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1.
Biofouling ; : 1-9, 2021 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-34708675

RESUMO

Polymicrobial biofilms comprising Candida albicans and Staphylococcus aureus can increase the frequency and severity of oral diseases. This study assessed oral keratinocyte cell death, apoptosis and/or necrosis, promoted by soluble factors from single and dual biofilms of S. aureus and C. albicans. The soluble factors were obtained from the 16-h biofilm growth media. Cell viability was assessed by MTT and cell membrane damage by LDH. SEM was used for morphology changes. Assessment of apoptosis and necrosis was performed using annexin V and propidium iodide and caspases -2, -3, -6, -8 and -9. Statistical analysis was conducted with ANOVA and Tukey tests (α = 5%). Dual biofilms promoted the greatest harmful effect on oral cells, with a viability rate of 31.76%, damage to cell membranes and LDH released. Dual biofilms also induced higher percentages of necrotic cells (24.95%). Apoptosis was associated with caspases -2, -3, -6 and -8 activation.

2.
Front Cell Infect Microbiol ; 11: 627043, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33718274

RESUMO

This study was aimed at analyzing proto-oncogenic signaling pathway activation in normal oral keratinocytes (NOK-si) and neoplastic cell lines (SCC 25 and Detroit 562) stimulated with metabolites (soluble factors) from single and dual biofilms of Candida albicans and Staphylococcus aureus. Soluble factors (SF) from early (16-h) and mature (36-h) biofilms of C. albicans and S. aureus were collected and incubated with cell cultures, which were subsequently evaluated using gene expression via RT-qPCR, cell viability via AlamarBlueTM, and flow cytometry cell cycle analysis. In general, exposure to the SF of early and mature biofilms from C. albicans and dual species caused a major reduction in NOK-si cell viability and enhanced the sub G0 phase. This led to a decrease in gene expression. However, in this cell line, SF of S. aureus biofilms upregulated the CDKN1A gene followed by the maintenance of cell viability and a significant increase in the G2/M population. For tumor cells, SCC 25 and Detroit 562, the stimuli of SF biofilms upregulated oncogenes such as hRAS and mTOR, as well as Bcl-2 and CDKN1A. SCC 25 and Detroit 562 cells could survive even after 24 h of stimuli from both SF (early and mature). This occurred without significant changes taking place in the cell cycle progression for SCC 25, and with a significant tendency to increase the G2/M phase for Detroit 562. These results point to the fact that metabolites from prevalent clinical fungal and bacterial biofilms, C. albicans and S. aureus, can disrupt the homeostasis of normal and neoplastic oral epithelial cells. This changes proto-oncogenes' expression, specifically PI3KCA, hRAS, mTOR, BRAF, and cell cycle genes CDKN1A and Bcl-2, thus causing a disturbance in cell viability, survival, and the cell cycle profile.


Assuntos
Candida albicans , Staphylococcus aureus , Biofilmes , Candida albicans/genética , Células Epiteliais , Genes cdc , Proto-Oncogenes , Staphylococcus aureus/genética
3.
Carbohydr Polym ; 257: 117604, 2021 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-33541637

RESUMO

This study demonstrated a drug-delivery system with anionic beta cyclodextrin (ß-CD) complexes to retain tetracycline (TC) and control its release from multilayers of poly(acrylic acid) (PAA) and poly(l-lysine) (PLL) in a ten double layers ([PAA/PLL]10) coating onto titanium. The drug-delivery capacity of the multilayer system was proven by controlled drug release over 15 days and sustained released over 30 days. Qualitative images confirmed TC retention within the layer-by-layer (LbL) over 30 days of incubation. Antibacterial activity of TC/anionic ß-CD released from the LbL was established against Staphylococcus aureus species. Remarkably, [PAA/PLL]10/TC/anionic ß-CD antibacterial effect was sustained even after 30 days of incubation. The non-cytotoxic effect of the multilayer system revealed normal human gingival fibroblast growth. It is expected that this novel approach and the chemical concept to improve drug incorporation into the multilayer system will open up possibilities to make the drug release system more applicable to implantable percutaneous devices.


Assuntos
Materiais Revestidos Biocompatíveis/química , Preparações de Ação Retardada/química , Sistemas de Liberação de Medicamentos , Staphylococcus aureus/efeitos dos fármacos , beta-Ciclodextrinas/química , Resinas Acrílicas/química , Ânions , Antibacterianos/administração & dosagem , Quitosana/química , Liberação Controlada de Fármacos , Fibroblastos/efeitos dos fármacos , Humanos , Concentração de Íons de Hidrogênio , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Polímeros/química , Próteses e Implantes , Desenho de Prótese , Propriedades de Superfície , Tetraciclina/química , Titânio/química
4.
Inorg Chem ; 60(2): 1062-1079, 2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33372756

RESUMO

Silver tungstate (Ag2WO4) shows structural polymorphism with different crystalline phases, namely, orthorhombic, hexagonal, and cubic structures that are commonly known as α, ß, and γ, respectively. In this work, these Ag2WO4 polymorphs were selectively and successfully synthesized through a simple precipitation route at ambient temperature. The polymorph-controlled synthesis was conducted by means of the volumetric ratios of the silver nitrate/tungstate sodium dehydrate precursors in solution. The structural and electronic properties of the as-synthesized Ag2WO4 polymorphs were investigated by using a combination of X-ray diffraction and Rietveld refinements, X-ray absorption spectroscopy, X-ray absorption near-edge structure spectroscopy, field-emission scanning electron microscopy images, and photoluminescence. To complement and rationalize the experimental results, first-principles calculations, at the density functional theory level, were carried out, leading to an unprecedented glimpse into the atomic-level properties of the morphology and the exposed surfaces of Ag2WO4 polymorphs. Following the analysis of the local coordination of Ag and W cations (clusters) at each exposed surface of the three polymorphs, the structure-property relationship between the morphology and the photocatalytic and antibacterial activities against amiloride degradation under ultraviolet light irradiation and methicillin-resistant Staphylococcus aureus, respectively, was investigated. A possible mechanism of the photocatalytic and antibacterial activity as well the formation process and growth of the polymorphs is also explored and proposed.


Assuntos
Antibacterianos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Óxidos/farmacologia , Prata/farmacologia , Tungstênio/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Catálise , Teoria da Densidade Funcional , Testes de Sensibilidade Microbiana , Modelos Moleculares , Óxidos/química , Tamanho da Partícula , Processos Fotoquímicos , Prata/química , Relação Estrutura-Atividade , Propriedades de Superfície , Tungstênio/química , Raios Ultravioleta
5.
Oral Health Prev Dent ; 18(1): 999-1010, 2020 11 20.
Artigo em Inglês | MEDLINE | ID: mdl-33215491

RESUMO

PURPOSE: This study investigated the effect of long-term daily chemical disinfection on the topographic and Candida albicans biofilm formation on a denture base resin and a reline acrylic resin. MATERIAL AND METHODS: Circular samples (14 × 1.2 mm) were fabricated from a denture base (Vipi Wave) and reline acrylic resins (Tokuyama Rebase Fast II). Samples were kept in 50 ml of distilled water (48 h at 37°C). Subsequently, the samples were immersed in five different solutions: 0.5% sodium hypochlorite; 3.8% sodium perborate; 2% chlorhexidine gluconate; apple vinegar containing 4% maleic acid; and distilled water (control group). The specimen was immersed in the solutions for 8 h daily and transferred to distilled water at 37°C for more 16 h. The surface topographic and Candida albicans (ATCC 90028) biofilm formation were evaluated at baseline (before chemical disinfection) and after 1, 3 and 6 months of immersion. The surface topographic was evaluated by arithmetical roughness average (Ra) and scanning electron microscope (SEM), while the biofilm formation was evaluated by colony-forming units (CFU/ml) method and Alamar Blue assay (cell metabolism). The results were evaluated by three-way analysis of variance (ANOVAs) and post-hoc tests (α = 0.05). RESULTS: The results showed statistically significant effects from the type of acrylic resin (p = 0.029) and time (p <0.001) on the roughness of the specimen. In general, the reline resin had higher roughness than the denture base resin. In addition, the roughness of the samples after 1, 3 and 6 months of immersion in the cleaning solutions was higher than at baseline. In relation to the microbiological assays, there were no statistically significant differences (p >0.055) in the CFU/ml values of the biofilms among the different resins, periods of time and cleaning solutions. Considering the metabolism of the cells within the biofilms, the results showed that, at baseline, it was statistically significantly higher (p <0.05) than after 1, 3 and 6 months of storage. The SEM images showed that all disinfectant solutions provided surface changes of both acrylic resins (base and reline) after 1, 3 and 6 months of immersion. CONCLUSIONS: The roughness of both acrylic resins was affected by the disinfection in all cleaning agents, increasing over time, and this effect was more evident in the reline acrylic resin group. This surface change was also observed in the SEM images. While the number of cells within the biofilms was not affected by immersion in the cleaning agents, their metabolism was lower after 1, 3 and 6 months of immersion.


Assuntos
Candida albicans , Desinfecção , Resinas Acrílicas , Biofilmes , Bases de Dentadura , Higienizadores de Dentadura/farmacologia , Teste de Materiais , Propriedades de Superfície
6.
Mater Sci Eng C Mater Biol Appl ; 111: 110765, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32279798

RESUMO

Crystal morphology with different surfaces is important for improving the antibacterial activity of materials. In this experimental and theoretical study, the antibacterial activity of ß-Ag2MoO4 microcrystals against the Gram-positive bacteria, namely, methicillin-resistant Staphylococcus aureus (MRSA), and the Gram-negative bacteria, namely, Escherichia coli (E. coli), was investigated. In this study, ß-Ag2MoO4 crystals with different morphologies were synthetized by a simple co-precipitation method using three different solvents. The antimicrobial efficacy of the obtained microcrystals against both bacteria increased according to the solvent used in the following order: water < ammonia < ethanol. Supported by experimental evidence, a correlation between morphology, surface energy, and antibacterial performance was established. By using the theoretical Wulff construction, which was obtained by means of density functional calculations, the morphologies with large exposition of the (001) surface exhibited superior antibacterial activity. This study provides a low cost route for synthesizing ß-Ag2MoO4 crystals and a guideline for enhancing the biological effect of biocides on pathogenic bacteria by the morphological modulation.


Assuntos
Antibacterianos/química , Molibdênio/química , Antibacterianos/farmacologia , Teoria da Densidade Funcional , Escherichia coli/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Solventes/química , Espectroscopia de Infravermelho com Transformada de Fourier
7.
Mater Sci Eng C Mater Biol Appl ; 108: 110405, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31923947

RESUMO

The number of studies on microcrystals containing silver has increased in recent decades. Among the silver-containing microcrystals, α-AgVO3 has gained prominence owing to its polymorphism that allows it to exert interesting antimicrobial activity against pathogenic microorganisms. The aim of this study was to evaluate the antifungal activity and cytotoxicity of three different α-AgVO3 microcrystals when in solution. α-AgVO3 microcrystals were synthesized using the co-precipitation method at three different temperatures (10 °C, 20 °C, and 30 °C), and then characterized by X-ray diffraction and scanning electron microscopy. The antifungal activity of α-AgVO3 microcrystals against Candida albicans was determined by estimating the minimum inhibitory concentration (MIC) and minimum fungicidal concentration (MFC). Fluorescence images were obtained to confirm antifungal concentrations. To assess the biocompatibility of microcrystals applied at MIC and MFC on keratinocytes cells (NOK-si), an Alamar Blue assay, scanning electron microscopy, and a DNA gel integrity test were carried out. The quantitative and qualitative results showed that, regardless of the co-precipitation method used to synthetize α-AgVO3 microcrystals, C. albicans growth was visibly inhibited at 3.9 µg/mL (MIC) and completely inhibited at 15.62 µg/mL (MFC). The cytotoxic and genotoxic outcomes revealed that the MIC and MFC concentrations did not affect NOK-si cell morphology, proliferation, or DNA integrity. The search for new antimicrobial materials has been the focus of the research community recently because of increases in microbial resistance. The findings reported herein demonstrate a novel antifungal and non-cytotoxic material that could be used in biomedical and dental applications.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Óxidos/farmacologia , Compostos de Prata/farmacologia , Compostos de Vanádio/farmacologia , Antifúngicos/efeitos adversos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Testes de Sensibilidade Microbiana , Microscopia de Fluorescência , Óxidos/efeitos adversos , Compostos de Prata/efeitos adversos , Compostos de Vanádio/efeitos adversos
8.
J Periodontol ; 90(5): 507-515, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30387879

RESUMO

BACKGROUND: Evaluate the effect of low-temperature plasma (LTP) on an anaerobic biofilm and on the biological response of an in vitro reconstituted gingival epithelium tissue. METHODS: Porphyromonas gingivalis W83 biofilm was cultured on titanium discs and reconstituted gingival tissues were submitted to similar treatment conditions. TREATMENTS: LTP1-plasma treatment for 1 minute, LTP3-plasma treatment for 3 minute, CHX-0.2% chlorhexidine for 1 minute, GAS-gas only (no plasma) for 3 minute, and NEGATIVE-no treatment. TRITON group was included as a positive control for tissue analysis. Counting of viable colony forming units (CFU/mL) and confocal laser scanning microscopy were performed to evaluate LTP's antimicrobial effect. EpiGingival tissue was evaluated through cytotoxocity, viability, histology, and imunnohistochemistry (Ki67, vascular endothelial growth factor-A vascular endothelial growth factor A [VEGF-A], and terminal deoxynucleotidyl transferase dUTP nick end labeling terminal deoxynucleotidyl transferase dutp nick end labeling [TUNEL] expression). RESULTS: LTP1 and LTP3 presented significantly different reduced CFU/mL reduction in comparison to the negative control (Ρ < 0.001), but it was not as effective as the positive control (CHX). Low cytotoxicity and high viability were observed in gingival epithelium of NEGATIVE, GAS, CHX, and both LTP groups. The morphologic analysis of gingival epithelium revealed minor cell damage in the plasma groups (score 1). LTP1, LTP3, GAS, and NEGATIVE groups exhibited less than 5% of basal layer positive cells. LTP1, LTP3, GAS, and CHX groups were not positive for TUNEL assay. LTP1 and LTP3 showed the most positivity for VEGF. CONCLUSIONS: LTP treatment can be considered as an effective method for reducing P. gingivalis biofilm on implant surfaces, while being safe for the gingival epithelium. Furthermore, plasma treatment may be associated with cell repair.


Assuntos
Biofilmes , Fator A de Crescimento do Endotélio Vascular , Clorexidina , Gengiva , Temperatura , Titânio
9.
J Microbiol Methods ; 152: 52-60, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30017850

RESUMO

The aim of this study was to (i) design, develop and validate a practical and physiologically relevant reconstituted in vitro oral mucosa tissue model and (ii) to assess its applicability in in vitro host-pathogen interactions with C. albicans and S. aureus. Co-culture organotypic constructions were created by incorporating specific numbers of keratinocytes (NOK-si) onto cellularised, collagen gel scaffolds containing human gingival fibroblasts incubated in KGM media and cultured for 14 days. The detection of the appropriate oral mucosa/epithelial structure was evaluated by histology (hematoxylin and eosin (HE), periodic acid-Schiff (P.A.S.) and Picrosirius red), and immunocytochemistry (cytokeratin 13, cytokeratin 14, Ki-67 and collagen IV) compared to a normal human gingiva. The morphology of the reconstituted tissue was analyzed by Transmission Electron Microscopy. To further quantitate tissue damage, lactate dehydrogenase (LDH) was measured in the tissue supernatant. NOK-si grown upon a gingival scaffold provided an organotypic model in an in vitro setting and exhibited structural characteristics typically associated with normal oral mucosa. Immunocytochemistry revealed the detection of epithelial cytokeratins 13 and 14, Col IV and Ki-67 in the reconstituted oral mucosa model. Infection was detected after 8 h and 16 h. This study presents an in vitro cellularised, organotypic model of reconstituted oral mucosa, which enables close control and characterization of its structure and differentiation over a mid-length period of time in culture.


Assuntos
Técnicas de Cultura de Células/métodos , Interações Hospedeiro-Patógeno/fisiologia , Mucosa Bucal/metabolismo , Mucosa Bucal/microbiologia , Candida albicans , Candidíase/imunologia , Candidíase/microbiologia , Células Cultivadas , Técnicas de Cocultura/métodos , Colágeno , Colágeno Tipo IV , Células Epiteliais/microbiologia , Células Epiteliais/patologia , Fibroblastos , Gengiva/patologia , Humanos , Imuno-Histoquímica , Queratina-13/metabolismo , Queratina-14/metabolismo , Queratinócitos/patologia , Antígeno Ki-67/metabolismo , Mucosa Bucal/imunologia , Mucosa Bucal/patologia , Infecções Estafilocócicas/imunologia , Infecções Estafilocócicas/microbiologia , Staphylococcus aureus , Engenharia Tecidual , Tecidos Suporte
10.
Colloids Surf B Biointerfaces ; 170: 505-513, 2018 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-29960951

RESUMO

Silver tungstate (α-Ag2WO4) microcrystals have shown encouraging results regarding their antimicrobial activity. However, in addition to the promising outcomes in fighting oral disease, cytotoxic tests are mandatory for screening new materials for biological applications. Here, we developed a better understanding of the effects of microcrystals on the behavior of both human gingival fibroblast (HGF) cells and three-dimensional (3D) collagen matrices. To perform these experiments, the lowest concentration of α-Ag2WO4 capable of preventing the visible growth of Candida albicans (C. albicans) planktonic cells was defined as the test concentration, and it ranged from 0.781 (C1) to 7.81 (C2) to 78.1 (C3) µg/mL. Complete medium and lysis buffer (LB) served as negative (C-) and positive (C+) controls, respectively. The effect of the microcrystal concentration on the morphology, remodeling and proliferation of HGF cells was evaluated by different approaches. Quantitative and qualitative assessments demonstrated that α-Ag2WO4 did not affect the mitochondrial enzymatic activity of HGF cells cultured in a monolayer or the cell viability within 3D collagen matrices. These experiments showed that α-Ag2WO4 at the C2 concentration did not damage the genomic DNA. The development of new materials is attractive for the possible treatment of diseases and for avoiding indiscriminate prescribing of antibiotics. These findings provide information on the effect of α-Ag2WO4 on cell behavior and reveal that these microcrystals are non-cytotoxic against human gingival cells over a sufficient period to measure the hazard potential.


Assuntos
Colágeno/química , Fibroblastos/efeitos dos fármacos , Gengivite/tratamento farmacológico , Nanopartículas Metálicas/química , Prata/farmacologia , Compostos de Tungstênio/farmacologia , Antibacterianos/química , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Gengiva/citologia , Gengiva/microbiologia , Gengivite/microbiologia , Gengivite/patologia , Humanos , Modelos Moleculares , Tamanho da Partícula , Espécies Reativas de Oxigênio/metabolismo , Prata/química , Prata/uso terapêutico , Propriedades de Superfície , Compostos de Tungstênio/química , Compostos de Tungstênio/uso terapêutico
11.
BMC Microbiol ; 17(1): 146, 2017 06 30.
Artigo em Inglês | MEDLINE | ID: mdl-28666415

RESUMO

BACKGROUND: The objective of this study was to better understand the effects of soluble factors from biofilm of single- and mixed-species Candida albicans (C. albicans) and methicillin-sensitive Staphylococcus aureus (MSSA) cultures after 36 h in culture on keratinocytes (NOK-si and HaCaT) and macrophages (J774A.1). Soluble factors from biofilms of C. albicans and MSSA were collected and incubated with keratinocytes and macrophages, which were subsequently evaluated by cell viability assays (MTT). Lactate dehydrogenase (LDH) enzyme release was measured to assess cell membrane damage to keratinocytes. Cells were analysed by brightfield microscopy after 2 and 24 h of exposure to the soluble factors from biofilm. Cell death was detected by labelling apoptotic cells with annexin V and necrotic cells with propidium iodide (PI) and was visualized via fluorescence microscopy. Soluble factors from biofilm were incubated with J774A.1 cells for 24 h; the subsequent production of NO and the cytokines IL-6 and TNF-α was measured by ELISA. RESULTS: The cell viability assays showed that the soluble factors of single-species C. albicans cultures were as toxic as the soluble factors from biofilm of mixed cultures, whereas the soluble factors of MSSA cultures were less toxic than those of C. albicans or mixed cultures. The soluble factors from biofilm of mixed cultures were the most toxic to the NOK-si and HaCaT cells, as confirmed by analyses of PI labelling and cell morphology. Soluble factors from biofilm of single-species MSSA and mixed-species cultures induced the production of IL-6, NO and TNF-α by J744A.1 macrophages. The production of IL-6 and NO induced by the soluble factors from biofilm of mixed cultures was lower than that induced by the soluble factors from biofilm of single-species MSSA cultures, whereas the soluble factors from biofilm of C. albicans cultures induced only low levels of NO. CONCLUSIONS: Soluble factors from 36-h-old biofilm of C. albicans and MSSA cultures promoted cell death and inflammatory responses.


Assuntos
Proteínas de Bactérias/farmacologia , Candida albicans/metabolismo , Queratinócitos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Staphylococcus aureus/metabolismo , Biofilmes/crescimento & desenvolvimento , Candida albicans/fisiologia , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Humanos , Interleucina-6/metabolismo , Queratinócitos/citologia , Queratinócitos/imunologia , Queratinócitos/metabolismo , Macrófagos/citologia , Macrófagos/imunologia , Macrófagos/metabolismo , Óxido Nítrico/metabolismo , Staphylococcus aureus/fisiologia , Fator de Necrose Tumoral alfa/metabolismo
12.
ACS Appl Mater Interfaces ; 9(13): 11472-11481, 2017 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-28291327

RESUMO

The electronic configuration, morphology, optical features, and antibacterial activity of metastable α-AgVO3 crystals have been discussed by a conciliation and association of the results acquired by experimental procedures and first-principles calculations. The α-AgVO3 powders were synthesized using a coprecipitation method at 10, 20, and 30 °C. By using a Wulff construction for all relevant low-index surfaces [(100), (010), (001), (110), (011), (101), and (111)], the fine-tuning of the desired morphologies can be achieved by controlling the values of the surface energies, thereby lending a microscopic understanding to the experimental results. The as-synthesized α-AgVO3 crystals display a high antibacterial activity against methicillin-resistant Staphylococcus aureus. The results obtained from the experimental and theoretical techniques allow us to propose a mechanism for understanding the relationship between the morphological changes and antimicrobial performance of α-AgVO3.


Assuntos
Antibacterianos/farmacologia , Anti-Infecciosos , Staphylococcus aureus Resistente à Meticilina , Óxidos , Compostos de Prata , Compostos de Vanádio
13.
J Prosthet Dent ; 118(4): 481-487, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-28343672

RESUMO

STATEMENT OF PROBLEM: Peri-implantitis is considered the most important biological complication responsible for late implant failure. The physical chemical properties intrinsic to each material can affect the first step to biofilm development and is an important precursor to the adaptive behavior of pathogenic bacteria species. PURPOSE: The purpose of this in vitro study was to evaluate the effect of 2 commercially available implant abutment materials on the adhesion phase and biofilm formation. MATERIAL AND METHODS: Disks (8 mm in diameter, 2 mm thick) of machined pure titanium (Ti) and yttrium-stabilized zirconia (ZrO2) materials were used to mimic implant abutments. The physical chemical surface properties were investigated using different approaches. Initial adherent bacteria and biofilm formation were evaluated after 16 and 48 hours by incubating the disks in a rich medium containing representative saliva-derived oral microbial community. Unpaired t test, 2 tailed, was used to compare the groups. RESULTS: Ti presented lower hydrophobicity and surface free energy values than the ZrO2, and 6.1-fold fewer bacteria adhered to the Ti. After 48 hours, detailed quantitative analysis showed that biofilm biomass and biofilm density were lower on the Ti disks than on ZrO2. The quantity of phylotypes on the Ti and ZrO2 surfaces was relatively similar during the attachment and early biofilm formation periods. CONCLUSIONS: Although no difference in the bacteria profile was observed between both materials independent of the time point, the highest level of colonization was on ZrO2.


Assuntos
Aderência Bacteriana , Biofilmes , Dente Suporte , Implantes Dentários , Saliva/microbiologia , Titânio , Zircônio , Projeto do Implante Dentário-Pivô , Humanos , Técnicas In Vitro
14.
Photodiagnosis Photodyn Ther ; 17: 236-244, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-27939958

RESUMO

According to the American Academy of Implant Dentistry, 3 million Americans have dental implants, and this number is growing by 500,000 each year. Proportionally, the number of biological complications is also increasing. Among them, peri-implant disease is considered the most common cause of implant loss after osseointegration. In this context, microorganisms residing on the surfaces of implants and their prosthetic components are considered to be the primary etiologic factor for peri-implantitis. Some research groups have proposed combining surgical and non-surgical therapies with systemic antibiotics. The major problem associated with the use of antibiotics to treat peri-implantitis is that microorganisms replicate very quickly. Moreover, inappropriate prescription of antibiotics is not only associated with potential resistance but also and most importantly with the development of superinfections that are difficult to eradicate. Although antimicrobial photodynamic therapy (aPDT) was discovered several years ago, aPDT has only recently emerged as a possible alternative therapy against different oral pathogens causing peri-implantitis. The mechanism of action of aPDT is based on a combination of a photosensitizer drug and light of a specific wavelength in the presence of oxygen. The reaction between light and oxygen produces toxic forms of oxygen species that can kill microbial cells. This mechanism is crucial to the efficacy of aPDT. To help us understand conflicting data, it is necessary to know all the particularities of the etiology of peri-implantitis and the aPDT compounds. We believe that this review will draw attention to new insights regarding the impact of aPDT on peri-implant disease.


Assuntos
Anti-Infecciosos/uso terapêutico , Peri-Implantite/tratamento farmacológico , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/uso terapêutico , Biofilmes/crescimento & desenvolvimento , Sobrevivência Celular , Implantes Dentários/microbiologia , Placa Dentária/metabolismo , Células Epiteliais/microbiologia , Gengiva/microbiologia , Humanos , Mediadores da Inflamação/metabolismo , Peri-Implantite/imunologia , Fatores de Risco
15.
J Prosthodont ; 26(7): 606-610, 2017 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26683409

RESUMO

PURPOSE: This clinical study evaluated the effect of microwave disinfection protocols on the occlusal pressure pattern of dentures. MATERIALS AND METHODS: Dentures were constructed for 40 patients and evaluated as follows (n = 20). Group 1: Patients had the maxillary dentures submitted to microwave disinfection, once a week, for 4 weeks. Group 2: Patients had the maxillary dentures submitted to microwave disinfection, three times a week, for 4 weeks. Occlusal contacts were recorded on five occasions: 30 days after denture insertion and before first disinfection (baseline or control group); 1 week after disinfection; 2 weeks after disinfection; 3 weeks after disinfection; 4 weeks after disinfection. Occlusal contacts were analyzed by T-Scan III. Intergroup analysis was performed using the Mann-Whitney test and intragroup analysis using the Friedman test with significance of 5%. RESULTS: The results showed no significant difference between groups during the periods. The data on parameters loss of denture adaptation or complaints showed that patients used their dentures regularly for eating and expressed comfort and satisfaction in all experimental periods. The evaluation of functional occlusion revealed that the distribution of the occlusal contacts remained unaltered after disinfection. CONCLUSION: Microwave disinfection protocols as studied in this report did not influence occlusal contacts of the complete dentures.


Assuntos
Oclusão Dentária , Prótese Total , Desinfecção/métodos , Micro-Ondas/uso terapêutico , Adulto , Idoso , Idoso de 80 Anos ou mais , Análise do Estresse Dentário , Humanos , Pessoa de Meia-Idade
16.
PLoS One ; 11(5): e0155427, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27224027

RESUMO

Considering the ability of atmospheric-pressure cold plasma (ACP) to disrupt the biofilm matrix and rupture cell structure, it can be an efficient tool against virulent oral biofilms. However, it is fundamental that ACP does not cause damage to oral tissue. So, this study evaluated (1) the antimicrobial effect of ACP on single- and dual-species biofilms of Candida albicans and Staphylococcus aureus as well as (2) the biological safety of ACP on in vitro reconstituted oral epithelium. Standardized cell suspensions of each microorganism were prepared for biofilm culture on acrylic resin discs at 37°C for 48 hours. The biofilms were submitted to ACP treatment at 10 mm of plasma tip-to-sample distance during 60 seconds. Positive controls were penicillin G and fluconazole for S. aureus and C. albicans, respectively. The biofilms were analyzed through counting of viable colonies, confocal laser scanning microscopy, scanning electron microscopy and fluorescence microscopy for detection of reactive oxygen species. The in vitro reconstituted oral epithelium was submitted to similar ACP treatment and analyzed through histology, cytotoxocity test (LDH release), viability test (MTT assay) and imunnohistochemistry (Ki67 expression). All plasma-treated biofilms presented significant log10 CFU/mL reduction, alteration in microorganism/biofilm morphology, and reduced viability in comparison to negative and positive controls. In addition, fluorescence microscopy revealed presence of reactive oxygen species in all plasma-treated biofilms. Low cytotoxicity and high viability were observed in oral epithelium of negative control and plasma group. Histology showed neither sign of necrosis nor significant alteration in plasma-treated epithelium. Ki67-positive cells revealed maintenance of cell proliferation in plasma-treated epithelium. Atmospheric-pressure cold plasma is a promissing approach to eliminate single- and dual-species biofilms of C. albicans and S. aureus without having toxic effects in oral epithelium.


Assuntos
Argônio/farmacologia , Pressão Atmosférica , Biofilmes/crescimento & desenvolvimento , Candida albicans/fisiologia , Mucosa Bucal/microbiologia , Gases em Plasma/farmacologia , Staphylococcus aureus/fisiologia , Células Epiteliais/microbiologia , Feminino , Humanos , Masculino
17.
Photochem Photobiol Sci ; 15(5): 682-90, 2016 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-27110908

RESUMO

This study assessed the cytotoxicity of antimicrobial Photodynamic Inactivation (aPDI), mediated by curcumin, using human keratinocytes co-cultured with Candida albicans. Cells and microorganisms were grown separately for 24 hours and then kept in contact for an additional 24 hours. After this period, aPDI was applied. The conditions tested were: P+L+ (experimental group aPDI); P-L+ (light emitting diode [LED] group); P+L- (curcumin group); and P-L- (cells in co-culture without curcumin nor LED). In addition, keratinocytes and C. albicans were grown separately, were not placed in the co-culture and did not receive aPDI (control group). Cell proliferation was assessed using Alamar Blue, MTT, XTT and CFU tests. Qualitative and quantitative analyses were performed. Analysis of variance (ANOVA) was applied to the survival percentages of cells compared to the control group (considered as 100% viability), complemented by multiple comparisons using Tukey's test. A 5% significance level was adopted. The results of this study showed no interference in the metabolism of the cells in co-culture, since no differences were observed between the control group (cultured cells by themselves) and the P-L- group (co-culture cells without aPDI). The aPDI group reached the highest reduction (p = 0.009), which was equivalent to 1.7 log10 when compared to the control group. The P+L-, P-L+, P-L- and control groups were not statistically different (ρ > 0.05). aPDI inhibited the growth of keratinocytes and C. albicans in all tests, so the therapy was considered slightly (inhibition between 25 and 50% compared to the control group) to moderately (inhibition between 50 and 75% compared to the control group) cytotoxic.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Candida albicans/efeitos da radiação , Candidíase/tratamento farmacológico , Curcumina/farmacologia , Queratinócitos/microbiologia , Fármacos Fotossensibilizantes/farmacologia , Biofilmes/efeitos dos fármacos , Linhagem Celular , Técnicas de Cocultura , Humanos , Luz
18.
Lasers Med Sci ; 31(5): 997-1009, 2016 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-27126412

RESUMO

This study evaluated the potential of curcumin-mediated antimicrobial photodynamic inactivation (API) on multispecies biofilms of Candida albicans, Candida glabrata, and Streptococcus mutans of different ages. Acrylic samples (n = 480) were made with standardized rough surfaces and incubated with bacteria and yeast for 24 or 48 h. API was performed with curcumin (80, 100, 120 µM) and LED light. Additional acrylic samples were treated with curcumin or LED light only. Positive control samples received neither light nor curcumin. After API, colony counts were quantified (CFU/mL), cell metabolism was determined by means of XTT assay, and the total biofilm biomass was evaluated using Crystal Violet (CV) staining assay and images were obtained by confocal laser scanning microscopy (CLSM). The data were analyzed by nonparametric two-way ANOVA and post hoc Tukey tests (α < 0.05). For 24-h biofilm, API resulted in statistically significant difference (ρ < 0.001) of viability of C. albicans compared with control (P-L-) for all Cur concentrations. For 48-h biofilm, API resulted in statistically significant difference (ρ < 0.001) compared with control only when Cur at 120 µM was used. API promoted statistically significant difference (ρ ≤ 0.001) in the viability of S. mutans and C. glabrata for all Cur concentrations in the two biofilm ages. In addition, API produced a statistically significant difference (ρ < 0.001) of metabolic activity and of total biomass (ρ < 0.001) of multispecies biofilms compared with control for all Cur concentrations. It can be concluded that both 24- and 48-h biofilms were susceptible to API mediated by Cur; however, 24-h biofilm was more sensitive than the 48-h biofilm.


Assuntos
Anti-Infecciosos/farmacologia , Biofilmes/efeitos dos fármacos , Candida/efeitos dos fármacos , Curcumina/farmacologia , Fotoquimioterapia/métodos , Streptococcus mutans/efeitos dos fármacos , Candida/fisiologia , Microscopia Confocal , Streptococcus mutans/fisiologia
19.
J Microbiol Methods ; 125: 40-2, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-27060444

RESUMO

This study assessed the effect of the buffers 4-(2-hydroxyethyl)-1-piperazineethanesulfonic acid (HEPES) and 3-(N-morpholino) propanesulfonic acid (MOPS) on keratinocyte cell viability and microbial growth. It was observed that RPMI buffered with HEPES, supplemented with l-glutamine and sodium bicarbonate, can be used as a more suitable medium to promote co-culture.


Assuntos
Sobrevivência Celular/efeitos dos fármacos , Meios de Cultura/química , HEPES/farmacologia , Queratinócitos/fisiologia , Morfolinas/farmacologia , Staphylococcus aureus/crescimento & desenvolvimento , Animais , Biofilmes/efeitos dos fármacos , Biofilmes/crescimento & desenvolvimento , Tampões (Química) , Linhagem Celular , Células Cultivadas , HEPES/química , Humanos , Concentração de Íons de Hidrogênio , Queratinócitos/efeitos dos fármacos , Morfolinas/química , Morfolinas/toxicidade , Staphylococcus aureus/efeitos dos fármacos
20.
J Prosthet Dent ; 115(4): 428-36, 2016 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-26597465

RESUMO

STATEMENT OF PROBLEM: The longevity of dental implants depends on the absence of inflammation in the periimplant tissue. Similar to teeth, pathogenic bacteria can adhere on implant abutment surfaces and cause periimplant disease and consequently implant loss. PURPOSE: The purpose of this in vitro study was to evaluate the influence of physical and chemical properties of 2 common materials used as implant abutments, titanium (Ti) and zirconia (ZrO2), and the use of bovine enamel (BE) as a positive control on biofilm formation. MATERIAL AND METHODS: Biofilm formation was analyzed by growing Porphyromonas gingivalis and Fusobacterium nucleatum as monospecies and mixed species biofilms on the surfaces. The mean roughness (Ra) and surface free energy were evaluated for each material. Mature biofilm, formed after 7 days of incubation, was analyzed quantitatively and qualitatively by colony-forming unit and confocal laser scanning microscopy. RESULTS: The mean roughness in all disks was ≤0.21 µm and did not affect the bacterial adhesion. Titanium showed a greater degree of hydrophilicity compared with BE after 90 minutes of immersion in saliva. The surface free energy did not show differences, with the highest values for BE. Monospecies biofilms formed by P. gingivalis on Ti, and mixed species biofilm on ZrO2 exhibited small numbers of cells on disk surfaces. By confocal imaging, the mixed species biofilm appeared as a thin layer on ZrO2 surfaces. CONCLUSIONS: Material surfaces could have a significant impact on biofilm formation. ZrO2 implant abutment surfaces showed a decrease in anaerobic biofilm compared with Ti and BE.


Assuntos
Biofilmes , Projeto do Implante Dentário-Pivô , Implantes Dentários/microbiologia , Materiais Dentários/química , Aderência Bacteriana , Humanos , Propriedades de Superfície , Titânio
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