 µg/ mL for PCL/NIS 0.225 g, remaining constant until the end of the experiment. The groups with NIS reduced fungal biofilm growth by 2.5 log10 compared to the untreated groups, Control and PCL, with no significant statistical difference. No cytotoxicity was observed in HaCat cells, with cell viability of 93.7% for PCL/NIS 0.045 g, 72.6% for PCL/NIS 0.090 g, and 72.4% for PCL/NIS 0.225 g. Induction of DS in the three groups was possible; however, there was no significant reduction in UFC/ mL counts of C. albicans in groups B1 and B2. Histological analysis of group C revealed infiltration of Candida hyphae in the keratinized layer, presence of inflammatory cells forming micro abscesses, and a discreet inflammatory infiltrate in the connective tissue underlying the infected epithelium. No epithelial alterations were found in groups B1 and B2, concluding that NFs demonstrated in vitro antifungal activity and were effective in preventing hyphal penetration into palatal tissue in animals with PD.(AU)