The Effect of Exposure to Candida Albicans Suspension on the Properties of Silicone Dental Soft Lining Material.

While functioning in the oral cavity, denture soft linings (SL) are exposed to contact with the microbiota. Dentures can offer perfect conditions for the multiplication of pathogenic yeast-like fungi, resulting in rapid colonisation of the surface of the materials used. In vitro experiments have also shown that yeast may penetrate SL. This may lead to changes in their initially beneficial functional properties. The aim of this work was to investigate the effect of three months of exposure to a Candida albicans suspension on the mechanical properties of SL material and its bond strength to the denture base polymer, and to additionally verify previous reports of penetration using a different methodology. Specimens of the SL material used were incubated for 30, 60 and 90 days in a suspension of Candida albicans strain (ATCC 10231). Their shore A hardness, tensile strength, and bond strength to acrylic resin were tested. The colonization of the surface and penetration on fractured specimens were analysed with scanning electron and inverted fluorescence microscopes. Exposure to yeast did not affect the mechanical properties. The surfaces of the samples were colonised, especially in crystallized structures of the medium; however, the penetration of hyphae and blastospores into the material was not observed.

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.

A Temporary Acrylic Soft Denture Lining Material Enriched with Silver-Releasing Filler-Cytotoxicity, Mechanical and Antifungal Properties.

Colonization of temporary denture soft linings and underlying tissues by yeast-like fungi is an important clinical problem due to the negative influence on the process of prosthetic treatment. Typical hygienic procedures are often insufficient to prevent fungal infections, so in this study, an antimicrobial filler (silver sodium hydrogen zirconium phosphate) was introduced into acrylic soft liner at concentrations of 1, 2, 4, 6, 8 and 10% (w/w). The effect of this modification on antifungal properties against Candida albicans, cytotoxicity, Shore A hardness, tensile strength and tensile bond strength, sorption and solubility was investigated, considering the recommended 30-day period of temporary soft lining use. The most favorable compilation of properties was obtained at a 1 to 6% filler content, for which nearly a total reduction in Candida albicans was registered even after 30 days of sample storing. The tensile and bond strength of these composites was at the desired and stable level and did not differ from the results for the control material. Hardness increased with the increasing concentration in filler but were within the range typical for soft lining materials and their changes during the experiment were similar to the control material. The materials were not cytotoxic and sorption and solubility levels were stable.

The effect of quaternary ammonium polyethylenimine nanoparticles on bacterial adherence, cytotoxicity, and physical and mechanical properties of experimental dental composites.

A significant problem related to the functioning of resin-based composites for dental fillings is secondary or recurrent caries, which is the reason for the need for repeated treatment. The cross-linked quaternary ammonium polyethylenimine nanoparticles (QA-PEI-NPs) have been shown to be a promising antibacterial agent against different bacteria, including cariogenic ones. However, little is known about the properties of dental dimethacrylate polymer-based composites enriched with QA-PEI-NPs. This research was carried out on experimental composites based on bis-GMA/UDMA/TEGDMA matrix enriched with 0.5, 1, 1.5, 2 and 3 (wt%) QA-PEI-NPs and reinforced with two glass fillers. The cured composites were tested for their adherence of Streptococcus Mutans bacteria, cell viability (MTT assay) with 48 h and 10-days extracts , degree of conversion (DC), water sorption (WSO), and solubility (WSL), water contact angle (CA), flexural modulus (E), flexural strength (FS), compressive strength (CS), and Vickers microhardness (HV). The investigated materials have shown a complete reduction in bacteria adherence and satisfactory biocompatibility. The QA-PEI-NPs additive has no effect on the DC, VH, and E values. QA-PEI-NPs increased the CA (a favorable change), the WSO and WSL (unfavorable changes) and decreased flexural strength, and compressive strength (unfavorable changes). The changes mentioned were insignificant and acceptable for most composites, excluding the highest antibacterial filler content. Probably the reason for the deterioration of some properties was low compatibility between filler particles and the matrix; therefore, it is worth extending the research by surface modification of QA-PEI-NPs to achieve the optimum performance characteristics.

The Impact of COVID-19 on the Oral Bacterial Flora in Patients Wearing Complete Dentures and on the Level of Exhaled Nitric Oxide as a Marker of Inflammation.

BACKGROUND: Exhaled nitric oxide is helpful in the diagnosis of the inflammation process. The study aimed to analyze the impact of the COVID-19 disease on the oral bacterial flora of patients using complete dentures with a diagnostic device that measures the level of NO in exhaled air. MATERIALS AND METHODS: The study included patients using upper and lower acrylic complete dentures. All patients participating in the study were vaccinated against COVID-19. The patients were divided into two groups. A dental examination was conducted in each group. The NO concentration was measured using the Vivatmo Pro device. An oral microbiological examination was performed by taking a swab from the bottom of the mouth. RESULTS: There were no statistically significant differences in the distribution of NO in relation to the number of bacteria from isolated families in the study and control groups and no statistically significant correlations between the level of NO and the number of bacteria from all families in the control and study group. Significantly higher NO values were present in the vaccinated and COVID-19-positive history population compared to the vaccinated and with no COVID-19 history population (patients with no clinical symptoms of infection or unaware they had COVID-19). CONCLUSIONS: There are statistically significant differences in NO distribution in the considered populations: vaccinated and sick, and vaccinated and with a negative history of COVID-19. The measurement of NO in exhaled air can be a complementary, non-invasive diagnostic and inflammation monitoring method.

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.

Analysis of the Validity of Perioperative Antibiotic Prophylaxis in Maxillofacial Surgery.

Perioperative antibiotic prophylaxis is the standard in surgical departments. The type of operation, the duration of the procedure, the degree of microbiological purity of the operating field and the current clinical condition of the patient determine its administration. The aim of this study was to validate the antibiotic prophylaxis used in a Maxillofacial Surgery Department for a group of trauma and non-trauma patients. To that end, an observational prospective cohort study was carried out. The study was conducted on a group of 83 patients of the Department of Cranio-Maxillo-Facial Surgery who were divided into a group of trauma patients (n = 43) and one of non-trauma patients (n = 40). In both groups, the classic microbiological tests were carried out, and the results were analyzed in relation to: the study group, age, sex, duration of surgery, type of surgical access. Most bacterial strains were isolated at the initial stage of the operation. Gram (+) cocci were isolated more often in the trauma group and Gram (-) rods in the non-trauma group. Significantly more often, strains of fungi were noted in the initial stage of the procedure in the trauma group. We conclude that the use of perioperative antibiotic prophylaxis in the Maxillofacial Surgery Departments is justified.

Status of Microbiota in Odontogenic Inflammatory Lesions and Dental Surgery Procedures Performed on an Outpatient Basis.

Inflammations of the facial part of the skull are most commonly caused by a bacterial infection. They are a frequently occurring pathological process, which results from a rich bacterial flora of the oral cavity, as well as diseased teeth and periodontal tissues. These inflammations have a primarily mixed character with the prevalence of anaerobic bacteria. Gangrene of the dental pulp is the most common odontogenic cause. In the case of inflammations of oral tissues an early and corrective treatment results in quick recovery. The purpose of this work was to assess the efficiency of empirical antibiotic therapy applied in patients with inflammations of oral tissues on the basis of a drug susceptibility profile of bacteria isolated from material extracted from inflammatory lesions. The research material consisted of smears collected from patients with existing acute inflammations in the oral cavity. The smear was collected from the bottom of the lesion after its prior surgical treatment and pus evacuation, and again, 7 days after surgery. In patients with acute odontogenic inflammations the recommended first-line therapy are extended-spectrum penicillins, characterized by a low risk of side effects and strong antimicrobial activity. In the study group, both clindamycin and amoxicillin exhibited high efficiency in treating acute odontogenic inflammatory lesions in the oral cavity.

Effect of Candida albicans Suspension on the Mechanical Properties of Denture Base Acrylic Resin.

Yeast-like fungi such as Candida albicans (C. albicans) are the primary pathogenic microorganism in the oral cavity of denture wearers. The research available so far, conducted according to a protocol based on the exposure of specimens to a C. albicans suspension and their cutting with water cooling, shows that hard polymethyl methacrylate (PMMA) prosthetic materials are not only surface colonized, but also penetrated by microorganisms in a short time. This justifies the hypothesis that exposure to a suspension of the C. albicans strain causes the changes in mechanical properties due to surface colonization and/or penetration of the samples. In the current study, the chosen mechanical properties (flexural strength, flexural modulus, tensile strength, impact strength, ball indentation hardness, and surface Vickers hardness at 300 g load) of the PMMA denture base material Vertex RS (Vertex-Dental, The Netherlands) exposed for 30, 60, and 90 days to a suspension of C. albicans were investigated. The potential penetration of yeast was examined on the fractured surfaces (interior of specimens) to eliminate the risk of the contamination of samples during cutting. There was no influence on the flexural strength, flexural modulus, tensile strength, impact strength, or ball indentation hardness, but a significant decrease in surface hardness was registered. Microscopic observations did not confirm the penetration of C. albicans. On the surface, blastospores and pseudohyphae were observed in crystallized structures and in traces after grinding, which indicates that in clinical conditions, it is not penetration but the deterioration of surface quality, which may lead to the formation of microareas that are difficult to disinfect, causing rapid recolonization.

Advantages of using toothpaste containing propolis and plant oils for gingivitis prevention and oral cavity hygiene in cleft lip/palate patients.

BACKGROUND: The anti-inflammatory and antibacterial action of preparations used during oral hygiene procedures is particularly important in patients with oral cleft. Few reports have been published assessing the influence of natural products on the state of the oral cavity in patients with oral cleft. The aim of this study was to assess the effect of toothpaste containing Polish propolis and plant oils on oral cavity health in patients with oral cleft treated orthodontically. MATERIALS AND METHODS: A total of 50 patients aged 9-16 years old (20 females, 23 males) were selected and randomly assigned into two groups. Group (A) received toothpaste with Polish propolis, tea tree oil, menthol, and rosemary oil. Group (B) received toothpaste without active ingredients (placebo). A baseline assessment was followed by an oral hygiene index (OHI, debris OHI-D, and calculus OHI-C component) and gingival bleeding index (GBI) after 35 days. The methodology of the oral condition assessment included the presence of cleft malformation as a dysmorphic of the anterior maxilla segment. RESULTS: In group A, improvement in oral cavity hygiene assessed for incisors and molars was found (OHI-T p = 0.011). For the gingival condition, a decrease in the gingival bleeding index - total (GBI-T p = 0.002), as well as for the incisors (GBI-I p = 0.007) and molars (GBI-M p = 0.017) was found. CONCLUSIONS: This research confirms the biological effectiveness of toothpaste with Polish propolis and plant oils. These results may be clinically useful for improving preventative oral care and for control of oral infectious diseases during orthodontic treatment in patients with oral cleft.

Evaluation of Effectiveness of a Toothpaste Containing Tea Tree Oil and Ethanolic Extract of Propolis on the Improvement of Oral Health in Patients Using Removable Partial Dentures.

The aim of this study was to evaluate the effect of toothpaste containing natural tea tree essential oil (TTO) and ethanolic extract of propolis (EEP), on microflora and selected indicators of oral health in patients using removable acrylic partial dentures. Fifty patients with varying conditions of hygiene were divided into two groups. The study group received the toothpaste with TTO and EEP, while the control group received the same toothpaste but without TTO and EEP. At the first visit, oral hygiene and hygiene of the prostheses were carried out. Control visits took place 7 and 28 days later and compared to baseline. Indexes like API (Approximal Plaque Index), mSBI (modified Sulcus Bleeding Index), OHI-s (simplified Oral Hygiene Index), and DPI (Denture Plaque Index) were assessed in three subsequent stages, and swabs were collected from floor of the mouth area to assess the microbiota. After 7 and 28 days of using the toothpaste with TTO and EEP, a statistically significant decrease of the examined indicator values were observed in the study group as compared to the values upon the initial visit. The number of isolated strains of microorganisms in the study group was decreased or maintained at the same level, whereas in the control group an increase in the number of isolated strains was observed. The observed stabilization of oral microbiota in patients from the study group confirms the beneficial activity of toothpaste containing EEP and TTO compared to the control group.

Study of Cytotoxic Properties of an Experimental Preparation with Features of a Dental Infiltrant.

Microinvasive dentistry is based on the treatment of early carious lesions with the use of dental infiltrants. The commercially available Icon dental infiltrant does not contain any bacteriostatic component. An experimental preparation enriched with the missing component was synthesised. The aim of this study was to evaluate the cytotoxicity of the experimental preparation. Mouse fibroblasts of the L-929 lineage were used for the in vitro study. Cell morphology and viability were assessed. In the cytotoxicity analysis, it was shown that the experimental preparation (42.8 ± 10.3) after 24 h at two-fold dilution showed similar cytotoxicity to Icon (42.7 ± 8.8) (p > 0.05), while at four-fold dilution experimental preparation (46.7 ± 3.1), it was less toxic than Icon (34.2 ± 3.1) (p < 0.05). The experimental preparation has the potential to provide an alternative to the Icon commercial preparation. Further research is needed to evaluate the cytotoxicity of the experimental preparation over a longer period of time.

Oral microbiota in children with type 1 diabetes mellitus.

INTRODUCTION: The oral cavity is a unique ecosystem in which the microbiome is formed by the colonization of billions of bacteria, viruses, and fungi. Aim of the study was to assess the quality and quantity of bacterial microbiota of the oral cavity in children with type 1 diabetes in comparison to healthy children. MATERIAL AND METHODS: The study group consisted of 50 randomly selected type 1 diabetic children aged 10-18 years divided into 2 groups (25 people each) according to the level of diabetes control: well-controlled group (WC) - HbA1c ≤ 7.5%) and poorly-controlled group (PC) - HbA1c > 7.5%. The control group (GC) consisted of 25 randomly selected children with no systemic diseases. The material for microbiological tests was collected as two swabs: one from the bottom of the oral cavity and the other one from the posterior part of the dorsum of the tongue). RESULTS: The statistical analysis revealed statistically significant differences in the total number of isolated microorganisms between PC and GC (post hoc test p = 0.003) and WC and GC (post hoc test p < 0.001). There were no statistically significant differences in the number of isolated microorganisms between PC and WC (p = 0.195). CONCLUSIONS: Oral microbiome in type 1 diabetic children is significantly quantitatively different in comparison to healthy children. There are also visible qualitative differences in the profile of oral microbiota in type 1 diabetic children and healthy children.

Effect of Weight Loss Surgery on Biomarkers of Angiogenesis in Obese Patients.

BACKGROUND: The present study aims to clarify the effects of weight loss on biomarkers associated with angiogenesis in patients who underwent laparoscopic sleeve gastrectomy (SG) or adjustable gastric banding (LAGB) in the 12-month follow-up study. MATERIALS AND METHODS: We studied 24 obese patients who underwent laparoscopic weight loss surgery, 13 of whom underwent SG and 11 of whom underwent LAGB. We evaluated the circulating level of angiogenesis biomarkers preoperatively and 12 months after surgery. RESULTS: Before surgery, the following angiogenic circulating factors were significantly higher than those of healthy subjects: angiopoietin 2 (ANG-2) (p < .05), granulocyte colony-stimulating factor (G-CSF) (p < .05), hepatocyte growth factor (HGF) (p < .01), platelet endothelial cell adhesion molecule (PECAM-1) (p < .01), and vascular endothelial growth factor (VEGF) (p < .05). The following angiogenesis biomarkers decreased significantly after weight loss compared with their baseline values: ANG-2 (p < .05), follistatin (p < .05), HGF (p < .01), PECAM-1 (p < .01), and VEGF (p < .05). There were no significant differences in the circulating levels of angiogenesis biomarkers between individuals who underwent SG and those who underwent LAGB; however, HGF, PECAM-1, and VEGF tended to be lower after SG. %BMI correlated negatively with HGF, PECAM-1, and VEGF. A similar significant negative correlation was found for %WL and %EWL. WHR correlated with PDGF-B and VEGF. CONCLUSIONS: We concluded that weight loss surgery induces the changes of circulating levels of angiogenesis biomarkers in obese patients. The changes in angiogenesis status in obese patients who lost weight after bariatric surgery depended on the amount of weight loss.

Evaluation of Drug Susceptibility of Microorganisms in Odontogenic Inflammations and Dental Surgery Procedures Performed on an Outpatient Basis.

Bacterial infections are the most common cause of purulent soft tissue inflammations in the head and neck area. These bacteria are also responsible for the majority of inflammatory complications after third molar removal. The key to success of antibacterial treatment in both cases is the use of an appropriate antibacterial agent. The aim of the study was to evaluate the susceptibility profile of bacteria isolated from material collected from patients with intraoral odontogenic abscesses. The test material consisted of swabs taken from the odontogenic abscesses, after their incision and drainage. Another swab was collected from the lesion area, 10 days after the initial visit. Results were compared with an identical study conducted on a control group of healthy patients, who had undergone third molar removal. Bacteria identified in this study consisted of aerobic and anaerobic strains, both Gram-positive and Gram-negative. According to the EUCAST guidelines, none of the tested antibiotics was recommended for all identified bacteria. The percentage of bacterial strains sensitive to amoxicillin and clavulanic acid was 78.13% and 81.48% in the study and control groups, respectively, whereas, the percentage of those sensitive to clindamycin was 96.43% and 80.00%, respectively. For Gram-negative aerobic bacteria, gentamicin and ciprofloxacin were among medications affecting all cultured species. 100.00% of strains were found to be susceptible to these antibiotics. Statistically significant relationship between the presence of Gram-negative aerobic strains and the occurrence of complications was found. In the case of the most frequently occurring bacteria in the study, amoxicillin with clavulanic acid and clindamycin were shown to be very effective. In cases of severe purulent odontogenic inflammations, it is recommended to use a combination of antibiotics. Amoxicillin with ciprofloxacin and clindamycin with cefuroxime seem to be the proper choices based on the results of this study.

The effects of venous hemodynamics on angiogenesis in morbid obese.

BACKGROUND: It is known that obesity is associated with alterations in blood rheology and venous hemodynamics. Another recent study has confirmed that adipose tissue is actively involved in angiogenesis through secretion of biologically active substances. OBJECTIVE: The aim of this study was to investigate the impact on the venous haemodynamics of the femoral vein on angiogenesis status in morbidly obese patients. METHODS: We studied venous haemodynamics and angiogenesis in a prospective study of obese and non-obese individuals. The venous wall shear stress (WSS) was calculated from the blood viscosity and the shear rate was calculated assuming Newton's law. Angiogenesis was detected using Bio-Plex Pro Human Angiogenesis Multiplex Assays (Bio-Plex 200 Systems). RESULTS: The shear rate (P < 0.000005) and the wall shear stress (P < 0.01) were significantly lower in the obese patients compared with the control subjects. All angiogenesis biomarkers were significantly higher in obese patients compared to the control group. Multivariate analyses identified waist circumference as an independent predictor for PECAM-1 (ß = - 0.69, P < 0.0001) and for VEGF (ß = - 0.60, P < 0.001); analyses identified WSS as an independent predictor for follistatin (ß = - 0.59, P < 0.001), for PECAM-1 (ß = - 036, P < 0.05) and for VEGF (ß = - 0.42, P < 0.05). For angiopoietin 2 (ß = - 0.35, P = 0.064) and HGF (ß = - 0.31, P = 0.074), WSS tended to be a significant predictor. CONCLUSIONS: The results indicated that obesity-associated decreases in shear stress of the venous system lead to upregulation of angiogenesis, expressed by increased levels of endogenous positive regulators of angiogenesis.

The relationship between the rheological behavior of RBCs and angiogenesis in the morbidly obese.

OBJECTIVE: The aim of this study was to investigate the relationship between red blood cell (RBC) aggregation and deformability and angiogenesis parameters in obese patients. METHODS: We studied 35 obese subjects and 20 non-obese people as a control group. Angiogenesis was detected using Bio-Plex Pro Human Angiogenesis Multiplex Assays. The RBC aggregation and deformability of the red blood cell aggregation were performed by the Laser-assisted Optical Rotational Cell Analyser - LORCA. RESULTS: The aggregation index and the syllectogram's amplitude were significantly higher in the obese patients, whereas the aggregation half-time (t1/2) was lower compared with the control group. The deformability of RBC expressed as EI was significantly lower in the obese group than it was in the control group. All angiogenesis parameters were higher in obese individuals than they were in the control group. Significant differences were observed in angiopoietin 2 (p = 0.048), folistin (p = 0.0017), G-CSF (p = 0.042), HGF (p = 0.016), and PECAM-1 (p = 0.014). The VEGF tended to be higher in the obese patients than in the control group (p = 0.09); nevertheless, the concentration of PDGF-BB was similar in both groups. EI at shear stresses of 18.49 Pa and 30.2 Pa was strongly correlated with all angiogenesis parameters. No correlations were found between the studied RBC aggregation indices and angiogenesis parameters. Multivariate analyses indicated that only HGF was an independent predictor of RBC deformability at 18.49 Pa (ß-0.83, P < 0.000005) and at 30.2 Pa (ß-0.83, P < 0.00005). CONCLUSIONS: The study found that there are relationships between enhanced RBC rigidity and angiogenesis status in obese subjects. Because this correlation between angiogenesis and RBC deformability is presented for the first time, the physiological importance of the relationship requires further research.

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.