Unvealing the role of ß-Ag2MoO4 microcrystals to the improvement of antibacterial activity.

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.

Os cuidados da Estratégia Saúde da Família a um adolescente vítima de bullying: uma cartografia / Mapping the provision of care to an adolescent victim of school bullying by the Family Health Strategy in Brazil

Resumo O cuidado ao adolescente envolvido em situações de "bullying" é necessariamente intersetorial, de tal modo que ultrapassa os limites do cenário escolar e amplia-se para o setor da saúde. Partindo desse princípio, este estudo buscou cartografar a produção do cuidado ofertada a um adolescente em situações de "bullying" pela Estratégia Saúde da Família. Para tal fim, foi utilizado o método da cartografia, através do fluxograma analisador e do diário de campo. Deste modo, mapas do cuidar foram produzidos pelos profissionais de saúde, entretanto esse cuidar mostrou-se descompassado, árido e pouco resolutivo. Apesar disso, através do uso dos instrumentos de pesquisa, foi possível inaugurar outras formas de amparo ao adolescente. A equipe, ao visualizar seu trajeto em busca de suporte, repensou modos engessados de fazer saúde e, assim, tornou-se possível produzir um cuidado com outras possibilidades de vida, para além do aspecto biológico. A atenção à saúde do adolescente envolvido com o "bullying" mostrou-se oscilante na Estratégia Saúde da Família. No entanto, por meio da cartografia, ficou evidente o papel crucial da atenção primária em suportar o adolescente, o que poderia contribuir para a cessação do ciclo da violência.

Abstract The provision of care to adolescents who are victims of bullying is necessarily intersectoral and, as such, goes beyond the limits of the school context. Underpinned by this principle, this study mapped the care provided to an adolescent victim of bullying by the Family Health Strategy, using cartography to elaborate an analytical flow chart of the pathway taken by the patient through the health service. The care maps produced by the health professionals involved in the process showed that care was out of step, dry and had a low level of resolvability. Despite these findings, the use of this instrument allowed the health team to propose other forms of support for the adolescent. After visualizing the pathway taken by the patient through the care network, the team was able to rethink limiting approaches to health care and discover other care possibilities that go beyond physical dimensions. The care provided by the Family Health Strategy was shown to be inconsistent. However, the mapping activity clearly showed that primary care services play a crucial role in providing appropriate support to adolescent victims of bullying and breaking the cycle of violence.

Mapping the provision of care to an adolescent victim of school bullying by the Family Health Strategy in Brazil. / Os cuidados da Estratégia Saúde da Família a um adolescente vítima de bullying: uma cartografia.

The provision of care to adolescents who are victims of bullying is necessarily intersectoral and, as such, goes beyond the limits of the school context. Underpinned by this principle, this study mapped the care provided to an adolescent victim of bullying by the Family Health Strategy, using cartography to elaborate an analytical flow chart of the pathway taken by the patient through the health service. The care maps produced by the health professionals involved in the process showed that care was out of step, dry and had a low level of resolvability. Despite these findings, the use of this instrument allowed the health team to propose other forms of support for the adolescent. After visualizing the pathway taken by the patient through the care network, the team was able to rethink limiting approaches to health care and discover other care possibilities that go beyond physical dimensions. The care provided by the Family Health Strategy was shown to be inconsistent. However, the mapping activity clearly showed that primary care services play a crucial role in providing appropriate support to adolescent victims of bullying and breaking the cycle of violence.

O cuidado ao adolescente envolvido em situações de "bullying" é necessariamente intersetorial, de tal modo que ultrapassa os limites do cenário escolar e amplia-se para o setor da saúde. Partindo desse princípio, este estudo buscou cartografar a produção do cuidado ofertada a um adolescente em situações de "bullying" pela Estratégia Saúde da Família. Para tal fim, foi utilizado o método da cartografia, através do fluxograma analisador e do diário de campo. Deste modo, mapas do cuidar foram produzidos pelos profissionais de saúde, entretanto esse cuidar mostrou-se descompassado, árido e pouco resolutivo. Apesar disso, através do uso dos instrumentos de pesquisa, foi possível inaugurar outras formas de amparo ao adolescente. A equipe, ao visualizar seu trajeto em busca de suporte, repensou modos engessados de fazer saúde e, assim, tornou-se possível produzir um cuidado com outras possibilidades de vida, para além do aspecto biológico. A atenção à saúde do adolescente envolvido com o "bullying" mostrou-se oscilante na Estratégia Saúde da Família. No entanto, por meio da cartografia, ficou evidente o papel crucial da atenção primária em suportar o adolescente, o que poderia contribuir para a cessação do ciclo da violência.

Effect of surface characteristics of soft liners and tissue conditioners and saliva on the adhesion and biofilm formation.

PURPOSE: To investigate the influence of surface characteristics and saliva on the adhesion and biofilm formation of Candida glabrata and methicillin-resistant Staphylococcus aureus (MRSA) to soft liners and tissue conditioners. METHODS: For each material (Ufi Gel P - UG; Sofreliner S - SS; Trusoft - TR; Coe Comfort - CC; Softone - ST), specimens were prepared and roughness (Ra), hydrophobicity (water contact angles-WCA) and surface free energy (SFE) were measured. Surface morphology was also analyzed using scanning electron microscopy (SEM). Specimens were incubated in C. glabrata or MRSA suspensions for 90 minutes (adhesion) or 48 hours (biofilm). The absorbance (AB) was measured by XTT assay. Experiments were performed using specimens that were either uncoated or had been coated with saliva. Data were analyzed using one- or two-way ANOVAs, followed by Tukey's test (α= 0.05). RESULTS: TR exhibited the highest Ra and UG the lowest. SEM images also showed that UG and SS had smooth surfaces, while TR presented several irregularities and pores. In the absence of saliva, UG and SS presented higher WCA and lower SFE than the other materials. XTT results showed that, in the C. glabrata adhesion assay, the AB value was higher for TR followed by UG > CC> SS> ST. For the biofilm formation of C. glabrata, AB values were in the following order TR > CC = UG > ST = SS. In the adhesion assay, AB values obtained for MRSA were TR > UG = CC > ST > SS and for the biofilm formation were TR > ST > CC > UG > SS. Saliva decreased the WCA and increased the SFE for all materials. In general, the presence of saliva decreased the adhesion and biofilm formation of both microorganisms to the acrylic-based material (TR) and tissue conditioners (CC and ST), and increased for the silicone-based soft liners (UH and SS). Surface characteristics and the influence of saliva varied among materials. Roughness seemed to favor C. glabrata and MRSA adhesion and biofilm formation. CLINICAL SIGNIFICANCE: The presence of microorganisms on denture liners can irritate the oral tissues and contribute to systemic diseases. Colonization with more tolerant microorganisms such as C. glabrata and MRSA may expose patients to a greater risk of infection, mainly in immunocompromised hosts, such as aged individuals after treatment of oral cancer. For this, it is important to investigate the surface characteristics of soft liners and tissue conditioners, as well as saliva, and their influence on the adhesion and biofilm formation of C. glabrata and methicillin-resistant Staphylococcus aureus.

Mechanism of Antibacterial Activity via Morphology Change of α-AgVO3: Theoretical and Experimental Insights.

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.

Occlusal Pressure Analysis of Complete Dentures after Microwave Disinfection: A Clinical Study.

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.

Bullying during adolescence in Brazil: an overview.

Bullying has been the subject of worldwide study for over four decades and is widely reported by social media. Despite this, the issue is a relatively new area of research in Brazil. This study analyzes academic literature addressing bullying produced in Brazil focusing on aspects that characterize this issue as a subtype of violence: gender differences, factors associated with bullying, consequences, and possible intervention and prevention approaches. The guiding question of this study was: what have Brazilian researchers produced regarding bullying among adolescents? The results show that over half of the studies used quantitative approaches, principally cross-sectional methods and questionnaires, and focused on determining the prevalence of and factors associated with bullying. The findings showed a high prevalence of bullying among Brazilian adolescents, an association between risk behavior and bullying, serious consequences for the mental health of young people, lack of awareness and understanding among adolescents about bullying and its consequences, and a lack of strategies to manage this type of aggression. There is a need for intervention studies, prevention and restorative practices that involve the community and can be applied to everyday life at school.

Bullying na adolescência: visão panorâmica no Brasil / Bullying during adolescence in Brazil: an overview

Resumo Embora o bullying seja um tema amplamente disseminado nas mídias sociais e estudado internacionalmente há mais de quatro décadas, no Brasil, somente passou a ser objeto de estudo a partir do final da década de 90 e início do ano 2000. Para compreender a produção científica nacional acerca deste tema, considerou-se aspectos que o caracterizam como subtipo de violência, diferença entre gêneros, fatores associados, consequências e possíveis abordagens intervencionistas e preventivas. A pergunta norteadora desta revisão integrativa foi “O que têm produzido pesquisadores brasileiros acerca do bullying entre adolescentes?” – sendo realizada através de sete bases de dados. Os dados mostram que mais da metade das pesquisas são de cunho quantitativo, através de estudos transversais e aplicação de questionários, visando estabelecer a ocorrência do bullying e seus fatores associados. Demonstrou a significante incidência de bullying entre os adolescentes brasileiros, a relação com comportamentos de risco, as graves consequências à saúde mental dos jovens, a falta de compreensão desta faixa etária sobre o que é o bullying e a escassez de estratégias de manejo deste tipo de agressão. Indica-se a importância de estudos preventivos, interventivos e restaurativos que envolvam a comunidade e que façam parte do cotidiano escolar.

Abstract Bullying has been the subject of worldwide study for over four decades and is widely reported by social media. Despite this, the issue is a relatively new area of research in Brazil. This study analyzes academic literature addressing bullying produced in Brazil focusing on aspects that characterize this issue as a subtype of violence: gender differences, factors associated with bullying, consequences, and possible intervention and prevention approaches. The guiding question of this study was: what have Brazilian researchers produced regarding bullying among adolescents? The results show that over half of the studies used quantitative approaches, principally cross-sectional methods and questionnaires, and focused on determining the prevalence of and factors associated with bullying. The findings showed a high prevalence of bullying among Brazilian adolescents, an association between risk behavior and bullying, serious consequences for the mental health of young people, lack of awareness and understanding among adolescents about bullying and its consequences, and a lack of strategies to manage this type of aggression. There is a need for intervention studies, prevention and restorative practices that involve the community and can be applied to everyday life at school.

Susceptibility of multispecies biofilm to photodynamic therapy using Photodithazine®.

This in vitro study evaluated the effect of photodynamic therapy (PDT) on the multispecies biofilm of Candida albicans, Candida glabrata, and Streptococcus mutans. Standardized fungal and bacterial suspensions were cultivated appropriately for each species and inoculated in 96-well microtiter plates for mix-biofilm formation. After 48 h of incubation, the biofilms were submitted to PDT (P + L+) using Photodithazine® (PDZ) at 100, 150, 175, 200, or 250 mg/mL for 20 min and 37.5 J/cm(2) of light-emitting diode (LED) (660 nm). Additional samples were treated only with PDZ (P + L-) or LED (P-L+), or neither (control, P-L-). Afterwards, the biofilms were evaluated by quantification of colonies (CFU/mL), metabolic activity (XTT reduction assay), total biomass (crystal violet staining), and confocal scanning laser microscopy (CSLM). Data were analyzed by one-way ANOVA and Tukey tests (p < 0.05). Compared with the control, PDT promoted a significant reduction in colonies viability of the three species evaluated with 175 and 200 mg/mL of PDZ. PDT also significantly reduced the metabolic activity of the biofilms compared with the control, despite the PDZ concentration. However, no significant difference was found in the total biomass of samples submitted or not to PDT. For all analysis, no significant difference was verified among P-L-, P + L-, and P-L+. CSLM showed a visual increase of dead cells after PDT. PDT-mediated PDZ was effective in reducing the cell viability of multispecies biofilm.

Effects of soft denture liners on L929 fibroblasts, HaCaT keratinocytes, and RAW 264.7 macrophages.

The effects of six soft liners (Ufi Gel P (UG), Sofreliner S (SR), Durabase Soft (D), Trusoft (T), Coe Comfort (CC), and Softone (ST)) on L929, HaCat, and RAW 264.7 cells were investigated. Eluates (24 and 48 h) from the materials were applied on the cells and the viability, type of cell death, and morphology were evaluated. Cells were also seeded on the specimens' surfaces (direct contact) and incubated (24 or 48 h), and viability was analyzed. Controls were cells in culture medium without eluates or specimens. For cell viability, no significant differences were found among materials or between extraction periods, and the liners were noncytotoxic or slightly cytotoxic. Morphology of RAW 264.7 cells was altered by the 24 h eluates from CC and D and the 48 h eluates from SR, CC, and D. The 24 and 48 h eluates from all materials (except T) increased the percentages of L929 necrotic cells. For direct contact tests, the lowest cytotoxicity was observed for UG and SR. Although eluates did not reduce viability, morphology alterations and increase in necrosis were seen. Moreover, in the direct contact, effects on viability were more pronounced, particularly for D, T, CC and ST. Thus, the use of UG and SR might reduce the risk of adverse effects.

O uso do método história oral nas pesquisas qualitativas: contribuições para a temática do cuidado em saúde mental / Use of the method oral history in qualitative research: contributions for the mental helth care thematic abstract

As pesquisas qualitativas em saúde mental vêm priorizando investigaçõessobre o cuidado percebido dentro de uma conjuntura de transformaçõessociais, políticas, culturais, ideológicas e comportamentais que têm marcadoa saúde mental nos últimos anos. O artigo objetiva discutir o uso do métododa história oral desde a sua concepção até os dias atuais e sua possívelcontribuição nas pesquisas qualitativas em saúde mental dentro desse novocontexto. A história da assistência psiquiátrica sempre esteve permeada porexperiências de exclusão e estigmatização, e o uso desse método possibilitadar voz àqueles que durante anos foram silenciados, bem como narrar ahistória da transformação da atenção em saúde mental, na perspectiva dosnovos protagonistas do cuidado...

The qualitative research in mental health have been prioritizinginvestigations over the perceived care within a conjecture of social, political,cultural, ideological and behavioral changes that have been marking themental health field in the past years. The article aims to discuss the OralHistory methodology since its conception until the present days and itspossible contributions to the qualitative research in mental health within thisnew context. The history of psychiatry assistance has always been permeated by experiences of exclusion and stigmatization, and the usage of this methodology allows ones to give voice to those who for years were silenced, as well as narrates the history of the transformations of the care offered in mental health in the perspective of the new protagonists of attention...

In vitro evaluation of the enzymatic activity profile of non-albicans Candida species isolated from patients with oral candidiasis with or without diabetes.

OBJECTIVE: To evaluate the expression of phospholipase (PL) and secreted aspartyl proteinase (SAP) by Candida glabrata and C tropicalis obtained from the denture biofilms of healthy participants (16 isolates), patients with oral candidiasis with diabetes (10 isolates), and patients with oral candidiasis without diabetes (25 isolates). STUDY DESIGN: After incubation, the supernatants and pellets of the isolates were used for the enzymatic assays and quantification of colony-forming units (CFU), respectively. Colorimetric tests were used with phosphatidylcholine as a substrate for PL and azocasein as a substrate for SAP, and the absorbances of the samples were measured. Enzymatic rates were calculated, and values were normalized by CFU. Results were analyzed with factorial analyses of variance (α = .05). RESULTS: C tropicalis and C glabrata were proteolytic and phospholipolytic. The clinical sources of isolates had no significant effect on the enzymatic activities (P > .05). C tropicalis had significantly higher enzymatic activity for both PL and SAP (P < .001) than did C glabrata. CONCLUSIONS: C tropicalis isolates produced significantly higher amounts of both enzymes than did the C glabrata isolates.

In vitro evaluation of adherence of Candida albicans, Candida glabrata, and Streptococcus mutans to an acrylic resin modified by experimental coatings.

This study evaluated the effect of experimental coatings, containing zwitterion or hydrophilic monomers, on the adherence of Candida albicans, Candida glabrata, and Streptococcus mutans to an acrylic resin. Acrylic samples (smooth or rough surfaces) were left untreated (control) or coated with one of the following experimental coatings: 3-hydroxypropylmethacrylate (HP) or sulfobetaine methacrylate (S), at concentrations of 25, 30, or 35%. Half of the specimens were coated with saliva. The adhesion test was performed by incubating specimens in C. albicans, C. glabrata, and S. mutans suspensions at 37°C for 90 min. The number of adhered microorganisms was determined by metabolic activity (XTT) and by cell viability (CFU). All coated specimens exhibited lower absorbance and CFU values compared to control specimens. Saliva and roughness did not promote microorganism adherence. An XPS analysis confirmed the modification in the chemical composition of the coatings in the experimental samples. These experimental coatings significantly reduced the adherence of C. albicans, C. glabrata and S. mutans to acrylic resin.

Enzymatic activity profile of a Brazilian culture collection of Candida albicans isolated from diabetics and non-diabetics with oral candidiasis.

The secretion of hydrolytic enzymes is a fundamental virulence factor of Candida albicans to develop disease. The objective of this study was to characterise the virulence of 148 clinical isolates of C. albicans from oral candidiasis by assessing the expression of phospholipase (PL) and secreted aspartyl proteinase (SAP). Isolates were obtained from healthy subjects (HS) and diabetics (DOC) and non-diabetics with oral candidiasis (NDOC). An aliquot (5 µl) of each cell suspension was inoculated on PL and SAP agar plates and incubated. Enzymes secretion was detected by the formation of an opaque halo around the colonies and enzymatic activity (PZ) was determined by the ratio between colony diameter and colony diameter plus the halo zone. Statistical comparisons were made by a one-way anova followed by Tukey's post hoc test (α = 0.05). The clinical sources of C. albicans had significant effect (P < 0.001) on the PZ values of both enzymes. For PL, clinical isolates from NDOC and DOC had highest enzymatic activity than those from HS (P < 0.05), with no significant differences between them (P = 0.506). For SAP, C. albicans from NDOC showed the lower enzymatic activity (P < 0.001). There were no significant differences between isolates from HS and DOC (P = 0.7051). C. albicans isolates from NDOC and DOC patients showed an increased production of PL.

Candida albicans adherence to an acrylic resin modified by experimental photopolymerised coatings: an in vitro study.

PURPOSE: This study evaluated whether photopolymerised coatings containing zwitterion or hydrophilic monomers would reduce the adhesion of Candida albicans to an acrylic resin. MATERIALS AND METHODS: Disc-shaped samples (n = 468) were fabricated with rough or smooth surfaces. The samples did not receive any surface treatment (control) or were coated with one of the following experimental coatings (2-hydroxyethyl methacrylate - HE; 3-hydroxypropyl methacrylate - HP; and 2-trimethylammonium ethyl methacrylate chloride - T; and sulfobetaine methacrylate - S). The concentrations of the constituent monomers were 25, 30 or 35%. The water contact angles of the samples were measured, and half of the samples were exposed to saliva. The adherent yeast cells were counted after crystal violet staining. RESULTS: For the smooth samples, the groups S35, HP35 and HE35 showed significantly lower number of adhered Candida than control, in the absence of saliva. There were no significant differences among the experimental and control groups for the rough samples, but the saliva decreased the cell numbers for groups S25, S30 and HP30. The photoelectron spectroscopy analysis confirmed the changes in the chemical compositions of the experimental samples. CONCLUSIONS: The experimental photopolymerised coatings changed the chemical composition and decreased C. albicans adhesion in the groups S35, HP35 and HE35, suggesting that they should be further investigated.

Adhesive bonding of resin composite to various titanium surfaces using different metal conditioners and a surface modification system

Objective: This study evaluated the effect of three metal conditioners on the shear bond strength (SBS) of a prosthetic composite material to cpTi grade I having three surface treatments. Material and Methods: One hundred sixty eight rivet-shaped specimens (8.0x2.0 mm) were cast and subjected to polishing (P) or sandblasting with either 50 mm (50SB) or 250 mm (250SB) Al2O3. The metal conditioners Metal Photo Primer (MPP), Cesead II Opaque Primer (OP), Targis Link (TL), and one surface modification system Siloc (S), were applied to the specimen surfaces, which were covered with four 1-mm thick layers of resin composite. The resin layers were exposed to curing light for 90 s separately. Seven specimens from each experimental group were stored in water at 37ºC for 24 h while the other 7 specimens were subjected to 5,000 thermal cycles consisting of water baths at 4ºC and 60ºC (n=7). All specimens were subjected to SBS test (0.5 mm/min) until failure occurred, and further 28 specimens were analyzed using scanning electron microscope (SEM) and X-ray energy-dispersive spectroscopy (EDS). Data were analyzed by 3-way ANOVA followed by post-hoc Tukey's test (α=0.05). Results: On 50SB surfaces, OP groups showed higher SBS means than MPP (P<0.05), while no significant difference was found among OP, S, and TL groups. On 250SB surfaces, OP and TL groups exhibited higher SBS than MPP and S (P<0.05). No significant difference in SBS was found between OP and TL groups nor between MPP and S groups. The use of conditioners on 250SB surfaces resulted in higher SBS means than the use of the same products on 50SB surfaces (P<0.05). Conclusion: Sandblasting associated with the use of metal conditioners improves SBS of resin composites to cpTi. .

Susceptibility profile of a Brazilian yeast stock collection of Candida species isolated from subjects with Candida-associated denture stomatitis with or without diabetes.

OBJECTIVE: This study investigated the susceptibility of 198 clinical isolates of Candida species against caspofungin, amphotericin B, itraconazole, and fluconazole. STUDY DESIGN: Suspensions of the microorganisms were spread on Roswell Park Memorial Institute (RPMI) agar plates. Etest strips were placed on the plates, and the minimal inhibitory concentration (MIC) was read after incubation (48 h at 37 °C). Data were analyzed by a factorial analysis of variance and a 2 × 2 post hoc test (α = .05). RESULTS: C glabrata showed the highest MIC values (P < .001) against caspofungin, itraconazole, and fluconazole. For amphotericin B, the MIC values of C tropicalis and C glabrata (P = .0521) were higher than those of C albicans (P < .001). Itraconazole was the least effective antifungal; 93.3% of the C glabrata isolates, 3.3% of the C albicans, and 1.3% of the C tropicalis were resistant. All microorganisms were susceptible to caspofungin and amphotericin B. CONCLUSIONS: Caspofungin and amphotericin B should be recommended as an effective alternative for the management of oral Candida infections when treatment with topical or other systemic drugs has definitely failed.

Eradication of a Mature Methicillin-Resistant Staphylococcus aureus (MRSA) Biofilm From Acrylic Surfaces

Methicillin-resistant Staphylococcus aureus (MRSA) can grow as structured biofilm in different surfaces, including oral mucosa and denture surfaces. Such biofilms can be released into the oral fluids and aspirated, causing systemic infections such as aspiration pneumonia. This study evaluated the efficacy of two disinfectant solutions and microwave irradiation in disinfecting acrylic specimens contaminated with MRSA biofilm. Thirty-six acrylic specimens were made, sterilized and contaminated with MRSA (107 cfu/mL). After incubation (37 °C/48 h), the specimens were divided into 4 groups: not disinfected (positive control); soaking in 1% sodium hypochlorite for 10 min; soaking in 2% chlorhexidine gluconate for 10 min; and irradiating by microwave for 3 min at 650 W. The viability of cells was evaluated by XTT reduction method. All specimens from the positive control group showed biofilm formation after 48 h incubation. The mean absorbance value of the control specimens was 1.58 (OD at 492 nm). No evidence of biofilm formation was observed on specimens after the disinfection methods. Disinfection by soaking in 1% sodium hypochlorite and 2% chlorhexidine gluconate and irradiating by microwaves resulted in 100% reduction of MRSA biofilm metabolism. The use of chemical solutions and microwave irradiation was shown to be effective for eradicating mature MRSA biofilms on acrylic resin specimens.

Staphylococcus aureus resistente à meticilina (MRSA, do inglês methicillin-resistant Staphylococcus aureus) pode crescer como biofilme estruturado em diferentes superfícies, incluindo mucosa bucal e superfícies de próteses. Estes biofilmes podem se dispersar nos fluidos orais e ser aspirados, causando infecções sistêmicas, como a pneumonia aspirativa. Este estudo avaliou a eficácia de duas soluções desinfetantes e irradiação por microondas na desinfecção de corpos-de-prova acrílicos contaminados com biofilme de MRSA. Trinta e seis espécimes de resina acrílica foram fabricados, esterilizados e contaminados com MRSA (107 ufc/mL). Após a incubação (37 °C/48 h), os espécimes foram divididos em quatro grupos: não desinfetados (controle positivo); imersos em hipoclorito de sódio 1% por 10 min; imersos em gluconato de clorexidina 2% por 10 min e irradiados por microondas durante 3 min a 650 W. A viabilidade das células foi avaliada pelo método de redução de XTT. Todos os espécimes do grupo controle apresentaram formação de biofilme após 48 h de incubação. O valor médio de absorbância destes espécimes foi de 1.58 (OD a 492 nm). Nenhuma evidência de formação de biofilme foi observada em todas as amostras desinfetadas. A desinfecção em hipoclorito de sódio 1%, gluconato de clorexidina 2% e irradiação em microondas resultou em 100% de redução do metabolismo do biofilme de MRSA. O uso de soluções químicas e irradiação em microondas mostrou-se eficaz na eliminação do biofilme maduro de MRSA sobre corpos-de-prova de resina acrílica.

Effect of thermal cycling on denture base and autopolymerizing reline resins.

OBJECTIVE: This study evaluated the fracture toughness (FT) of denture base and autopolymerizing reline resins, with and without thermocycling (T). MATERIAL AND METHODS: Specimens of each material (denture base acrylic resin - Lucitone 550 - L; autopolymerizing reline resins - Ufi Gel Hard-UH, Tokuyama Rebase II-TR, New Truliner-NT and Kooliner-K), were produced, notched and divided into two groups (n=10): CG (control group of autopolymerizing reline resins and L): FT tests were performed after polymerization; TG (thermocycled group): FT tests were performed after T (5°C and 55°C for 5,000 cycles). RESULTS: Results (MPa.m1/2) were analyzed by two-way ANOVA and Tukey's test (p=0.05). L exhibited the highest FT mean values in both groups (CG - 2.33; TG - 2.17). For the CG groups, NT showed the highest FT (1.64) among the autopolymerizing reline resins, and K the lowest (1.04). After T, when the autopolymerizing reline resins were compared, a statistically significant difference in FT was found only between the NT (1.46) and TR (1.00). CONCLUSIONS: Thermocycling increased the FT of K and did not influence the FT of L, UH, TR and NT.