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.

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.

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.

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.

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.

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)

Effects of disinfection with a vinegar-hydrogen peroxide mixture on the surface characteristics of denture acrylic resins.

OBJECTIVE: This study aimed to investigate changes in the surface characteristics of two denture resins when disinfected with a vinegar-hydrogen peroxide (VHP) mixture. MATERIALS AND METHODS: Microwave-polymerized or 3D printed acrylic resin disks were immersed for 900 min (simulating 90 daily uses) in the following solutions (N = 10): water; 0.5% sodium hypochlorite; hydrogen peroxide and water dilution (1:1 ratio); vinegar and water dilution (1:1 ratio); and VHP mixture. Surface roughness, Knoop microhardness, surface free energy, and scanning electron microscopic images were assessed before and after the immersions. Results were compared using the 2-way ANOVA for repeated measures and Tukey test, at 5% significance. RESULTS: Surface roughness and microhardness did not differ (P > .05) among the solutions and times. Surface free energy and its dispersive component increased (P < .05) for all solutions. All solutions, except for water and VHP mixture, degraded microtopography. CONCLUSIONS: The VHP mixture was not deleterious to conventional and 3D-printed resin surfaces. CLINICAL RELEVANCE: Conventional and 3D printed resin dentures can be disinfected with a VHP mixture in a 1:1 ratio because this mixture does not substantially affect the surface characteristics after 90 daily immersions. On the contrary, sodium hypochlorite, hydrogen peroxide, and vinegar solutions, even in low concentrations, should be used with caution for denture disinfection because they may alter the resin microtopography over time.

Characterization and antifungal activity of chlorhexidine:ß-cyclodextrin inclusion complexes.

Aim: This study aimed to develop, characterize and analyze the antifungal activity of chlorhexidine:ß-cyclodextrin inclusion complexes (Chx:ßCD). Materials & methods: Chx:ßCD were characterized by physicochemical techniques and the susceptibility of nine Candida strains was assessed. The inhibition of Candida albicans biofilm growth was evaluated in a denture material modified with the incorporation of Chx:ßCD. Results: Chx was better complexed in 1:2 molar ratio by freeze-drying. Chx:ßCD presented antifungal activity against all Candida strains. When incorporated into the denture material, Chx:ßCD showed better antifungal activity, as it required about 7.5% of Chx concentration compared with the raw Chx for 14 days. Conclusion: The improved characteristics of Chx:ßCD can result in new formulations to treat oral candidiasis and denture stomatitis.

Many people who wear dentures can get a fungal infection called denture stomatitis. Treating this infection is hard because it often comes back. There are many reasons why it can come back, like not following instructions, taking the wrong amount of medicine or having a bad reaction to the drugs. Using old and poorly fitting dentures and the difficulty to maintain the medicine in the right place can also make it harder to get better. One idea to make treatment easier is to add stronger drugs with fewer side effects to the material used to make dentures. That way, patients would only need to wear dentures with the right amount of medicine for a certain time to treat the infection.

Losartan Plays a Fungistatic and Fungicidal Activity Against Candida albicans Biofilms: Drug Repurposing for Localized Candidosis.

Candidosis is one of the most frequent opportunistic infections and exhibits variable clinical presentations, including oral localized forms. Drugs affecting the renin-angiotensin system targets inhibit secreted aspartic proteases from Candida albicans. The objective of the study was to evaluate whether losartan has antimicrobial action against C. albicans biofilms. Biofilms were treated with losartan or aliskiren (for comparison) for 24 h. Metabolic activity of viable cells and growth inhibition of C. albicans biofilms were assessed using XTT [2,3-Bis(2-Methoxy-4-Nitro-5-Sulfophenyl)-5-[(Phenyl-Amino)Carbonyl]-2H-Tetrazolium Hydroxide] and colony-forming unit assays, respectively. In addition, the cytotoxicity of the drugs on human cells was evaluated using the AlamarBlue assay. Both drugs decreased fungal viability at all concentrations. In addition, all concentrations of losartan inhibited the growth of C. albicans biofilm, ranging from 47% to 88.5%, whereas aliskiren showed inhibition from 1 to 10 mg/mL, which ranged from 16% to 97.6%. Furthermore, at certain concentrations, these drugs maintained the viability of human cells. Losartan and aliskiren have fungistatic and fungicidal action against C. albicans biofilms and are compatible with human cells. Therefore, these antihypertensive drugs can be repurposed to interfere with the metabolism and development of Candida biofilms, which are widely associated with clinical forms of candidosis, including oral localized forms such as denture stomatitis.

Medium-chain fatty acids as an alternative treatment for denture stomatitis in older people.

OBJECTIVE: To determine the effect of medium-chain fatty acids (MCFA) on the severity of denture stomatitis (DS) and the counts of Candida spp. in older people (OP) wearing removable prostheses (RP). MATERIALS AND METHODS: This randomized, controlled and triple-blind study included forty-three OP presenting DS. The control group was treated with 0.12% chlorhexidine (CHX) and the experimental group with MCFA, 2 × /day for 15 days. Intraoral examination and counts of Candida spp. were performed at 0, 7, and 15 days. The differences between both groups in the decrease of the severity of DS and the viability of Candida spp. were determined clinically and microbiologically, respectively. RESULTS: OP carriers of RP treated with MCFA presented remission of the clinical signs of DS, but the Candida spp. counts only decreased significantly in the CHX-treated group at 7 days of treatment (p < 0.05). Besides, MCFA was shown to reduce the clinical signs of DS after the first week of application, while CHX after the second week. CONCLUSIONS: The MCFA is effective in reducing the clinical signs of DS associated with oral candidiasis in subjects with RP. Both treatments showed a significant decrease in severity, for MCFA after the first week and for CHX two weeks after starting the corresponding treatment. CLINICAL RELEVANCE: The MCFA is an effective, harmless, and accessible treatment alternative against DS, since it manages to reduce the severity of the lesion in the milder cases of DS in the oral mucosa of OP carriers of RP.

Candida-associated denture stomatitis: clinical, epidemiological, and microbiological features.

OBJECTIVE: The identification of Candida spp. in denture stomatitis, the clinical manifestations, and the antifungal susceptibility profile lead to a correct and individualized therapeutic management of the patients. This study is aimed at investigating the clinical manifestations and epidemiological and microbiological characteristics of Candida-associated denture stomatitis. DESIGN: The samples were obtained by swabbing the oral mucosa of the subjects and then seeded onto Sabouraud Dextrose Agar and onto CHROMagar® Candida plates. The identification at the species level was confirmed by Matrix Assisted Laser Desorption Time of Flight Mass Spectrometry. Clinical classification was performed according to the criteria proposed by Newton (1962): (i) pinpoint hyperemia, (ii) diffuse hyperemia, and (iii) granular hyperemia. For carrying out the antifungal susceptibility testing, we adopted the CLSI M27-S4 protocol. RESULTS: C. albicans was the most prevalent species in our study. Regarding non-albicans Candida species, C. glabrata was the most common species isolated from the oral mucosa (n = 4, 14.8%), while in the prosthesis, it was C. tropicalis (n = 4, 14.8%). The most prevalent clinical manifestation was pinpoint hyperemia and diffuse hyperemia. Candida albicans, C. glabrata, and C. parapsilosis were susceptible to all the tested antifungals. Concerning fluconazole and micafungin, only two strains showed dose-dependent sensitivity (minimum inhibitory concentration (MIC), 1 µg/mL) and intermediate sensitivity (MIC, 0.25 µg/mL). One C. tropicalis strain was resistant to voriconazole (MIC, 8 µg/mL). CONCLUSIONS: C. albicans was the most common species found in oral mucosa and prosthesis. The tested antifungal drugs showed great activity against most isolates. The most prevalent clinical manifestations were Newton's type I and type II.

Characterization, Antifungal Evaluation against Candida spp. Strains and Application of Nystatin: ß-cyclodextrin Inclusion Complexes.

BACKGROUND: Nystatin (Nys) is a fungicidal drug commonly prescribed for candidiasis disease in several administration routes. However, Nys is a class IV drug, according to the Biopharmaceutical Classification System, that possesses limited bioavailability and is used for local activity. OBJECTIVE: This study developed and characterized nystatin:ß-cyclodextrin (Nys:ßCD) inclusion complexes and evaluated their activity against Candida spp. METHODS: Complexes were characterized by physicochemical techniques and drug dissolution profiles. The susceptibility of C. albicans, C. krusei, C. parapsilosis, C. glabrata, C. guilliermondii, C. tropicalis, and C. auris was assessed using the broth microdilution method. The applicability of Nys:ßCD inclusion complex was evaluated by incorporating it into a temporary soft material for denture stomatitis treatment. RESULTS: Nys was better complexed in a 1:1 molar ratio by freeze-drying and spray-drying methods. The inclusion complexes show bi-exponential release, an initial burst release followed by a sustained manner, presenting higher dissolution efficiency than raw Nys. The 1:1 freeze-drying Nys:ßCD complex presents antifungal activity against all evaluated Candida strains, showing the maintenance of the drug effectiveness. The inclusion complex incorporated into a tissue conditioner material for denture stomatitis treatment effectively inhibited more than 90% of C. albicans biofilm growth during 7 and 14 days, in a half dose compared to raw Nys. CONCLUSION: This work represents a significant contribution to treating a wide variety of diseases caused by the Candida species, optimizing the drug bioavailability and compliance to the treatment due to improved drug solubility, dissolution, and sustained delivery.

Relation between the risk factors for the severity of denture stomatitis and quality of life of complete edentulous individuals: a cross-sectional study

Abstract Objective To assess the association between risk factors for developing denture stomatitis (DS) and oral health-related quality of life (OHRQoL) in complete denture wearers. Methodology Participants of both sexes, wearing complete dentures, were classified using the modified Newton classification for the absence or the severity of DS and allocated to groups Normal or zero, IA, IB, II, and III. Lifestyle, oral and denture history, and medication use were assessed using specific questionnaires; clinical parameters such as anatomical characteristics of support were evaluated with the Kapur classification; salivary flow (SF) was calculated by the volume of unstimulated saliva per minute; and microbial load was determined by counting colony forming units (CFU) of target microorganisms present in the biofilm collected from dentures and palate. OHIP-EDENT assessed the OHRQoL. Kendall's tau_b and Spearman tests were applied with a significance level of 5%. Results 184 patients (143 female and 41 male) aged 65.5 ± 6.8 years were evaluated. Positive correlations were found for sex (women; p=0.013, r=0.16), individuals who started to consume alcoholic beverages as a young adult (18-27 years) (p=0.008, r=0.22), CFU of Candida spp. (p<0.001, r=0.27 denture; p<0.001, r=0.31 palate); Candida albicans (p=0.004, r=0.22 denture; p=0.003, r=0.25 palate), and Candida glabrata (p=0.004, r=0.22 denture; p=0.001, r=0.27 palate). Moreover, negative correlations with DS were found for CFU of Staphylococcus spp. (p=0.004, r=-0.20 palate) and enterobacteria (p=0.002, r=-0.24 palate), as well as a negative correlation between SF (p=0.009, r=-0.193) and DS. The CFU of Staphylococcus spp. and enterobacteria on the palate significantly correlated with OHRQoL. Conclusion Being female, consuming alcoholic beverages as a young adult, CFU of Candida spp., Candida albicans, Candida glabrata, and salivary flow may be the most significant risk factors for DS. The microbial load of Staphylococcus spp. and enterobacteria seems to influence the quality of life for complete denture wearers.

A novel rat model of denture stomatitis and the role of antibiotics in the development of the disease.

This study compared different conditions to establish a rat model of denture stomatitis. Immunocompetent Wistar rats were divided into two groups (n = 35): Tetracycline = administration of 0.83 mg/ml of tetracycline hydrochloride 7 days before induction of denture stomatitis and amoxicillin = administration of 0.156 mg/ml of amoxicillin with clavulanic acid 4 days before induction of denture stomatitis. A suspension of Candida albicans was inoculated on the palate followed by the use of a palatal device contaminated with C. albicans inoculum for 4 days to induce denture stomatitis. As controls, some rats were not submitted to any procedure or used a sterile palatal device for 4 days. The development of denture stomatitis was confirmed by visual analysis, colony-forming units per milliliter (CFU/ml) count, histopathological and immunohistochemical analyses, and through myeloperoxidase (MPO) and N-acetylglucosaminidase (NAG) assays. Rats were euthanized right after device removal (T0), 4 (T4), or 6 (T6) days after device removal. Tetracycline improved the development of the disease, with more severe clinical signs at T0. Similar results were observed in the CFU/ml count and in the histometric and immunohistochemical analyses. Higher MPO expression was detected in the palates of the tetracycline group (P = .006). Despite the subtle differences between antibiotics, tetracycline showed better results in inducing and maintaining denture stomatitis for at least 4 days after device removal.

Denture stomatitis is an oral inflammatory disease with high recurrence rates. Different animal models have been reported in the literature, but some gaps still need to be addressed. A reproducible in vivo model should be established to test new treatment approaches.

Resilient liner modified by antimicrobials for denture stomatitis treatment: A randomized controlled trial.

OBJECTIVES: This randomized clinical trial evaluated the effectiveness of an interim denture resilient liner (Trusoft) modified with minimum inhibitory concentrations (MICs) of antimicrobial agents for Candida albicans biofilm in the denture stomatitis (DS) treatment. METHODS: Forty participants with DS and maxillary complete denture (MCD) wearers were randomly assigned to one of the treatments for 14 days (n=10): nystatin oral suspension (Control-100,000IU/mL; 4 × /day), MCD relined with Trusoft either without (Tru) or with nystatin (Ny) or chlorhexidine diacetate (Chx) at MICs. Cytological smears and mycological quantitative cultures were taken from the palate and denture before treatment (baseline), at the end of treatment (day 14), and at follow-up (days 30, 45, and 60). Photographs of the palate were made at each visit. Data were analyzed by the Cochran and χ2 tests, ANOVA and the Tukey test or the Friedman and Kruskal-Wallis tests (α=0.05). RESULTS: Palatal smears of the Ny and Chx groups exhibited no mycelial Candida (0%) on day 14, and, at the 60-day follow-up, it was observed for only 1 participant from Chx group. MCD smears showed reduction in mycelial forms for all groups on day 14 (P<0.05), but this difference was maintained at follow-up only for the relined dentures (P<0.05). Unlike Tru and the control groups, Ny and Chx groups evidenced a significant reduction in CFU/mL values and DS severity throughout the trial (P<0.05). CONCLUSIONS: The addition of nystatin and chlorhexidine at MICs to an interim resilient liner is a promising treatment for DS, with better results than those for conventional therapy with nystatin suspension, including the follow-ups. CLINICAL SIGNIFICANCE: Compared with conventional topical antifungal therapy, modifying a denture reline material with antimicrobials provided a therapeutic option for denture stomatitis. This non-invasive, straightforward therapeutic approach can be easily adopted by dentists and has the advantage of not requiring patient compliance while maintaining therapeutic concentrations on the denture base.

A modified Newton classification for denture stomatitis.

The effectiveness of denture stomatitis (DS) treatment should be evaluated by associating clinical and mycological parameters. Although widely used in clinical studies, the Newton classification does not accurately represent the degree of severity of palatal inflammation in terms of extent of the lesions and intensity of the erythema. Therefore, a modified Newton classification has been proposed considering the coverage area of palatal inflammation and the erythema level. This consistent and direct ranking will help standardise randomised clinical trials, as well as the statistical comparison among blind evaluations of the obtained scores within and between studies.

Longitudinal Evaluation of Ethyl Cyanoacrylate Adhesives on Candida albicans Biofilm

ABSTRACT: The aim of this study is to evaluate the effect of two ethyl cyanoacrylate-based adhesives on the growth of Candida albicans biofilms on a heat-polymerized resin, after 7, 14, and 30 days of exposure. Ninety circular (10 x 2 mm) heat-polymerized resin specimens were equally divided into three groups: control, conventional ethyl cyanoacrylate (ECAc), and ethyl cyanoacrylate gel (ECAg). Two layers of 50 µL of each material were applied to the respective groups. C. albicans SC5314 strain was activated and standardized to 107 cells/mL-1. Specimens were immersed in 1 mL of artificial saliva and deposited in 1 mL fungal suspension, washed, and immersed in 1 mL of RPMI for 7, 14, and 30 days. The medium was changed at 48-hour intervals. The final suspension was diluted (10 -1 to 10-4) and deposited on Sabouraud dextrose agar for 48 h at 37 °C. After this period, the colonies were quantified using the CFU/mL calculation. Data were evaluated using one- way ANOVA and Tukey's test for post-hoc analysis (P=0.05). It was observed that both adhesives significantly reduced (P<0.05) biofilm formation compared to the control at all evaluated periods. In conclusion, an immediate and long-term inhibitory effect on C. albicans biofilm formation was observed.

RESUMEN: El objetivo del estudio fue evaluar el desarrollo microbiano en superficies de resina acrílica de termopolimerización, acondicionadas previamente, con adhesivos a base de etil cianoacrilato después de 7, 14 y 30 días de exposición en biofilm de Candida albicans. Noventa muestras circulares (10 x 2 mm) de resina acrílica de termopolimerización se dividieron por igual en tres grupos: control, etil cianoacrilato convencional (ECAc) y etil cianoacrilato en gel (ECAg). Se aplicaron dos capas de 50 µl de cada adhesivo en cada muestra. Simultáneamente, se activó la cepa C. albicans SC5314 y se estandarizó a 107 células/ml-1. Las muestras fueron sumergidas en 1 mL de saliva artificial por dos horas y luego se depositó 1 mL de suspensión fúngica por una hora. En seguida cada muestra se lavó y se sumergió en 1 mL de RPMI durante 7, 14 y 30 días, con cambios del medio a cada 48 horas. La suspensión final se diluyó (10-1 a 10-4) y se depositó en agar dextrose Sabouraud durante 48 h a 37° C. Después de este período, las colonias se cuantificaron mediante el cálculo de UFC / mL. Los datos obtenidos se evaluaron por medio del test ANOVA-one way y la prueba de Tukey para el análisis post- hoc (p = 0,05). Se observó que ambos adhesivos redujeron significativamente (P<0,05) la formación del biofilm de Candida albicans al ser comparados con el grupo control en todos los períodos evaluados. Los adhesivos a base de etil cianoacrilato poseen un efecto inhibidor de biofilm de Candida albicans de hasta 30 días, al ser aplicados dos veces en resinas acrílicas de termopolimerización.

Effect of denture liners surface modification with Equisetum giganteum and Punica granatum on Candida albicans biofilm inhibition.

Aim: This study investigated the effect of denture liners surface modification with Equisetum giganteum (EG) and Punica granatum (PG) on Candida albicans biofilm inhibition supposing its usage as a sustained-release therapeutical delivery system for Candida-associated denture stomatitis. Materials & methods:C. albicans biofilm (SC5314 or ATCC 90028) was formed on soft liners superficially modified by a primer mixed to drugs at minimum inhibitory concentrations (0.100 g for EG and PG or 0.016 g for nystatin per ml of primer). After 24 h, 7 or 14 days, antibiofilm activity was evaluated by colony-forming unit counts. Results: Not all groups were equi-efficient to nystatin after 24 h and 7 days. After 14 days, EG and PG efficacies were not different from nystatin (almost 100% inhibition). Conclusion: The proposed protocol presents a promising option to allopathic drugs for Candida-associated denture stomatitis treatment.

Effect of Denture Hygiene Protocols on Patient Satisfaction, Oral Health-Related Quality of Life, and Salivary Parameters: A Randomized Clinical Trial.

PURPOSE: This randomized controlled trial compared four denture hygiene protocols in terms of patient satisfaction, oral health-related quality of life (OHRQoL), and salivary parameters in complete denture wearers with denture stomatitis. MATERIAL AND METHODS: For this randomized, double-blind, controlled clinical trial, 108 participants were assigned to soak their dentures in one of the following solutions: (1) 0.25% sodium hypochlorite (positive control), (2) 0.15% Triclosan, (3) denture disinfecting tablets, or (4) denture disinfecting tablets plus palatine mucosa brushing solution. The outcomes of patient satisfaction, OHRQoL, and salivary parameters (salivary flow rate and pH) were measured at baseline and after 10 days. The Kruskal-Wallis and Dunn tests (between groups), and Wilcoxon test (between times) were used to compare the results. (α = 0.05). RESULTS: After the hygiene protocols, and when compared with baseline, the overall patient satisfaction, maxillary denture satisfaction, maxillary denture comfort, and maxillary denture retention were ameliorated. A significant improvement was noted in OHRQoL in 3 of 4 domains evaluated (orofacial pain and discomfort, masticatory discomfort and disability, and psychological disability and discomfort). The salivary flow rate (unstimulated and stimulated) and salivary pH were not significantly affected at the times evaluated. CONCLUSIONS: Complete denture wearers may feel more satisfied with their complete dentures when treated for denture stomatitis. The tested treatments lead to similar improvement in terms of patient satisfaction and OHRQoL.