Nanotopography and oral bacterial adhesion on titanium surfaces: in vitro and in vivo studies.

The present study aimed to evaluate the influence of titanium surface nanotopography on the initial bacterial adhesion process by in vivo and in vitro study models. Titanium disks were produced and characterized according to their surface topography: machined (Ti-M), microtopography (Ti-Micro), and nanotopography (Ti-Nano). For the in vivo study, 18 subjects wore oral acrylic splints containing 2 disks from each group for 24 h (n = 36). After this period, the disks were removed from the splints and evaluated by microbial culture method, scanning electron microscopy (SEM), and qPCR for quantification of Streptococcus oralis, Actinomyces naeslundii, Fusobacterium nucleatum, as well as total bacteria. For the in vitro study, adhesion tests were performed with the species S. oralis and A. naeslundii for 24 h. Data were compared by ANOVA, with Tukey's post-test. Regarding the in vivo study, both the total aerobic and total anaerobic bacteria counts were similar among groups (p > 0.05). In qPCR, there was no difference among groups of bacteria adhered to the disks (p > 0.05), except for A. naeslundii, which was found in lower proportions in the Ti-Nano group (p < 0.05). In the SEM analysis, the groups had a similar bacterial distribution, with a predominance of cocci and few bacilli. In the in vitro study, there was no difference in the adhesion profile for S. oralis and A. naeslundii after 24 h of biofilm formation (p > 0.05). Thus, we conclude that micro- and nanotopography do not affect bacterial adhesion, considering an initial period of biofilm formation.

Nanotopography and oral bacterial adhesion on titanium surfaces: in vitro and in vivo studies

Abstract The present study aimed to evaluate the influence of titanium surface nanotopography on the initial bacterial adhesion process by in vivo and in vitro study models. Titanium disks were produced and characterized according to their surface topography: machined (Ti-M), microtopography (Ti-Micro), and nanotopography (Ti-Nano). For the in vivo study, 18 subjects wore oral acrylic splints containing 2 disks from each group for 24 h (n = 36). After this period, the disks were removed from the splints and evaluated by microbial culture method, scanning electron microscopy (SEM), and qPCR for quantification of Streptococcus oralis, Actinomyces naeslundii, Fusobacterium nucleatum, as well as total bacteria. For the in vitro study, adhesion tests were performed with the species S. oralis and A. naeslundii for 24 h. Data were compared by ANOVA, with Tukey's post-test. Regarding the in vivo study, both the total aerobic and total anaerobic bacteria counts were similar among groups (p > 0.05). In qPCR, there was no difference among groups of bacteria adhered to the disks (p > 0.05), except for A. naeslundii, which was found in lower proportions in the Ti-Nano group (p < 0.05). In the SEM analysis, the groups had a similar bacterial distribution, with a predominance of cocci and few bacilli. In the in vitro study, there was no difference in the adhesion profile for S. oralis and A. naeslundii after 24 h of biofilm formation (p > 0.05). Thus, we conclude that micro- and nanotopography do not affect bacterial adhesion, considering an initial period of biofilm formation.

Culturable microbiological profile of a non-sterile drugs pharmaceutical production environment

Abstract For places where non-sterile drug production occurs, regulatory bodies recommend monitoring of the environmental bioburden. This procedure provides information regarding possible microbiological risks to which the products may be exposed, so that subsequent action measures may be implemented. The aim of the present work was to quantify and characterize the microorganisms present in Grade D (ISO 8) cleanrooms of a Brazilian pharmaceutical industry, identifying any possible seasonal climatic influences on these environments. Sampling was performed by surface and air monitoring, over 12 months during the year 2019, in rooms that were in operation. For both sampling methods, no statistically significant differences in bacteria and fungi counts were found between months or seasonal periods. Microorganisms that presented higher incidence included Staphylococcus epidermidis (15%) and Micrococcus spp. (13%), common to the human microbiota, and the fungi Cladosporium sp. (23%) and Penicillium sp. (21%), typical of the external environment. The results showed that microbial contamination in the Grade D cleanrooms was within the permissible maximum levels and remained similar throughout the year. Microbiological quality control in the clean areas of the pharmaceutical industry investigated was considered effective, with regular maintenance being necessary to keep bioburden levels controlled.

Mechanical and antibacterial properties of an experimental flowable composite containing Nb2O5 and NF_TiO2 nanoparticles.

This study developed an experimental flowable composite incorporated with niobium pentoxide (Nb2O5) combined or not with titanium dioxide co-doped with fluorine and nitrogen (NF_TiO2) and evaluated the mechanical and antibacterial properties. The experimental flowable composite (TEGDMA + BisGMA 1:1 + 60%wt - inorganic filler - borosilicate 0.7 µm) was formulated according to the type and concentration of Nb2O5 and NF_TiO2 (0.5, 1, 1.5 and 2 wt%) or NF_TiO2 + Nb2O5 (0.25, 0.5, 0.75 and 1 wt% - 1:1). The control groups were formed by the experimental composite without the incorporation of Nb2O5 and/or NF_TiO2 (GC-E) and by a commercial flowable composite (GC). The characterization of the surface of the composite and its particles was carried out using scanning electron microscopy (SEM) and energy dispersive x-rays (EDX). Specimens were manufactured and subjected to mechanical tests of flexural strength (FS) (n = 12), flexural modulus (FM) (n = 12), roughness (Ra) (n = 10), microhardness (n = 10), and contact angle (n = 10); and, to evaluate the antibacterial activity, they were submitted to tests of biofilm formation against S. mutans (CFU/mL) (n = 5), biofilm biomass by dry weight (n = 5) and confocal laser microscopy (%LIVE/DEAD) (n = 5). Data were submitted to one-way ANOVA and Tukey's post-hoc and, those that were not homoscedastic, but with normality, were submitted to Welch's ANOVA and Games-Howell's post-hoc. Dunnet's test was used to compare the controls with the other experimental groups (α = 5). The Nb2O5 particles had an average size of 32.4 µm and the nanoparticles (NPs) of NF_TiO2, 10 nm. EDX analysis identified isolated peaks of N, F, Ti, and Nb confirming the presence of these particles in the resin matrix. The 1.5% NF_TiO2 group had a higher FS and FM than the controls (p < 0.05). GC showed higher microhardness between groups (p < 0.05). There was no difference between the experimental groups regarding contact angle and roughness (p > 0.05), except for GC, which had the highest Ra values and the lowest contact angle between groups (p < 0.05). Composites containing 0.5%, 1%, 1.5%, and 2% Nb2O5, 1%, 1.5%, and 2% NF_TiO2 and 2% Nb2O5 + NF_TiO2 showed lower biofilm formation (p < 0.05), lower total biofilm biomass (p < 0.05), and a higher percentage of dead cells (44%, 52%, 52%, 79%, 42% 43%, 62%, 65%, respectively) than GC and GC-E (5% and 1%, respectively). It is concluded that the incorporation of 1.5% NF_TiO2 promoted a greater FS and FM among the experimental composites and that the addition of Nb2O5 particles (0.5%, 1%, 1.5%, and 2%), NF_TiO2 (1%, 1.5% and 2%) and the combination Nb2O5 + NF_TiO2 (2%) showed significant antibacterial effects.

The Self-assembling peptide P11-4 influences viability and osteogenic differentiation of stem cells of the apical papilla (SCAP).

OBJECTIVE: To analyze the effect of P11-4 self-assembly peptide on cell viability and osteogenic capacity of SCAPs through mineral deposition and gene expression of osteogenic markers. METHODS: SCAPs were seeded in contact with P11-4 (10 µg/ml, 100 µg/ml and 1 mg/ml) solution. Cell viability was evaluated using a colorimetric assay MTT: 3-(4,5-dimethyl-thiazolyl-2)-2,5- diphenyltetrazolium bromide) in an experimental time of 24, 48 and 72 h (n = 7). Mineral deposition and quantification provided by the cells was tested using the Alizarin Red staining and Cetylpyridinium Chloride (CPC), respectively, after 30 days (n = 4). Gene expression of Runt-related transcription factor 2 (RUNX2), Alkaline phosphatase (ALP) and Osteocalcin (OCN) was quantified using quantitative polymerase chain reaction (RT-qPCR), at 3 and 7 days with Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) as the housekeeping gene, and relative gene expression was measured using the ΔΔCq method. Data were analyzed using Kruskall-Wallis followed by multiple comparisons, and T-test for gene expression with α=0.05. RESULTS: All tested concentrations (10 µg/ml, 100 µg/ml and 1 mg/ml) were not cytotoxic at time 24 and 48 h. After 72 h, a slight decrease in cell viability was observed for the lowest concentration (10 µg/ml). The concentration of 100 µg/ml P11-4 showed the highest mineral deposition. However, qPCR analysis of P11-4 (10 µg/ml) showed upregulation of RUNX2 and OCN at 3 days, with downregulation of ALP at 3 and 7d CONCLUSION: P11-4 did not affect cell viability, induced mineral deposition in SCAPs, and upregulated the expression of RUNX2 and OCN genes at 3 days, while downregulating ALP expression at 3 and 7 days. CLINICAL SIGNIFICANCE: Based on the results obtained in this study it can be stated that self-assembling peptide P11-4 is a potential candidate to induce mineralization on dental stem cells for regenerative purposes and also for a clinical use as a capping agent without compromising the cells health.

Supramolecular Arrangement of Doxycycline with Sulfobutylether-ß-Cyclodextrin: Impact on Nanostructuration with Chitosan, Drug Degradation and Antimicrobial Potency.

Doxycycline (DX) is a well-established and broad-spectrum antimicrobial drug. However, DX has drawbacks, such as physicochemical instability in aqueous media and bacterial resistance. The inclusion of drugs in cyclodextrin complexes and their loading into nanocarriers can overcome these limitations. Thus, we studied the DX/sulfobutylether-ß-CD (SBE-ß-CD) inclusion complex for the first time and used it to reticulate chitosan. The resulting particles were evaluated by their physicochemical characteristics and antibacterial activity. DX/SBE-ß-CD complexes were characterized by nuclear magnetic resonance, infrared spectroscopy, thermal analysis, X-ray diffraction, and scanning electron microscopy (SEM), whereas DX-loaded nanoparticles were characterized by dynamic light scattering, SEM, and drug content. The partial inclusion of the DX molecule in CD happened in a 1:1 proportion and brought increased stability to solid DX upon thermal degradation. Chitosan-complex nanoparticles measured approximately 200 nm, with a narrow polydispersity and particles with sufficient drug encapsulation for microbiological studies. Both formulations preserved the antimicrobial activity of DX against Staphylococcus aureus, whereas DX/SBE-ß-CD inclusion complexes were also active against Klebsiella pneumoniae, indicating the potential use of these formulations as drug delivery systems to treat local infections.

Development, characterization and antimicrobial activity of multilayer silica nanoparticles with chlorhexidine incorporated into dental composites.

OBJECTIVE: In this study a dentistry nanocomposite with prolonged antibacterial activity using silica nanoparticles (SNPs) loaded with chlorhexidine (CHX) was developed. METHODS: SNPs were coated with the Layer-by-Layer technique. Dental composites were prepared with organic matrix of BisGMA/TEGDMA and SNPs with or without CHX (0, 10, 20 or 30% w/w). The physicochemical properties of the developed material were evaluated and agar diffusion method was used to test the antibacterial. In addition, the biofilm inhibitory activity of the composites was evaluated against S. mutans. RESULTS: SNPs were rounded with diameters about 50 nm, the organic load increased with increasing deposited layers. Material samples with SNPs loaded with CHX (CHX-SNPs) showed the highest values of post-gel volumetric shrinkage, that ranged from 0.3% to 0.81%. Samples containing CHX-SNPs 30% w/w showed the highest values of flexural strength and modulus of elasticity. Only samples containing SNPs-CHX showed growth inhibition against S. mutans, S. mitis and S. gordonii in a concentration-dependent manner. The composites with CHX-SNPs reduced the biofilm formation of S. mutans biofilm at 24 h and 72 h. SIGNIFICANCE: The nanoparticle studied acted as fillers and did not interfere with the evaluated physicochemical properties while providing antimicrobial activity against streptococci. Therefore, this initial study is a step forward to the synthesis of experimental composites with improved performance using CHX-SNPs.

Statins and oral biofilm: Simvastatin as a promising drug to control periodontal dysbiosis.

OBJECTIVES: This study evaluated antimicrobial activity of atorvastatin, pravastatin, rosuvastatin, and simvastatin against oral bacteria, and the interaction of simvastatin with standard antimicrobials (amoxicillin and metronidazole). METHODS: Minimal inhibitory concentration assays were performed with Porphyromonas gingivalis, Prevotella intermedia, Fusobacterium nucleatum, Actinomyces odontolyticus, Streptococcus oralis, Streptococcus mitis, Streptococcus salivarius, Streptococcus sanguinis, and Streptococcus gordonii; checkerboard microdilution assays between simvastatin and standard antimicrobials; monospecies and multispecies biofilms. RESULTS: Simvastatin showed the best antimicrobial activity against most species (MIC range from 3.12 to 25 µg/ml), highlighting the sensitivity of P. gingivalis. In the checkerboard assay, synergistic interaction was found between simvastatin and amoxicillin against S. oralis and S. sanguinis. P. gingivalis biofilm was inhibited by simvastatin at 10 and 50× Minimal inhibitory concentration, with similar effects to metronidazole. For multispecies biofilm, SMV reduced the biofilm metabolic activity (79%) and total counts (87%), comparable to amoxicillin. Simvastatin also reduced bacterial counts of Veilonnella parvula, P. gingivalis, Streptococcus mutans, Actinomyces naeslundii, P. intermedia, and Capnocytophaga ochracea in the multispecies biofilm. CONCLUSIONS: Simvastatin showed antimicrobial and antibiofilm activity against oral bacteria and may contribute to the control of dysbiosis, and may be considered in clinical studies as an adjuvant in the treatment of periodontitis.

IL10 promoter rs6667202 polymorphism is functional in health but not in grade c periodontitis patients: A pilot study.

BACKGROUND AND OBJECTIVE: Previous studies have demonstrated an association between the IL10 promoter rs6667202 (C > A) single-nucleotide polymorphism (SNP) and grade C, stage 3 or 4 periodontitis (Perio4C) in the Brazilian population, where the altered A allele was detected more frequently in these patients. However, no functional analysis of this variation has yet been performed. Thus, the objective of this preliminary study was to evaluate the functionality of rs6667202 in gingival fibroblasts (GFs) of individuals with Perio4C and with periodontal health (PH) stimulated with Aggregatibacter actinomycetencomitans protein extract (AaPE). METHODS: Patients with PH and Perio4C were segregated according to their genotype (AA, AC, or CC), and a biopsy was performed to establish the culture of the GFs. After GFs exposure to AaPE at 5 µg/ml for 1.5 h, RNA was extracted to analyze IL10 expression by qPCR. Aliquots of the cell's supernatant were subjected to immunoenzymatic analysis (MAGpix) to detect interleukin-10 (IL-10). RESULTS: In PH, the genotypes AA and AC are related to less expression of IL10 (p = 0.027 and p < 0.0001) and less production of IL-10 (p = 0.002 and p = 0.001), when compared to CC. In Perio4C, there was no statistical difference between the genotypes (p > 0.05), although a lower IL-10 expression and release compared with PH CC was seen (p = 0.033 and p < 0.001). CONCLUSION: The rs6667202 SNP is functional in PH, as it decreases the expression and production of IL-10. In Perio4C, other factors may be masking its action by altering the IL-10's response.

Statins with potential to control periodontitis: From biological mechanisms to clinical studies.

BACKGROUND: Statins are widely used for the treatment of hyperlipidemia. However, these drugs have pleiotropic effects that can be promising for the prevention and treatment of oral diseases, such as periodontitis. HIGHLIGHT: This review aimed to identify preclinical, observational, and clinical studies that evaluate the effects and biological mechanisms of statins on oral cells and tissues and those using these drugs to treat periodontitis. A literature survey has been conducted in PubMed using combinations of the uniterms: "statins," "dentistry," "periodontal disease," and "periodontal treatment." In vitro findings showed positive statin results in cell lines related to alveolar bone metabolism by altering the signaling pathway Osteoprotegerin/Receptor Activator of Nuclear Factor Kappa B/Receptor Activator of Nuclear Factor Kappa B Ligand (OPG/RANK/RANKL), stimulating the production of alkaline phosphatase and osteocalcin, and reducing the production of matrix metalloproteinases (MMPs). Animal studies have shown a reduction in alveolar bone loss and osteoclastic activity, in addition to a reduction in inflammatory markers, such as IL-1, IL-6, and TNF-α, when statins were used prophylactically. Clinical trials showed a positive impact on clinical parameters, leading to a higher reduction in probing depth and gain in clinical attachment when a local statin was adjunctively associated with mechanical therapy. CONCLUSION: Statins were shown to be promising for regenerating and stimulating bone activity, with great potential for treating chronic periodontitis. However, further studies are required to confirm its effectiveness.

Skin microbiota as a therapeutic target for psoriasis treatment: Trends and perspectives.

Psoriasis is a chronic, immune-mediated disease that has a major negative impact on a patient's quality of life. Although several literature reviews indicate that skin microbiota may play an important role in the development and regulation of the immune and inflammatory response of psoriasis, few clinical studies are demonstrating the benefits of using pre-, pro- and synbiotics as a therapeutic alternative at the management of the disease. In this review, we showed the use of probiotic microorganisms that may contribute to skin homeostasis and compiled the clinical trials that demonstrate the effect of therapy with probiotics on patients with psoriasis, an important area for scientific exploration in dermatology and being the first review article to compile this information.

Máscaras caseiras na pandemia de COVID-19: recomendações, características físicas, desinfecção e eficácia de uso / Mascarillas caseras en la pandemia de COVID-19: recomendaciones, características físicas, desinfección y eficacia de uso / Homemade masks in the COVID-19 pandemic: recommendations, physical characteristics, disinfection and efficacy

Objetivo: Descrever as recomendações, características físicas, métodos de desinfecção e eficácia de uso de máscaras caseiras na redução da transmissão da COVID-19. Métodos: Realizou-se busca nas bases de dados MEDLINE, SciELO e Google Scholar, além das recomendações oficiais de uso. Resultados: Foram incluídas 31 referências. A capacidade de filtração de tecidos variou entre 5% e 98%. Tecidos 100% algodão em duas ou três camadas apresentaram eficácia de filtração entre 70% e 99% em estudos in vitro. Máscaras caseiras, cirúrgicas e respiradores apresentaram respirabilidade entre 2,2 e 3,0 Pascal. A capacidade de redução da propagação de microrganismos por pessoas usando máscaras caseiras foi três vezes menor do que usando máscaras cirúrgicas, embora tenha sido superior ao não uso de máscaras. Conclusão: A respirabilidade de máscaras caseiras mostrou-se adequada, enquanto a capacidade de filtração parece ser inferior à das máscaras cirúrgicas, mas superior a não se usar máscara. Não há evidências que respaldem a eficácia e efetividade das máscaras caseiras.

Objetivo: Describir las recomendaciones, características físicas, métodos de desinfección y efectividad de mascarillas caseras para reducir la transmisión de COVID-19. Métodos: La búsqueda se realizó en las bases de datos MEDLINE, SciELO y Google Scholar, además de las recomendaciones oficiales de uso. Resultados: Se incluyeron 31 referencias. La capacidad de filtración de los tejidos varió entre 5% y 98%. Los tejidos al 100% de algodón, en dos o tres capas, mostraron eficiencia de filtración entre 70% y 99%, en estudios in vitro. Mascarillas caseras, quirúrgicas y de respiradores mostraron respirabilidad entre 2,2 y 3,0 Pascal. La capacidad de reducir la propagación de microorganismos por personas que usan máscarillas caseras fue tres veces menor que cuando usaban mascarillas quirúrgicas, pero superior a no usarlas. Conclusión: La respirabilidad de las mascarillas caseras puede ser adecuada, mientras que la eficiencia de filtración parece ser inferior a la de las mascarillas quirúrgicas, pero superior a no utilizar mascarilla. No hay evidencia que respalde su eficacia y efectividad.

Objective: To describe the recommendations, physical characteristics, disinfection methods and efficacy of the use of homemade face masks to reduce COVID-19 transmission. Methods: We searched MEDLINE, SciELO, and Google Scholar, in addition to the official recommendations for the use of masks. Results: Thirty-one references were included. Fabric filtration efficiency ranged from 5% to 98%. The filtration efficacy of three layered 100% cotton fabric face masks ranged from 70% and 99% in vitro studies. Homemade, surgical, and respirator masks showed breathability between 2.2 and 3.0 Pascal. The capacity to reduce the spread of microorganisms by people wearing homemade face masks was three times lower when compared to those wearing surgical masks, although this capacity was higher when compared to those who did not wear masks. Conclusion: The breathability of homemade masks proved to be adequate, while the filtration ability seemed to be lower than that of surgical masks, but it was better than not wearing any masks at all. There is no evidence to support the efficacy and effectiveness of homemade masks.

Fusogenic Liposomes Increase the Antimicrobial Activity of Vancomycin Against Staphylococcus aureus Biofilm.

Objective: The aim of the present study was to encapsulate vancomycin in different liposomal formulations and compare the in vitro antimicrobial activity against Staphylococcus aureus biofilms. Methods: Large unilamellar vesicles of conventional (LUV VAN), fusogenic (LUVfuso VAN), and cationic (LUVcat VAN) liposomes encapsulating VAN were characterized in terms of size, polydispersity index, zeta potential, morphology, encapsulation efficiency (%EE) and in vitro release kinetics. The formulations were tested for their Minimum Inhibitory Concentration (MIC) and inhibitory activity on biofilm formation and viability, using methicillin-susceptible S. aureus ATCC 29213 and methicillin-resistant S. aureus ATCC 43300 strains. Key Findings: LUV VAN showed better %EE (32.5%) and sustained release than LUVfuso VAN, LUVcat VAN, and free VAN. The formulations were stable over 180 days at 4°C, except for LUV VAN, which was stable up to 120 days. The MIC values for liposomal formulations and free VAN ranged from 0.78 to 1.56 µg/ml against both tested strains, with no difference in the inhibition of biofilm formation as compared to free VAN. However, when treating mature biofilm, encapsulated LUVfuso VAN increased the antimicrobial efficacy as compared to the other liposomal formulations and to free VAN, demonstrating a better ability to penetrate the biofilm. Conclusion: Vancomycin encapsulated in fusogenic liposomes demonstrated enhanced antimicrobial activity against mature S. aureus biofilms.

New pharmacological insights of Galactia glaucescens.

Galactia glaucescens leaves are popularly used against snakebites in Brazil. The hydroethanolic extract from aerial parts of G. glaucescens (HEGg) was assayed against the neurotoxicity and myotoxicity induced by Bothrops jararacussu venom. A traditional myographic technique was applied for neurotoxicity and the resulting muscles were treated routinely by light microscopy analysis for myotoxicity. Additionally, the antimicrobial potential of HEGg was evaluated against Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa strains, as well as Rutin was isolated for the first time in this specie using chromatographic and spectroscopic methods and its antiophidian property was assessed. HEGg totally prevents the neurotoxicity and myotoxicity effects caused by B. jararacussu, but did not show any antimicrobial effect. Concluding, HEGg and Rutin were able to counteract the toxic effects of the venom and confirmed the antiophidian potential, but not antimicrobial, of G. glaucescens as an alternative for neutralization of B. jararacussu venom.

Stress-related salivary proteins affect the production of volatile sulfur compounds by oral bacteria.

OBJECTIVE: To determine whether stress-related substances and sex hormones influence the growth and in vitro production of volatile sulfur compounds (VSCs) by Solobacterium moorei and Fusobacterium nucleatum. MATERIALS AND METHODS: Bacteria growth and VSCs production were evaluated in the presence of alpha-amylase, beta-defensin-2, mucin, estradiol, and progesterone. Growth was evaluated by colony counting, and the production of the VSCs hydrogen sulfide (H2 S) and methyl mercaptan (CH3 SH) was measured using the Oral Chroma™ instrument. RESULTS: Mucin induced the production of H2 S by both bacteria, but had a slight inhibitory effect on CH3 SH production by F. nucleatum. It also increased the viability of F. nucleatum. Alpha-amylase increased H2 S production by S. moorei and CH3 SH production by F. nucleatum, but had no effect on H2 S production by F. nucleatum. No substance altered the viability of S. moorei. No effects of beta-defensin-2, estradiol, or progesterone were observed. CONCLUSION: The salivary stress-related proteins mucin and alpha-amylase altered VSCs production by F. nucleatum and S. moorei, favoring H2 S production. These findings are a step toward understanding the relation between stress and increased amounts of H2 S.

Effects of chlorhexidine preprocedural rinse on bacteremia in periodontal patients: a randomized clinical trial.

OBJECTIVE: Single dose of systemic antibiotics and short-term use of mouthwashes reduce bacteremia. However, the effects of a single dose of preprocedural rinse are still controversial. This study evaluated, in periodontally diseased patients, the effects of a pre-procedural mouth rinse on induced bacteremia. MATERIAL AND METHODS: Systemically healthy individuals with gingivitis (n=27) or periodontitis (n = 27) were randomly allocated through a sealed envelope system to: 0.12% chlorhexidine pre-procedural rinse (13 gingivitis and 13 periodontitis patients) or no rinse before dental scaling (14 gingivitis and 15 periodontitis patients). Periodontal probing depth, clinical attachment level, plaque, and gingival indices were measured and subgingival samples were collected. Blood samples were collected before dental scaling, 2 and 6 minutes after scaling. Total bacterial load and levels of P. gingivalis were determined in oral and blood samples by real-time polymerase chain reaction, while aerobic and anaerobic counts were determined by culture in blood samples. The primary outcome was the antimicrobial effect of the pre-procedural rinse. Data was compared by Mann-Whitney and Signal tests (p<0.05). RESULTS: In all sampling times, polymerase chain reaction revealed higher blood bacterial levels than culture (p<0.0001), while gingivitis patients presented lower bacterial levels in blood than periodontitis patients (p<0.0001). Individuals who experienced bacteremia showed worse mean clinical attachment level (3.4 mm vs. 1.1 mm) and more subgingival bacteria (p<0.005). The pre-procedural rinse did not reduce induced bacteremia. CONCLUSIONS: Bacteremia was influenced by periodontal parameters. In periodontally diseased patients, pre-procedural rinsing showed a discrete effect on bacteremia control.

Effects of chlorhexidine preprocedural rinse on bacteremia in periodontal patients: a randomized clinical trial

Abstract Objective: Single dose of systemic antibiotics and short-term use of mouthwashes reduce bacteremia. However, the effects of a single dose of preprocedural rinse are still controversial. This study evaluated, in periodontally diseased patients, the effects of a pre-procedural mouth rinse on induced bacteremia. Material and Methods: Systemically healthy individuals with gingivitis (n=27) or periodontitis (n = 27) were randomly allocated through a sealed envelope system to: 0.12% chlorhexidine pre-procedural rinse (13 gingivitis and 13 periodontitis patients) or no rinse before dental scaling (14 gingivitis and 15 periodontitis patients). Periodontal probing depth, clinical attachment level, plaque, and gingival indices were measured and subgingival samples were collected. Blood samples were collected before dental scaling, 2 and 6 minutes after scaling. Total bacterial load and levels of P. gingivalis were determined in oral and blood samples by real-time polymerase chain reaction, while aerobic and anaerobic counts were determined by culture in blood samples. The primary outcome was the antimicrobial effect of the pre-procedural rinse. Data was compared by Mann-Whitney and Signal tests (p<0.05). Results: In all sampling times, polymerase chain reaction revealed higher blood bacterial levels than culture (p<0.0001), while gingivitis patients presented lower bacterial levels in blood than periodontitis patients (p<0.0001). Individuals who experienced bacteremia showed worse mean clinical attachment level (3.4 mm vs. 1.1 mm) and more subgingival bacteria (p<0.005). The pre-procedural rinse did not reduce induced bacteremia. Conclusions: Bacteremia was influenced by periodontal parameters. In periodontally diseased patients, pre-procedural rinsing showed a discrete effect on bacteremia control.

Pharmacological Properties of Vochysia Haenkeana (Vochysiaceae) Extract to Neutralize the Neuromuscular Blockade Induced by Bothropstoxin-I (Lys49 Phospholipase A2) Myotoxin.

Purpose: Bothrops snakes are responsible for more than 70 % of snakebites every year in Brazil and their venoms cause severe local and systemic damages. The pharmacological properties of medicinal plants have been widely investigated in order to discover new alternative treatments for different classes of diseases including neglected tropical diseases as envenomation by snakebites. In this work, we have investigated the ability of Vochysia haenkeana stem barks extract (VhE) to neutralize the neuromuscular effects caused by Bothropstoxin-I (BthTX-I), the major phospholipase A2 (PLA2) myotoxin from B. jararacussu venom. Methods: The biological compounds of VhE were analysed under thin layer chromatography (TLC) and its neutralizing ability against BthTX-I was assessed through twitch-tension recordings and histological analysis in mouse phrenic nerve-diaphragm (PND) preparations. The antimicrobial activity of VhE was assessed against S. aureus, E. coli and P. aeruginosa strains. The aggregation activity of VhE was analysed under protein precipitation assay. Results: VhE showed the presence of phenolic compound visualized by blue trace under TLC. VhE abolished the neuromuscular blockade caused by BthTX-I applying the pre-toxin incubation treatment and partially neutralized the BthTX-I action under post-toxin incubation treatment; VhE contributed slightly to decrease the myotoxicity induced by BthTX-I. The neutralizing mechanism of VhE may be related to protein aggregation. VhE showed no antimicrobial activity. Conclusion: V. haenkeana extract which has no antimicrobial activity exhibited neutralizing ability against the neuromuscular blockade caused by BthTX-I and also contributed to decrease its myotoxicity. Protein aggregation involving phenolic compounds may be related in these protective effects.

Silver nanoparticles in dentistry.

OBJECTIVE: Silver nanoparticles (AgNPs) have been extensively studied for their antimicrobial properties, which provide an extensive applicability in dentistry. Because of this increasing interest in AgNPs, the objective of this paper was to review their use in nanocomposites; implant coatings; pre-formulation with antimicrobial activity against cariogenic pathogens, periodontal biofilm, fungal pathogens and endodontic bacteria; and other applications such as treatment of oral cancer and local anesthesia. Recent achievements in the study of the mechanism of action and the most important toxicological aspects are also presented. METHODS: Systematic searches were carried out in Web of Science (ISI), Google, PubMed, SciFinder and EspaceNet databases with the keywords "silver nano* or AgNP*" and "dentist* or dental* or odontol*". RESULTS: A total of 155 peer-reviewed articles were reviewed. Most of them were published in the period of 2012-2017, demonstrating that this topic currently represents an important trend in dentistry research. In vitro studies reveal the excellent antimicrobial activity of AgNPs when associated with dental materials such as nanocomposites, acrylic resins, resin co-monomers, adhesives, intracanal medication, and implant coatings. Moreover, AgNPs were demonstrated to be interesting tools in the treatment of oral cancers due to their antitumor properties. SIGNIFICANCE: The literature indicates that AgNPs are a promising system with important features such as antimicrobial, anti-inflammatory and antitumor activity, and a potential carrier in sustained drug delivery. However, there are some aspects of the mechanisms of action of AgNPs, and some important toxicological aspects arising from the use of this system that must be completely elucidated.

Changes in salivary microbiota increase volatile sulfur compounds production in healthy male subjects with academic-related chronic stress.

OBJECTIVE: To investigate the associations among salivary bacteria, oral emanations of volatile sulfur compounds, and academic-related chronic stress in healthy male subjects. MATERIALS AND METHODS: Seventy-eight healthy male undergraduate dental students were classified as stressed or not by evaluation of burnout, a syndrome attributed to academic-related chronic stress. This evaluation was carried out using the Maslach Burnout Inventory-Student Survey questionnaire. Oral emanations of hydrogen sulfide, methyl mercaptan, and dimethyl sulfide were measured using an Oral Chroma™ portable gas chromatograph. The amounts in saliva of total bacteria and seven bacteria associated with halitosis were quantified by qPCR. The in vitro production of H2S by S. moorei and/or F. nucleatum was also measured with the Oral Chroma™ instrument. RESULTS: The stressed students group showed increased oral emanations of hydrogen sulfide and dimethyl sulfide, together with higher salivary Solobacterium moorei levels (p < 0.05, Mann Whitney test). There were moderate positive correlations between the following pairs of variables: Fusobacterium nucleatum and S. moorei; F. nucleatum and hydrogen sulfide; Tannerella forsythia and F. nucleatum; T. forsythia and S. moorei. These correlations only occurred for the stressed group (p < 0.05, Spearman correlation). The in vitro experiment demonstrated that S. moorei increased H2S production by F. nucleatum (p < 0.05, ANOVA and Tukey's test). CONCLUSION: The increased amount of S. moorei in saliva, and its coexistence with F. nucleatum and T. forsythia, seemed to be responsible for increased oral hydrogen sulfide in the healthy male stressed subjects.