Green Route to Produce Silver Nanoparticles Using the Bioactive Flavonoid Quercetin as a Reducing Agent and Food Anti-Caking Agents as Stabilizers.

In previous work, the isolated polyphenolic compound (PPC) quercetin was used as a reducing agent in the formation of silver nanoparticles (AgNPs), testing two types of quercetin. This PPC is a bioactive molecule that provides the electrons for the reduction of silver ions to zerovalent silver. The results demonstrated that quercetin in dietary supplement presentation was better than reagent grade quercetin for the synthesis of AgNPs, and the difference between them was that the dietary supplement had microcrystalline cellulose (CM) in its formulation. Therefore, this dietary anti-caking agent was added to the reagent-grade quercetin to validate this previously found improvement. AgNPs were obtained at neutral pH by a green route using quercetin as a reducing agent and microcrystalline cellulose and maltodextrin as stabilizing agents. In addition, different ratios were evaluated to find the optimum ratio. Ultraviolet-Visible spectroscopy (UV-VIS), Atomic Force Microscope (AFM), Z-potential, Dynamic Light Scattering (DLS) and X-ray Powder Diffraction (XRD) were used for characterization. The antibacterial activity of the S. aureus and E. coli agent was tested by the disk diffusion and microdilution method. According to the results, this green synthesis needs the use of food stabilizer when working at pH 7 to maintain AgNPs in the long term. The ideal ratio of reducing the agent:stabilizing agent was 1:2, since with this system stable AgNPs are obtained for 2 months and with improved antimicrobial activity, validating this method was ecologically and economically viable.

Punica granatum as Anticandidal and Anti-HIV Agent: An HIV Oral Cavity Potential Drug.

The oral cavity is crucial from diagnosis to adherence to HAART therapy in the HIV/AIDS population; consequently, drugs that can maintain healthy conditions in the oral cavity are necessary for patients with HIV/AIDS. Punica granatum (pomegranate) is a tree that has been employed extensively for centuries in the traditional medicine of ancient cultures for the treatment of a wide range of diseases, including oral and dental diseases. In recent decades, its potent anticandidal properties have been shown, especially on Candida albicans, the cause of the most common clinical manifestation in HIV patients. The present work contributes to the review of the anti-HIV and anticandidal properties of the plant species P. granatum as involved with the oral cavity. The literature reviewed revealed that crude extracts of pomegranate and its main isolated compounds possess inhibitory activity on different HIV targets, including binding viral proteins and the three replicative HIV enzymes. In addition, in the literature reviewed, pomegranate exhibited anticandidal effects on 10 different species. Thus, pomegranate appears to be an excellent candidate to explore and incorporate into the treatment of the oral cavity of HIV/AIDS patients, in that, in addition to its pharmacological effects such as antiviral and anticandidal, pomegranate represents an easily available, inexpensive, and safe natural source.

Use and management of disinfectants by dentists in San Luis Potosi, Mexico, during the covid-19 pandemic / Uso y manejo de desinfectantes por odontólogos de San Luis Potosí, México durante la pandemia covid-19

Introduction: Chlorine, ethyl alcohol, and quaternary ammonium are disinfectants with antiviral activity against SARS-Cov2. However, there are no previous reports of their use and handling for cleaning and disinfection in dental offices. Objetive: To determine the use and management of disinfectants in critical and non-critical areas used by dentists in San Luis Potosí, Mexico, during the COVID-19 pandemic. Material and Methods: A validated cross-sectional survey was applied online to 100 dentists in San Luis Potosí between February and June 2021. Participants were informed about the handling of personal data according to the standard DOF regulations (DOF 07-05-2010). Results: A total of 100 dentists were included in the study, 63% female and 37% male, with a mean age of 26 years. The most widely used disinfectants during the pandemic in critical areas were Lysol® and 0.1% sodium hypochlorite in non-critical areas. Eighty-five percent of dentists know the adverse effects of inappropriate use of disinfectants, 72% did not have any sign or symptom associated with the use of disinfectants. The most used protection barrier was gloves (97%). Sixty-seven per cent of dentists disposed of disinfectant waste down the drain. Conclusion: Sodium hypochlorite and quaternary ammonium compounds and/or ethanol are used to clean non-critical and critical areas in dental offices. However, appropriate measures for their management are not adopted. It is necessary to implement educational strategies to improve the use and management of disinfectants in dental practice.

Introducción: Cloro, alcohol etílico y amonio cuaternario son desinfectantes que muestran actividad antiviral contra el SARS-Cov2, sin embargo, no existen reportes previos de su uso y manejo para la limpieza y desinfección en clínicas dentales. Objetivo: Determinar el uso y manejo de los desinfectantes en áreas críticas y no críticas empleados por los odontólogos en San Luis Potosí durante la COVID-19. Material y Métodos: Encuesta transversal validada y aplicada on-line a 100 odontólogos de San Luis Potosí durante febrero-junio 2021. Se informó a los participantes sobre el manejo de datos personales de acuerdo a la norma (DOF 05-07-2010). Resultados: Se incluyeron un total de 100 odontólogos, 63% del sexo femenino y 37% del sexo masculino, con una edad promedio de 26 años. Los desinfectantes más utilizados durante la pandemia en las áreas críticas fueron el Lysol® y el hipoclorito de sodio al 0.1% en áreas no críticas. El 85% de los odontólogos conocen los efectos adversos del uso inadecuado de los desinfectantes, 72% no tuvieron algún signo o síntoma asociado al uso de desinfectantes. La barrera de protección más utilizada fueron los guantes (97%). El 67% de los odontólogos eliminó los desechos de desinfectantes por la coladera. Conclusión: Para la limpieza de las áreas no críticas y críticas en las clínicas dentales se utilizan el hipoclorito de Sodio y compuestos de amonio cuaternario y/o etanol, sin embargo, no se utilizan las medidas adecuadas para su manejo. Es necesario implementar estrategias educativas para mejorar el uso y manejo de desinfectantes en la práctica dental.

Anti-HIV and Anti-Candidal Effects of Methanolic Extract from Heteropterys brachiata.

Nowadays, the HIV pandemic is far from controlled. HIV+/AIDS patients show a serious risk of developing resistance to HIV antiretroviral drugs and to be orally colonized by albicans and non-albicans Candida strains resistant to antifungals. As a consequence, new drugs that possess anti-candidal and anti-HIV effects would represent an alternative in the comprehensive treatment of HIV+/AIDS patients. The present study evaluates the possible anti-HIV and anti-Candida effects of a methanolic extract from Heteropterys brachiata (Hb MeOH), an American tropical plant. The anti-HIV effect of Hb MeOH was tested using a non-radioactive colorimetric method (Lenti RT® Activity Assay; Cavidi Tech) that uses reverse transcriptase of HIV-1 enzyme as enzymatic target. The anti-candidal effect of HbMeOH extract was evaluated by following a standardized test protocol of microdilution for yeast using the Candida albicans strain ATCC® 90028. The Hb MeOH at 1 mg/mL concentration shows 38.5% RT-HIV inhibition, while Hb MeOH at 10 mg/mL concentration produced 98% C. albicans growth inhibition. Our findings show that the Hb MeOH possesses a strong anti-candidal activity and moderate anti-HIV effect and suggests that the plant extract could be considered as a potential candidate for HIV/AIDS treatment.

Effect of dental restorative materials surface roughness on the in vitro biofilm formation of Streptococcus mutans biofilm.

PURPOSE: To evaluate Streptococcus mutans biofilm formation over different restorative dental materials. METHODS: Using a bioreactor over 72 hours, four commercially available ceramics were evaluated: IPS E-max Press, IPS E-max CAD, Lava Ultimate CAD-CAM, Vita Enamic and two resin composites (SR Nexco Paste and Brilliant NG). The results were evaluated using atomic force microscopy and confocal microscopy, the biofilm was stained and the arbitrary fluorescence units (AFU) quantified. RESULTS: The results showed that IPS E-max CAD had the lowest roughness values (4.29±1.79 nm), while the highest values were observed for Vita Enamic discs ( (77.13±17.35 nm). Analysis of S. mutans biofilm formation by AFU revealed lower values for IPS E-max CAD (6.77±1.67 nm); the highest values were found for Lava Ultimate (79.99±22.23 nm). Regarding the composite groups, SR Nexco Paste showed roughness values of 15.07±2.77 nm and lower arbitrary fluorescence units of 30.92±12.01 nm than Brilliant NT. There was a correlation between the surface roughness of ceramics and composite with S. mutans biofilm formation. CLINICAL SIGNIFICANCE: The adhesion of oral bacteria to restorative dental materials plays a key role in the success of dental treatment; the surface roughness influences the S. mutans biofilm formation.

Reduction of Candida albicans biofilm formation by coating polymethyl methacrylate denture bases with a photopolymerized film.

STATEMENT OF PROBLEM: As Candida albicans biofilm formation is associated with severe local and systemic infections in denture-wearing patients, its prevention or reduction becomes an essential factor in the health of this population. PURPOSE: The purpose of this in vitro study was to investigate whether 2 photopolymerized coatings of poly(acrylic acid) (PAA) and poly(itaconic acid) (PIA) can effectively reduce the adhesion of C albicans on denture base acrylic resin surfaces. MATERIAL AND METHODS: The surface of the polymethyl methacrylate (PMMA) denture base was modified through photopolymerization of a thin film of PAA or PIA. The polymeric coatings were characterized by scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), X-ray photoelectron spectroscopy (XPS), contact angle goniometry (CA), and surface roughness measurement (Ra). For biological evaluation, the coated PMMA surfaces were tested in a C albicans biofilm dynamic formation model, observed by confocal laser scanning microscopy (CLSM), and quantified by the number of colony-forming units (CFUs). The cytotoxicity of the polymeric coatings was also evaluated by using a lactic dehydrogenase-based (LDH) test. For statistical analysis, ANOVA and the nonparametric Kruskal-Wallis test were used (α=.05). RESULTS: The PMMA resin base surfaces coated with PAA and PIA had an inhibitory effect on C albicans growth, the wettability of the coated surface, and the average roughness. The PAA and PIA coatings had no statistically significant cytotoxic effect on periodontal ligament fibroblasts. CONCLUSIONS: PMMA acrylic resin base material was superficially modified through the incorporation of carboxylic acid groups by using PAA and PIA coatings that reduced the adherence of C albicans biofilm by 90%.

Dual function of EDTA with silver nanoparticles for root canal treatment-A novel modification.

The chelating and antimicrobial capacity of a novel modification of 17% EDTA with silver nanoparticles (AgNPs) (EDTA-AgNPs) was evaluated in-vitro for root canal treatment (RCT). The EDTA-AgNPs solution was characterized by UV-Vis spectroscopy, ζ-potential and high-resolution transmission electron microscopy (HRTEM). Antimicrobial capacity was evaluated against Candida albicans and Staphylococcus aureus in planktonic and biofilm cells by broth macrodilution (24 h) and XTT assays, (1, 10 and 30 min) respectively. The chelating capacity of EDTA-AgNPs was assessed indirectly (smear layer removal) and directly (demineralizing effect) in bovine dentin at two silver concentrations, 16 and 512 µg/ml at 1 and 10 minutes of exposure time. Smear layer removal was evaluated by atomic force microscopy (AFM) and scanning electron microscopy (SEM). The demineralizing effect was determined by atomic absorption spectroscopy (AAS), microhardness test (MH) and X-ray diffractometer (XRD). Synthesized AgNPs were quasi-spherical in shape with an average size of 13.09 ± 8.05 nm. 17% EDTA-AgNPs was effective to inhibit C. albicans and S. aureus in planktonic and biofilm cultures. The smear layer removal and demineralizing effect were similar between 17% EDTA-AgNPs and 17% EDTA treatments. The 17% EDTA-AgNPs solution proved to be an effective antimicrobial agent, and has a similar chelating capacity to 17% EDTA alone. These in-vitro studies strongly suggest that EDTA-AgNPs could be used for effective smear layer removal, having an antimicrobial effect at the same time during RCT.

Colonización e infección bucal por Candida sp. en pacientes diabéticos y no diabéticos con enfermedad renal crónica en diálisis / No disponible

Introducción: La candidosis bucal (CB) es una infección oportunista frecuente en el paciente inmunocomprometido y algunas veces es importante conocer la especie para el tratamiento. Objetivo: Determinar la prevalencia de distintas especies de Candida colonizando o infectando la mucosa bucal (MB) de pacientes diabéticos (DM) y no diabéticos (no DM) con enfermedad renal crónica, comparando ambos grupos y explorando algunos posibles factores de riesgo. Metodología: Se examinó a 56 pacientes DM y 80 no DM con diálisis crónica. Se tomaron muestras de la MB y se sembraron en agar placas dextrosa Sabouraud. La especie se identificó con galerías API®. La CB se confirmó con citología exfoliativa. Las asociaciones se investigaron con χ2, Prueva exacta (PE) de Fisher y regresión logística múltiple. Resultados: La prevalencia de Candida fue del 43,4 %: 53,6 % DM y 36,2 % no DM (p = 0,045). Las especies fueron C. albicans 74,6 %, C. glabrata 22,0 %, C. tropicalis 15,2 %, C. parapsilosis 3,4 %, C. kefyr 3,4 % y C. famata 1,7 % sin diferencia entre grupos. Los DM tuvieron mayor frecuencia de xerostomía (p = 0,002), flujo salival bajo (p = 0,008) y albúmina sérica más baja (p = 0,018). Tuvieron CB 16,9 %, 23,2 % DM frente a 12,5 % no DM (p = 0,101). Se asociaron a presencia de Candida en la MB: uso de prótesis (odds ratio [OR] 25,6, límite de confianza [LC] 95 % 2,5 a 253, p = 0,001), xerostomía (OR 9,6, LC 95 % 2,4 a 38,1, p = 0,001) y bajos valores de albúmina sérica (OR 0,41, LC 95 % 0,22 a 0,98, p = 0,044). Conclusiones: La presencia de Candida sp. en la MB se asoció a prótesis dental, xerostomía y albúmina sérica baja (AU)

Introduction: Oral candidiasis (OC) is a common opportunistic infection in immunocompromised patients. Species identification is sometimes important for treatment. Objective: to determine the prevalence of different Candida species colonising or infecting the oral mucosa (OM) of diabetic (DM) and non-diabetic (non-DM) chronic kidney disease patients, comparing both groups and exploring potential risk factors. Methods: 56 DM and 80 non-DM patients on chronic dialysis were examined. OM swabs were cultured on Sabouraud dextrose agar plates. Candida species were identified with API® galleries. OC was confirmed by exfoliative cytology. Statistical associations were analysed using χ2, Fisher's exact test (ET), and multiple logistic regression. Results: Candida prevalence was 43.4%: 53.6% DM and 36.3% non-DM, (p=.045). The species identified were C.albicans 74.6%, C. glabrata 22.0%, C. tropicalis 15.2%, C. parapsilosis 3.4 %, C. kefyr 3.4% and C. famata 1.7% without difference between groups. DM patients had a higher xerostomia prevalence (p=.002) and lower salivary flow (p=.008) and lower serum albumin (p=.018). 16.9% of patients had OC, 23.2% DM compared with 12.5% non-DM, (p=.101). The following were associated with the presence of Candida in the OM: the use of dental prostheses (odds ratio [OR] 25.6, 95% confidence interval [CI] 2.5 to 253, P=.001), xerostomia (OR 9.6, 95% CI 2.4 to 38.1, P=.001) and low serum albumin values (OR 0.41, 95% CI 0.22 to 0.98, P=.044). Conclusions: The presence of Candida sp. in the OM was associated with dental prostheses, xerostomia and low serum albumin (AU)

Detection of Human Papilloma Virus (HPV) in oral mucosa of women with cervical lesions and their relation to oral sex practices.

BACKGROUND: Previous studies have either investigated the relationship of HPV with oral cancer or the prevalence of HPV on the oral cavity. The purpose of this investigation was to study the prevalence of HPV in oral cavity of women with oral sex practices and cervical lesions. METHODS: Forty six (46) non-smokers and non-alcoholic patients attended the "Clínica de Displasias" of "Ciudad Juarez" were sampled. This population had a CIN diagnosis sometime between the previous six months. On previous consent they filled out a questionnaire related to their oral sex practices. Afterwards one swab from cheeks and another from palate/gum were taken; PCR was used to determine generic HPV, HPV16 and HPV18. RESULTS: Seventy two percent (72%) of the patients stated to have oral sex practices regularly which all of them were positive to HPV either in oral mucus, palate/gum or both. The total of the given results showed that 35% had HPV16; among those distributed in 26% with regular oral sex practices and 9% stated as never practiced oral sex. An association was found between oral HPV16 positivity and progression to cervical CIN advanced lesions. On the other hand HPV18 was not detected. The frequency of HPV16 was higher in buccal mucosa (23%) versus palate/gum (16%). CONCLUSIONS: This study suggests that buccal HPV16 infection is associated with CIN progression.

Description of the subgingival microbiota of periodontally untreated Mexican subjects: chronic periodontitis and periodontal health.

BACKGROUND: Recent studies have suggested that changes in the prevalence and/or proportion of distinct microorganisms characterize the subgingival microbial profiles of populations around the world. At present, no information is available on the subgingival microbiota of Mexican subjects. The purpose of the present study was to determine the microbial composition of subgingival plaque in Mexican subjects with untreated chronic periodontitis. METHODS: A total of 44 chronic periodontitis and 20 periodontally healthy subjects (who were currently non-smokers) were selected. Clinical measurements including plaque accumulation, gingival erythema, bleeding on probing, suppuration, probing depth, and attachment level were recorded at six sites of every tooth. Up to 28 subgingival plaque samples were obtained from each subject and individually analyzed to determine the levels, proportion, and prevalence of 40 microbial species using the checkerboard DNA-DNA hybridization technique. RESULTS: Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythensis were the only species that presented higher mean levels in periodontitis subjects. The proportions of P. gingivalis (P<0.001), T. forsythensis (P<0.01), and red complex species (P. gingivalis, T. forsythensis, and T. denticola; P<0.001) as a group were also significantly higher in periodontitis subjects. Periodontally healthy subjects harbored a significantly larger proportion of Actinomyces species (P<0.05). No significant differences were detected in the percentage of carriers of any of the species tested. CONCLUSIONS: Our results revealed that the subgingival microbiota of untreated chronic periodontitis Mexican subjects was characterized by increases in the level, prevalence, and proportion of classic periodontal pathogens. However, the prevalence and proportion of specific microbial species varied significantly from the results of other reports on subjects from different geographical locations.