Red/Orange Autofluorescence in Selected Candida Strains Exposed to 405 nm Laser Light.

BACKGROUND: Candida albicans and similar species are significant pathogens in immunocompromised and hospitalized individuals, known for mucosal colonization and bloodstream/organ invasion. Many pathogenic fungi, including these species, exhibit autofluorescence (R/OF) under specific light conditions, a feature crucial for their detection. AIM: We investigated the use of a 405 nm diode laser for the direct observation of red/orange autofluorescence of Candida spp., common in the oral cavity, exploring its potential in health screenings. METHODS: This study utilized cultures of Candida spp. on Sabouraud dextrose agar with Qdot 655 and 685 for fluorescence benchmarking, illuminated using a 405 nm diode laser (continuous wave, power 250 mW, 0.0425 J/cm² fluence, 0.0014 W/cm² power density). Images were captured using a yellow-filter camera at set intervals (48 to 144 h). Visual and computational analyses evaluated the R/OF in terms of presence, intensity, coloration, and intra-colony variation. RESULTS: Most Candida strains displayed red/orange autofluorescence at all observation times, characterized by varied coloration and intra-colony distribution. Initially, there was an increase in R/OF intensity, which then stabilized in the later stages of observation. CONCLUSIONS: The majority of the Candida strains tested are capable of emitting R/OF under 405 nm laser light. This finding opens up new possibilities for integrating R/OF detection into routine dental screenings for Candida spp.

Propolis as a Cariostatic Agent in Lozenges and Impact of Storage Conditions on the Stability of Propolis.

Propolis is known as a source of compounds with strong antibacterial activity. Due to the antibacterial effect against streptococci of the oral cavity, it seems to be a useful agent in decreasing the accumulation of dental plaque. It is rich in polyphenols which are responsible for a beneficial impact on the oral microbiota and antibacterial effect. The aim of the study was to evaluate the antibacterial effect of Polish propolis against cariogenic bacteria. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined on cariogenic streptococci related to the occurrence of dental caries. Lozenges based on xylitol, glycerin, gelatin, water, and ethanol extract of propolis (EEP) were prepared. The effect of prepared lozenges on cariogenic bacteria was assessed. Propolis was compared to chlorhexidine which is used in dentistry as the gold standard. In addition, the prepared propolis formulation was stored under stress conditions to assess the influence of physical conditions (i.e., temperature, relative humidity, and UV radiation). In the experiment, thermal analyses were also performed to evaluate the compatibility of propolis with the substrate used to create the base of lozenges. The observed antibacterial effect of propolis and prepared lozenges with EEP may suggest directing subsequent research on prophylactic and therapeutic properties decreasing the accumulation of dental plaque. Therefore, it is worth highlighting that propolis may play an important role in the management of dental health and bring advantages in preventing periodontal diseases and caries as well as dental plaque. The colorimetric analyses carried out in the CIE L*a*b* system, microscopic examinations, and TGA/DTG/c-DTA measurements indicate the unfavorable effect of the tested storage conditions on the lozenges with propolis. This fact is particularly evident for lozenges stored under stress conditions, i.e., 40 °C/75% RH/14 days, and lozenges exposed to UVA radiation for 60 min. In addition, the obtained thermograms of the tested samples indicate the thermal compatibility of the ingredients used to create the formulation of lozenges.

Evaluation of the Sensitivity of Selected Candida Strains to Ozonated Water-An In Vitro Study.

(1) Background and Objectives: Oral candidiasis has increased significantly in recent years. Increasingly, we encounter treatment difficulties related to drug resistance. Therefore, it is necessary to search for other therapies such as ozone therapy, which has antimicrobial activity. The aim of this study was to determine the sensitivity of selected Candida strains to ozonated water based on concentration and contact time (2) Methods: The sensitivity of Candida strains to ozonated water with a concentration of 5 µg/mL, 30 µg/mL, and 50 µg/mL was assessed using Mosmann's Tetrazolium Toxicity (MTT) assay. Statistical differences were assessed by the analysis of variance (ANOVA) and the Newman-Keuls post-hoc test. A p-value of ≤0.05 was considered to indicate a statistically significant difference. (3) Results: In all the strains and research trials, the number of viable cells was reduced by ozonated water. The reduction depended on the exposure time and concentration of ozonated water. The highest percentage reduction (34.98%) for the tested samples was obtained for the C. albicans strain after 120 s of exposure at the highest concentration-50 µg/mL. (4) Conclusions: The selected strains of Candida spp. were sensitive to ozonated water at all tested concentrations (5 µg/mL, 30 µg/mL, and 50 µg/mL). The sensitivity of strains to ozonated water increased with concentration and application time. Moreover, the sensitivity of Candida strains to ozonated water is comparable to that of 0.2% chlorhexidine gluconate.

Properties of Experimental Dental Composites Containing Antibacterial Silver-Releasing Filler. Materials 2018, 11, 1031.

In the published article, "Properties of Experimental Dental Composites Containing Antibacterial Silver-Releasing Filler" [...].

Properties of Experimental Dental Composites Containing Antibacterial Silver-Releasing Filler.

Secondary caries is one of the important issues related to using dental composite restorations. Effective prevention of cariogenic bacteria survival may reduce this problem. The aim of this study was to evaluate the antibacterial activity and physical properties of composite materials with silver sodium hydrogen zirconium phosphate (SSHZP). The antibacterial filler was introduced at concentrations of 1%, 4%, 7%, 10%, 13%, and 16% (w/w) into model composite material consisting of methacrylate monomers and silanized glass and silica fillers. The in vitro reduction in the number of viable cariogenic bacteria Streptococcus mutans ATCC 33535 colonies, Vickers microhardness, compressive strength, diametral tensile strength, flexural strength, flexural modulus, sorption, solubility, degree of conversion, and color stability were investigated. An increase in antimicrobial filler concentration resulted in a statistically significant reduction in bacteria. There were no statistically significant differences caused by the introduction of the filler in compressive strength, diametral tensile strength, flexural modulus, and solubility. Statistically significant changes in degree of conversion, flexural strength, hardness (decrease), solubility (increase), and in color were registered. A favorable combination of antibacterial properties and other properties was achieved at SSHZP concentrations from 4% to 13%. These composites exhibited properties similar to the control material and enhanced in vitro antimicrobial efficiency.

Effect of Silver-Emitting Filler on Antimicrobial and Mechanical Properties of Soft Denture Lining Material.

Colonization of silicone-based soft lining materials by pathogenic yeast-type fungi is a common problem associated with the use of dentures. In this study, silver sodium hydrogen zirconium phosphate (SSHZP) was introduced into polydimethylsiloxane-based material as an antimicrobial filler at concentrations of 0.25, 0.5, 1, 2, 4, 6, 8, 10, 12, and 14% (w/w). The in vitro antimicrobial efficacy was investigated. Candida albicans was used as a characteristic representative of pathogenic oral microflora. Staphylococcus aureus and Escherichia coli were used as the typical Gram-positive and Gram-negative bacterial strains, respectively. The effect of filler addition on the Shore A hardness, tensile strength, tensile bond strength, sorption, and solubility was investigated. An increase in the filler concentration resulted in an increase in hardness, sorption, and solubility, and for the highest concentration, a decrease in bond strength. The favorable combination of antimicrobial efficacy with other properties was achieved at filler concentrations ranging from 2% to 10%. These composites exhibited mechanical properties similar to the material without the antimicrobial filler and enhanced in vitro antimicrobial efficiency.

Effect of Storage in Distilled Water for Three Months on the Antimicrobial Properties of Poly(methyl methacrylate) Denture Base Material Doped with Inorganic Filler.

The colonization of poly(methyl methacrylate) (PMMA) denture base materials by pathogenic microorganisms is a major problem associated with the use of prostheses, and the incorporation of antimicrobial fillers is a method of improving the antimicrobial properties of these materials. Numerous studies have demonstrated the initial in vitro antimicrobial effectiveness of this type of material; however, reports demonstrating the stability of these fillers over longer periods are not available. In this study, silver sodium hydrogen zirconium phosphate was introduced into the powder component of a PMMA denture base material at concentrations of 0.25%, 0.5%, 1%, 2%, 4%, and 8% (w/w). The survival rates of the gram-positive bacterium Staphylococcus aureus, gram-negative bacterium Escherichia coli and yeast-type fungus Candida albicans were established after fungal or bacterial suspensions were incubated with samples that had been previously stored in distilled water. Storage over a three-month period led to the progressive reduction of the initial antimicrobial properties. The results of this study suggest that additional microbiological tests should be conducted for materials that are treated with antimicrobial fillers and intended for long-term use. Future long-term studies of the migration of silver ions from the polymer matrix and the influence of different media on this ion emission are required.

Influence of the toothpaste with brazilian ethanol extract propolis on the oral cavity health.

Propolis-based therapeutic agents represent this potential for the development of new drugs in dental care. The aim of a clinical-cohort study was to determine the influence of application of toothpaste enriched with Brazilian extract of propolis (EEP) on health status of oral cavity. Laboratory analysis was conducted in order to assess the chemical composition of EEP including total phenolic compounds, the DPPH (1,1-diphenyl-2-picrylhydrazyl) radical scavenging activity, ABTS radical cation scavenging activity, and FRAP assay. Clinical research involved two groups of subjects comprising 32 adult patients, with assessment based on the preliminary evaluation of the state of their marginal periodontium. The investigation of oral health indices API, OHI, and SBI and microbiological examination of oral microflora were also carried out. Results obtained indicated time-dependent microbial action of EEP at 50 mg/L concentration, with antimicrobial activity against Gram-positive bacteria. The total decrease of API, OHI, and SBI mean values was observed. Hygienic preparations with 3% content of Brazilian ethanol extract of green propolis (EEP) efficiently support removal of dental plaque and improve the state of marginal periodontium.