Effects of natural products-based dentifrices on acrylic resin for denture bases: A simulated period of 4 years.

PURPOSE: To evaluate the antimicrobial activity of dentifrices based on Malva sylvestris and propolis and the effect on the acrylic resin. METHODS: The inhibitory effect against Candida albicans, Enterococcus faecalis and Streptococcus mutans was determined. The specimens of resin were divided into groups: Control (brushing with distilled water); brushing with Colgate; brushing with Protex; brushing with Malvatricin, brushing with Proporalcare Dental Gel and brushing with Green Propolis Dental Gel. Brushing was carried out in a brushing machine. Roughness and color were assessed. The data were analyzed by ANOVA, followed by the Bonferroni post test (α= 0.05). RESULTS: The products evaluated showed antimicrobial activity against all microorganisms (P< 0.05), except Proporalcare Dental Gel, which was not effective against E. faecalis. Greater roughness (P< 0.05) was observed in the samples treated with Colgate. The samples from control and Protex groups showed the lowest color variation and the highest luminosity, with a difference in relation to the others (P< 0.05), which showed higher values, although clinically acceptable. CLINICAL SIGNIFICANCE: The dentifrices based on natural products can be indicated for cleaning prostheses, since they showed antimicrobial activity and did not cause perceptible color changes of the resin tested. The dentifrices did not produce adverse effects on the surface of the resin or did so less than the conventional dentifrice.

Effect of disinfectants on multispecies biofilm, the physical and mechanical properties of polymethyl methacrylate, and the corrosion of cobalt chromium alloy.

STATEMENT OF PROBLEM: The optimal disinfection protocol that controls adverse effects and promotes effective antimicrobial action on removable prostheses is unclear. PURPOSE: This in vitro study investigated the effect of disinfectant solutions on the biological, physical, mechanical, and chemical properties of removable prosthesis materials. MATERIAL AND METHODS: Specimens of polymethyl methacrylate (PMMA) and cobalt chromium (Co-Cr) alloy were immersed in distilled water (PMMA) or artificial saliva (Co-Cr) as the control and in 0.25% sodium hypochlorite (NaOCl0.25%), 0.5% chloramine T (CT0.5%), and 0.15% Triclosan (TR0.15%). The antibiofilm activity was evaluated by microbial load and cell metabolisms of the mixed biofilm. Physical (color change, sorption, solubility, and surface roughness), mechanical (hardness, flexural, and impact strength), and chemical (corrosion) properties were analyzed before and after simulating a 5-year immersion. Laser confocal microscopy, scanning electron microscopy (SEM), and dispersive energy spectroscopy (EDS) complemented the analyses. The data were analyzed by using the Mann-Whitney U test, Kruskal-Wallis with Dunn posttests, 1-way ANOVA, and repeated measures ANOVA (α=.05). RESULTS: All solutions were effective against bacteria, but only NaOCl0.25% eliminated Candida spp. TR0.15%, and CT0.5% increased cell metabolisms. For interaction (time and solution), there was a reduction in PMMA hardness in the control and TR0.15%. Color, sorption, solubility, and flexural strength did not change. CT0.5% and TR0.15% were similar for impact resistance. CT0.5% caused the lowest roughness. NaOCl0.25% showed the greatest corrosive potential. Dark spots were seen under SEM in Co-Cr stored with NaOCl0.25% and TR0.15%. EDS indicated different proportions of oxygen, cobalt, chromium, and molybdenum. CONCLUSIONS: NaOCl0.25% had the best antimicrobial action. CT0.5% and TR0.15% have potential. Hardness and roughness changes were clinically acceptable, and the other properties remained unchanged. All the solutions caused color changes. NaOCl0.25% was unsatisfactory for use with Co-Cr, CT0.5% was intermediate, and TR0.15% was suitable.

Action of chitosan-based solutions against a model four-species biofilm formed on cobalt-chromium and acrylic resin surfaces.

OBJECTIVE: To evaluate the anti-biofilm action of chitosan, nanoparticulate chitosan, and denture cleanser Nitradine™ against biofilms comprising Candida albicans, Candida glabrata, Staphylococcus aureus, and Streptococcus mutans. BACKGROUND: Biofilm removal from removable partial dentures (RPD) is important for success in prosthetic rehabilitation. MATERIALS AND METHODS: The anti-biofilm action of the experimental chitosan-based solutions and Nitradine™ was evaluated on acrylic resin and cobalt-chromium alloy through assessing cell viability, cell metabolism, residual aggregated biofilm, and extracellular polymeric substance and biofilm morphology. RESULTS: Only chitosan reduced the viability of C. albicans on cobalt-chromium alloy surface, by 98% (a 1.7 log10 reduction in cfu). Chitosan-based solutions neither promoted substantial alteration of the metabolic activity of the four-species biofilm nor reduced the amount of the aggregated biofilm. After immersion in chitosan and nanoparticulate chitosan, viable microorganisms and extracellular polymeric substances distributed over the entire specimens' surfaces were observed. Nitradine™ reduced the viability and metabolic activity of biofilm grown on both surfaces, but it did not remove all aggregated biofilm and extracellular polymeric substances. After immersion in Nitradine™, approximately 35% of the specimens' surfaces remained covered by aggregated biofilm, mainly composed of dead cells. CONCLUSION: Although chitosan and Nitradine™ promoted changes in the viability of microorganisms, neither solution completely removed the four-species biofilm from the Co-Cr and acrylic resin surfaces. Thus, isolated use of hygiene solutions is not indicated for biofilm control on RPDs; this requires complementary mechanical removal.

Protocol with non-toxic chemicals to control biofilm in dental unit waterlines: physical, chemical, mechanical and biological perspective.

Biosafety in dentistry aims to combat cross-contamination and biofilm in dental unit waterlines. The aim was to investigate from a physical, chemical, mechanical and biological perspective, a protocol for using chemical products (citric acid, sodium bicarbonate and sodium chloride) to improve and maintain water quality in dental unit waterlines. Change in microhardness and corrosion tendency were observed in stainless steel samples. On the polyurethane surfaces, there were changes in color, microhardness and roughness. Anti-biofilm evaluations revealed a significant reduction in the biofilm biomass, metabolic activity and residual biofilm. These findings suggest that the protocol analyzed in this study showed an innovative potential against biofilm in dental unit waterlines, preserving the physical, chemical and mechanical properties of the materials.

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.

Increased diversity, fungal burden, and virulence of oral Candida spp. in patients undergoing anti-tuberculosis treatment.

Some studies have demonstrated a high prevalence of Candida species in patients with tuberculosis (TB). This is most likely due to long-term antimicrobial therapy. To date, no longitudinal studies addressed the effects of anti-TB treatment on the fungal burden and virulence of Candida spp. This study investigated the prevalence and virulence of Candida spp. in the oral cavity of 30 TB patients at different stages of treatment through a cohort study. These results were compared with those of 60 systemically healthy individuals in a cross-sectional study. Oral rinse samples from TB patients were collected before 45 and after 120 days of treatment. In the control group, the biological samples were collected only once. Candida spp. were identified by restriction fragment length polymorphism (RFLP) assays, and the following virulence factors were studied: phospholipase C and proteinase production, as well as Candida spp. biofilm and hyphae formation. The clinical diagnosis of TB and its treatment time were associated with the greater fungal burden (p < 0.0001), presence of non-albicans Candida (NAC) species (p = 0.0003), and increased virulence factors when compared with the Candida spp. isolated from systemically healthy individuals. The results showed that anti-TB treatment time was responsible for the increased fungal burden and isolation of NAC in TB patients (p = 0.0233). The increased prevalence, quantification, and virulence of Candida spp. isolated from the oral cavity of TB patients highlight the greater risk of oral lesions and cases of systemic dissemination in these patients.

Expression of virulence factors by Pseudomonas aeruginosa biofilm after bacteriophage infection.

The use of bacteriophages for the treatment of bacterial infections has been extensively studied. Nonetheless, the stress response regarding bacteriophage infection and the expression of virulence factors of Pseudomonas aeruginosa after phage infection is poorly discussed. In this study, we evaluated biofilm formation capacity and expression of virulence factors of P. aeruginosa after bacteriophage infection. Biofilm growth rates, biofilm morphology, pyocyanin production and elastase activity were evaluated after 2, 8, 24 and 48 h of co-cultivation with bacteriophages that was recently characterized and showed to be infective towards clinical isolates. In parallel, quantitative real-time polymerase chain reactions were carried out to verify the expression of virulence-related genes. Bacteriophages promoted substantial changes in P. aeruginosa biofilm growth at early co-culture time. In addition, at 8 h, we observed that some cultures developed filaments. Although bacteriophages did not alter both pyocyanin and protease activity, changes on the expression level of genes related to virulence factors were detected. Usually, lasI, pslA, lasB and phzH genes were upregulated after 2 and 48 h of co-culture. These results highlight the need for extensive investigation of pathways and molecules involved in phage infection, since the transcriptional changes would suggest a response activation by P. aeruginosa.

Biomaterials for orthopedics: anti-biofilm activity of a new bioactive glass coating on titanium implants.

This study evaluated adhesion and biofilm formation by Candida albicans, Pseudomonas aeruginosa and Staphylococcus epidermidis on surfaces of titanium (Ti) and titanium coated with F18 Bioactive Glass (BGF18). Biofilms were grown and the areas coated with biofilm were determined after 2, 4 and 8 h. Microscopy techniques were applied in order to visualize the structure of the mature biofilm and the extracellular matrix. On the BGF18 specimens, there was less biofilm formation by C. albicans and S. epidermidis after incubation for 8 h. For P. aeruginosa biofilm, a reduction was observed after incubation for 4 h, and it remained reduced after 8 h on BGF18 specimens. All biofilm matrices seemed to be thicker on BGF18 surface than on titanium surfaces. BGF18 showed significant anti-biofilm activity in comparison with Ti in the initial periods of biofilm formation; however, there was extensive biofilm after incubation for 48 h.

Efficacy of a propolis solution for cleaning complete dentures.

PURPOSE: The efficacy of a propolis solution against denture biofilm was evaluated by means of an in vitro assessment and a cross-over randomized clinical trial. METHODS: Acrylic resin specimens were contaminated by Staphylococcus aureus, Streptococcus mutans, Escherichia coli, Candida albicans, Candida glabrata, Candida parapsilosis, immersed in a (A) propolis solution, (B) saline or (C) alkaline peroxide, applied onto Petri plates with culture medium and after incubation the number of colonies was counted. For the clinical trial, 30 complete denture wearers were randomly assigned to groups (A) propolis solution, and (B) saline, following one of the sequences (I)A/B or (II) B/A. After each intervention, biofilm was quantified by means of digital photos taken from the intaglio surface and a microbiological quantification of Candida spp. and mutans streptococci was conducted. RESULTS: Both propolis solution and alkaline peroxide reduced the microbial counts for S. mutans and C. albicans with significant and greater effect for group C (P< 0.05). However, no difference was found clinically between the interventions. The propolis solution showed an intermediate antimicrobial effect against S. mutans and C. albicans. Also, it did not exert an immediate effect on denture biofilm. CLINICAL SIGNIFICANCE: A commercially available propolis-based cleanser solution was evaluated in vitro and clinically for the treatment of denture stomatitis. Although an immediate effect on denture biofilm was not observed after a single application, It showed antimicrobial effect against S. mutans and C. albicans.

Genomic identification of microbial species adhering to maxillofacial prostheses and susceptibility to different hygiene protocols.

This study investigated the microbial colonization of maxillofacial prostheses and support tissues using the Checkerboard DNA-DNA hybridization method, and the efficacy of 0.12% chlorhexidine gluconate, 10% Ricinus communis solutions, or brushing, on colony forming unit (CFU) reduction in monospecies biofilms (Candida glabrata, Staphylococcus aureus, Streptococcus mutans, Escherichia coli, Enterococcus faecalis, and Pseudomonas aeruginosa) formed on two silicones (MDX 4-4210 and Bio-Skin). Biofilm was harvested from 43 maxillofacial prosthesis wearers for detection of 38 species of microorganisms. The CFU counts of the six above mentioned species were recorded after using the hygiene protocols. All 38 investigated species were identified in prostheses and tissues, with a higher prevalence in the prostheses. 0.12% chlorhexidine gluconate immersion showed the greatest antimicrobial effectiveness, followed by mechanical brushing protocols. MDX 4-4210 silicone produced lower CFU counts than Bio-Skin.

Influence of pre-irradiation time employed in antimicrobial photodynamic therapy with diode laser.

The aim of the present study was to evaluate, in vitro, the effect of different pre-irradiation times of the photosensitizer in photodynamic therapy in biofilms formed by Streptococcus mutans and Candida albicans, through the evaluation of the microbial load. The factors under study were as follows: times of pre-irradiation of the photosensitizer in three levels (1, 2, or 5 min). For the control of the cariogenic dental biofilm with antimicrobial photodynamic therapy (aPDT), methylene blue (0.01%) was used in association with the diode laser (InGaAlP) with a wavelength of 660 nm. Chlorhexidine digluconate (0.12% CHX) and saline were used as positive and negative controls, respectively. The study design was carried out in complete and randomized blocks. The sample consisted of 15 S. mutans biofilms cultures, randomly divided into five groups and 15 C. albicans cultures, also divided into five groups. The experiment was performed in triplicate (n = 3) and the response variables were obtained through quantitative analysis of bacterial viability, expressed in colony-forming units (CFU) per square millimeter of the specimen area. The data were analyzed with the aid of the ANOVA one-way test and Tukey's post-test. All analyses were performed using the Graph Pad Prism 4.0 program, with a significance level of 5%. For the S. mutans group, only the saline solution presented a statistically significant difference when compared to the other treatments (p < 0.05), that is, the treatment with aPDT, irrespective of the irradiation time applied, was similar to the treatment with CHX and both were more effective in reducing cariogenic biofilm compared to saline. For the group of C. albicans, there was no statistical difference between the groups (p > 0.05). Therefore, it can be concluded that the treatment with aPDT reduced the number of CFUs of S. mutans in a similar way to CHX, independently of the pre-irradiation time applied. No effect of this therapy or of the different pre-irradiation times on the C. albicans biofilm could be observed. In this way, the pre-irradiation time of 1 min can be used to reduce the microbial load of S. mutans.

Surface treatment of implant materials with antimicrobial nanoparticulates.

This study analyzed nanostructured silver vanadate (AgVO3) films on certain substrate surfaces found in dental implant devices in order to see if these films promote antimicrobial activity. Enamel and glaze vehicles were used to apply the nanomaterial (0.0% [control], 2.5%, 5.0%, and 10.0% concentrations) on 3 substrates (280 specimens per substrate): polytetrafluoroethylene (PTFE), polyacetal, and acrylic resin. An agar diffusion method was performed in triplicate to determine the antimicrobial activity against 8 microorganisms. Physical behavior and morphologic properties were also analyzed. The growth of Pseudomonas aeruginosa, Escherichia coli, Streptococcus mutans, Enterococcus faecalis, and Staphylococcus aureus was inhibited with the application of AgVO3. For Candida albicans, Porphyromonas gingivalis, and Prevotella intermedia, no antimicrobial activity was observed. Except for S mutans, the type of substrate did not influence the microbiologic results. The glaze showed greater antimicrobial efficacy against S aureus, E faecalis, and S mutans than did the enamel vehicle (P < 0.05). Films with 10% AgVO3 showed greater antimicrobial activity (P < 0.05). The choice of substrate or vehicle did not influence the surface roughness (P > 0.05); however, the application of 10% AgVO3 caused greater surface change (P < 0.05). The application of the nanomaterial did not influence the surface hardness of substrates when compared with the control group (P > 0.05). The use of the glaze as a vehicle provided higher hardness values (P < 0.05).

Antimicrobial action and long-term effect of overnight denture cleansers.

PURPOSE: To evaluate two denture cleansers for overnight soaking (0.5% sodium hypochlorite and peroxide alkaline) regarding efficacy against Candida spp. biofilms (randomized clinical trial) and their effects on the physical properties of a denture base acrylic resin simulating a period of 5 years of use (laboratory study). The Candida spp. were identified and their resistance to main antifungal agents was evaluated. METHODS: 32 complete denture wearers were instructed to brush their dentures three times a day and to soak them (≥8 hours) in: control - water (C); alkaline peroxide (AP); or 0.5% sodium hypochlorite (SH). According to a randomized sequence, each solution was used for three alternate periods of 7 days. The antimicrobial action was performed by counting the colony forming units (CFU) of Candida spp. For collection of the biofilm, each upper complete denture was placed in a Petri dish, the internal surface was brushed (Tek brush) with saline solution for 2 minutes and the suspension was transferred to a test tube. After dilutions (10 0 to 10-3), aliquots of 50 µL were seeded inside Petri dishes containing Candida Chromagar. After incubation, the colonies were counted and the values of CFU/mL calculated. Data were transformed in log10 (CFU +1) and analyzed by the Friedman test (α= 0.05) followed by Wilcoxon and Bonferroni tests (α= 0.05). Each of the different species identified perfunctorily has been confirmed through the identification of yeasts kit. The resistance to antifungal agents (amphotericin B, nystatin, flucytosine, econazole, ketoconazole, miconazole and fluconazole) was also evaluated. Adverse effects were estimated on heat-polymerized resin specimens, simulating a 5-year period of overnight use. Acrylic resin specimens were randomly distributed into three groups: C: Control (distilled water); AP: alkaline peroxide; and SH: 0.5% sodium hypochlorite. Color change, surface roughness and flexural strength were evaluated at baseline and after immersion procedures. Data were compared by Kruskall-Wallis followed by Dunn's test (color change and surface roughness) and one-way ANOVA (flexural strength) (α= 0.05). RESULTS: There was a reduction of Candida spp. counts after using both solutions (AP and SH). The Candida spp. most often isolated was C. albicans, followed by the C. glabrata. Only 24.7% of isolate strains were resistant to at least one of the tested antifungals, highlighting azole compounds. Immersion in AP [ 5.73 (5.45-5.91)] caused significantly higher color change, with lower ΔE values for C [1.12 (1.15-1.37) ] followed by SH [3.70 (3.51-3.98) ]. The NBS values were classified as "slight" for C (1.12) group and " considerable" for AP (5.27) and SH (3.40). No solution altered surface roughness significantly. Flexural strength (in MPa) was significantly lower for C (64.59), AP (63.96 ± 12.98) and SH (62.84 ± 8.62) when compared to a group without any immersion (109.12 ± 8.37). CLINICAL SIGNIFICANCE: Both solutions tested presented antimicrobial action against Candida spp. and may be useful for denture biofilm control, but should be used with caution as an overnight immersion solution since they may damage denture bases in the long-term. Candida was most frequently isolated at baseline and after using the products. Only 24.7% of isolate strains were resistant to at least one of the tested antifungals, especially with azole compounds.

Effect of Liquid Crystalline Systems Containing Antimicrobial Compounds on Infectious Skin Bacteria.

This study aimed (i) to prepare liquid crystalline systems (LCS) of glyceryl monooleate (GMO) and water containing antibacterial compounds and (ii) to evaluate their potential as drug delivery systems for topical treatment of bacterial infections. Therefore, LCS containing CPC (cetylpyridinium chloride) (LCS/CPC) and PHMB (poly(hexamethylene biguanide) hydrochloride) (LCS/PHMB) were prepared and the liquid crystalline phases were identified by polarizing light microscopy 24 h and 7 days after preparation. The in vitro drug release profile and in vitro antibacterial activity of the systems were assessed using the double layer agar diffusion method against Staphylococcus aureus, methicillin-resistant S. aureus, Staphylococcus epidermidis, Escherichia coli, and Enterococcus faecalis. The interaction between GMO and the drugs was evaluated by a drug absorption study. Stable liquid crystalline systems containing CPC and PHMB were obtained. LCS/PHMB decreased the PHMB release rate and exerted strong antibacterial activity against all the investigated bacteria. In contrast, CPC interacted with GMO so strongly that it became attached to the system; the amount released was not sufficient to exert antibacterial activity. Therefore, the studied liquid crystalline systems were suitable to deliver PHMB, but not CPC. Accordingly, it was demonstrated that GMO interacts with each drug differently, which may interfere in the final efficiency of GMO/water LCS.

In vitro study of the antibacterial properties and impact strength of dental acrylic resins modified with a nanomaterial.

STATEMENT OF PROBLEM: The accumulation of bacteria on the surface of dental prostheses can lead to systemic disease. PURPOSE: The purpose of this in vitro study was to evaluate the growth of Staphylococcus aureus and Pseudomonas aeruginosa on the surface of autopolymerizing (AP) and heat-polymerizing (HP) acrylic resins incorporated with nanostructured silver vanadate (ß-AgVO3) and its impact strength. MATERIAL AND METHODS: For each resin, 216 circular specimens (9 × 2 mm) were prepared for microbiologic analysis and 60 rectangular specimens (65 × 10 × 3.3 mm) for mechanical analysis, according to the percentage of ß-AgVO3: 0%, control group; 0.5%; 1%; 2.5%; 5%; and 10%. After a biofilm had formed, the metabolic activity of the bacteria was measured using the XTT reduction assay (2,3-bis-(2-methoxy-4-nitro-5-sulfophenyl)-2H-tetrazolium-5-carboxanilide) (n=8), and the number of viable cells was determined by counting colony forming units per milliliter (CFU/mL) (n=8). Confocal laser scanning microscopy (CLSM) was used to complement the analyses (n=2). The mechanical behavior was evaluated by impact strength assays (n=10). Data were analyzed by 2-way ANOVA, followed by the Tukey honestly significant difference (HSD) post hoc test (α=.05). RESULTS: The addition of 5% and 10% ß-AgVO3 significantly decreased the metabolic activity of P. aeruginosa for both resins (P<.05). The HP resin promoted a greater reduction in metabolic activity than the AP resin (P<.05). No difference was found in the metabolic activity of S. aureus according to the XTT (P>.05). The number of CFU/mL for S. aureus and P. aeruginosa decreased significantly when 5% and 10% ß-AgVO3 were added (P<.001). These concentrations significantly reduced the impact strength of the resins (P<.001) because the system was weakened by the presence of clusters of ß-AgVO3. CONCLUSION: The addition of ß-AgVO3 can provide acrylic resins with antibacterial activity but reduces their impact strength. More efficient addition methods should be investigated.

Effectiveness of three antimicrobial mouthrinses on the disinfection of toothbrushes stored in closed containers: a randomized clinical investigation by DNA Checkerboard and Culture.

OBJECTIVES: The aim of this in vivo study was to evaluate the efficacy of three antimicrobial solutions on the disinfection of toothbrushes after storage in closed containers. MATERIALS AND METHODS: Sixteen healthy subjects were enrolled in this randomized cross-over clinical investigation. The study was conducted in four phases, in which mouthrinses (chlorhexidine gluconate-based or cetilpiridinium-based) and sterile tap water (control group) were used to individually store used toothbrushes in closed containers during 7 days of toothbrushing. Five toothbrushes were used as negative control for bacterial colonisation before contact with oral cavity. Conventional culture and DNA Checkerboard hybridization were used to detect bacterial contamination on the toothbrushes. Subsequently, the number of bacterial species on the bristles was estimated by the DNA Checkerboard method. RESULTS: One toothbrush presented bacterial contamination in the negative control test. Both culture and DNA Checkerboard showed positive signals of bacterial contamination in the toothbrushes with no differences in the frequency of detection. The control group showed higher total bacterial counts when compared with the mouthrinse groups. Porphyromonas gingivalis had the highest bacterial count followed by Parvimonas micra. CONCLUSION: Culture and DNA Checkerboard showed positive signals of bacterial contamination. Mouthrinses that contains 0.12% of chlorhexidine gluconate were more effective in reducing bacterial colonisation on the toothbrushes.

[Collection of tracheal aspirate: safety and microbiological concordance between two techniques]. / Colheita de aspirado traqueal: segurança e concordâcia microbiológica entre duas técnicas.

OBJECTIVE: To evaluate the safety of the performance of the traditional and protected collection techniques of tracheal aspirate and to identify qualitative and quantitative agreement of the results of microbiological cultures between the techniques. METHOD: Clinical, prospective, comparative, single-blind research. The sample was composed of 54 patients of >18 years of age, undergoing invasive mechanical ventilation for a period of ≥ 48 hours and with suspected Ventilator Associated Pneumonia. The two techniques were implemented in the same patient, one immediately after the other, with an order of random execution, according to randomization by specialized software. RESULTS: No significant events occurred oxygen desaturation, hemodynamic instability or tracheobronchial hemorrhage (p<0.05) and, although there were differences in some strains, there was qualitative and quantitative agreement between the techniques (p<0.001). CONCLUSION: Utilization of the protected technique provided no advantage over the traditional and execution of both techniques was safe for the patient.

Enhancing Removable Partial Dentures Hygiene: Investigating Mucolytic Agents and Biocides for Disrupting Biofilms and Improving Antimicrobial Efficacy.

PURPOSE: This study evaluates the antibiofilm action of 2.5 mg/mL peracetic acid (PA), 0.5 mg/mL cetylpyridinium chloride (CPC), and 160 mg/mL N-Acetylcysteine (NAC) against multispecies biofilm of Streptococcus mutans, Staphylococcus aureus, Candida albicans, and Candida glabrata, developed on surfaces of heat-polymerizing acrylic resin (AR) and cobaltchromium (Co-Cr) alloy. MATERIALS AND METHODS: A multispecies biofilm was grown on the surface of AR and Co-Cr specimens (Ø 12×3mm). After biofilm maturation, the specimens were immersed in experimental solutions and evaluated through biofilm viability (CFU) (n=9), biofilm metabolic activity (XTT) (n=9), biofilm-covered areas (Live/Dead) (n=2), effects on the extracellular polymeric substance (EPS) (n=2) and biofilm morphology (n=1). Data were analyzed by ANOVA and the Tukey post-test or Kruskal-Wallis followed by the Dunn post-test (α=.05). RESULTS: Overall, all evaluated solutions impacted biofilm viability. PA presented wider activity by reducing CFU of all microorganisms on both surfaces, XTT (P<.001) and Live/Dead (P<.001). NAC had a notorious effect in reducing the viability of bacteria without affecting the yeasts. NAC reduced XTT on AR (P=.006) and Co-Cr (P=.003) but did not reduce the aggregated biofilm layer. CPC had distinct effect according to the surface, being most effective in reducing CFU on AR than the Co-Cr surface. However, it did not influence XTT, and the amount of residual aggregated biofilm. CONCLUSIONS: PA provided the greatest antibiofilm action, while CPC and NAC showed intermediate action. Nonetheless, no solution was able to completely remove the biofilm adhered to the surfaces of heat-polymerizing AR and Co-Cr alloy.

Assessment of peripheral venous catheters microbiota and its association with phlebitis.

BACKGROUND: Peripheral venous catheters (PVCs) remain the primary mode of short-term venous access for managing intravenous fluid, obtaining blood samples, and peripheral parenteral nutrition. They may get contaminated and require regular monitoring to prevent complications. This study evaluated the occurrence of phlebitis and its associated-clinical and microbiological indicators. METHODS: The frequency of phlebitis was evaluated in hospitalized patients of both medical and surgical fields. Subsequently, the dichotomous association between the presence of phlebitis and the clinical aspects was investigated. In parallel, the bacterial contamination of PVCs was assessed through culture-based methods, microscopy observation, and 16S rRNA gene sequencing. RESULTS: Approximately one in four patients presented phlebitis (28.4%). The most frequent symptom was erythema at access site, with or without pain, corresponding to Score 1 on the phlebitis scale (17.9%). Colonization of both lumen and external surface of PVC was observed in 31.3% of the samples. Staphylococcus and Pseudomonas were the most isolated bacterial genera on the PVC surface. No significant association was observed between the presence of phlebitis and the clinical aspects, as well as the presence of microorganisms. CONCLUSION: Microorganism were present on both internal and external PVC surface, without being associated to phlebitis.

The implications of healthcare professionals wearing jewelry on patient care biosafety: observational insights and experimental approaches.

The use of jewelry among healthcare professionals poses a risk of cross contamination due to potential bacterial accumulation and spread. Through a mixed-method design, this study first analyzed the implications of healthcare professionals wearing jewelry on patient care biosafety as well as on the residual bacterial load of hands and rings after hand hygiene. Firstly, an observational prevalence study to verify whether nursing professionals wear personal accessories during healthcare assistance was carried out. Second, an experimental design involving intentional contamination and hygiene of the hands, with and without a ring, was conducted. The bacterial load of both hands and rings was measured by counting colony forming units. The observational study showed that nursing workers frequently wear jewelry during healthcare assistance. Nonetheless, the experimental study did not indicate differences in bacterial contamination between hands with and without a ring, despite the hand hygiene procedure applied. In conclusion, many nursing workers wear jewelry in the workplace. Although hands with and without a ring exhibited similar microbial load, rings appeared as a potential source of bacterial contamination, reinforcing the need to remove jewelry during working hours. Hand hygiene using alcohol, or soap and water significantly decreased the bacterial load on the participants' hands, with handwashing proving to be the most efficient method for removing intentional contamination.