Titanium Dioxide and Polyethylmethacrylate electrospun nanofibers: assessing the technique parameters and morphological characterization / Nanofibras eletrofiadas de dióxido de titânio e polietilmetacrilato: avaliação dos parâmetros da técnica e caracterização morfológica

This work studied the synthetization and morphological characterization of Polyethylmethacrylate (PEMA) nanofibers (NFs) containing titanium dioxide (TiO2) produced by the electrospinning technique. The solution to produce the nanofibers was prepared by dissolving 2.5g PEMA in 6.75mL of 1.1.2.2- tetrachloroethane and 3.375mL of dimethylformamide (DMF), and 0.405g of TiO2 was added to the solution. The nanofiber production used different distances between the tip of the needle to the collector (10, 12 and 15 cm) and two flow rates (0.05 mLh-1 and 0.08 mLh-1) were employed, while the applied voltage was 17kV. The NF morphology was analyzed by Scanning Electron Microscopy (SEM) and Image J software. We used Fourier Infrared Spectroscopy (FTIR) and Energy Dispersive X-Ray Spectroscopy (EDS) to evaluate the structural properties. All parameters were effective in the NF production, however it was shown that the distance of 12 cm produced the best NFs. The mean diameters showed no statistically significant difference between the samples. The FTIR analysis showed characteristic peaks of PEMA and TiO2 . It was concluded that the employed method was efficient for NF production containing PEMA and TiO2 , and the morphological characteristics of the NFs were influenced by the voltage and distance. (AU)

O presente trabalho estudou a sintetização e a caracterização morfologica de nanofibras (NFs) de polietilmetacrilato (PEMA) contendo dióxido de titânio (TiO2) produzidas pela técnica da eletrofiação. A solução para o preparo das nanofibras utilizou 2,5 g de PEMA dissolvidos em 6,75 mL de 1,1,2,2 - tetracloroetano (TCE) e 3,337 mL de dimetilformamida (DMF), em sequência foi adicionado 0, 405g de TiO2 à solução. Para eletrofiação, o equipamento foi constituído por uma fonte de alta tensão, uma seringa plástica com agulha de ponta reta e as NFs obtidas foram coletadas em anteparo metálico a 10, 12 e 15 cm de distância da ponta da agulha. A tensão aplicada foi de 17 kV e o fluxo de ejecção variou de 0.05 mLh-1 e 0.08 mLh1. O diâmetro e a morfologia das NFs foram avaliados por meio de Microscopia Eletrônica de Varredura (MEV) e pelo software Image J. A Espectroscopia por Transformada de Fourier (FTIR) e a Spectroscopia por energia dispersiva de raios X (EDS) avaliaram as propriedades estruturais. A análise morfológica das micrografias mostrou que a distância de 12cm da ponta da agulha até o coletor produziu as melhores NFs. O FTIR demonstrou picos característicos de PEMA e TiO2 . Diante dos resultados obtidos podemos concluir que o método empregado foi eficiente para a produção de NFs contendo PEMA e TiO2 e a variação da tensão e distancia influenciaram na morfologias das NFs.(AU)

Photodynamic inactivation of a multispecies biofilm using curcumin and LED light.

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.

Implantodontia guiada no tratamento estético-reabilitador de alto desempenho: qualidade e agilidade / Guided implantology in high performance rehabilitation aesthetic treatment: quality and speed

O objetivo deste estudo foi relatar um caso clínico no qual foi utilizado o sistema KEA-TECH, para planejamento e confecção do guia tomográfi co/cirúrgico na colocação de implante cone-morse com carga imediata. Foi proposta ao paciente (sexo masculino, 69 anos), com fratura radicular do elemento 11, a utilização da coroa natural remanescente como elemento provisório imediato. Pôde-se concluir que o planejamento adequado garante sucesso na reabilitação com implantes em áreas estéticas. Além disso, a utilização do sistema KEA-TECH proporciona facilidade e rapidez nos procedimentos clínicos.

The aim of this study was to report a clinical case where the KEA-TECH system was used to plan the tomographic/surgical guide and place a morse cone implant for immediate loading. The male, 69 years-old patient presented a root fracture at tooth 11, and his natural crown was used as a provisional immediate restoration. It was demonstrated that the adequate planning guarantees the success of implant rehabilitation in esthetic areas. Besides, the use of the KEA-TECH system allows for an easier and speed procedure at the daily clinics.

Photodynamic inactivation of a multispecies biofilm using Photodithazine(®) and LED light after one and three successive applications.

In this investigation, the effectiveness of successive applications of antimicrobial photodynamic inactivation (API) mediated by Photodithazine(®) (PDZ) and LED light was evaluated against a multispecies biofilm formed by Candida albicans, Candida glabrata, and Streptococcus mutans on denture base acrylic resin. Standard cell suspensions (bacteria and yeast) were inoculated on acrylic resin samples, and the biofilm was grown for 48 h (37 °C/75 rpm). API was performed by the administration of PDZ (175 and 200 mg/L) and exposure to 37.5 J/cm(2) of LED light (660 nm). Additional samples were treated with PDZ or LED light only. Untreated control samples were not submitted to light or PDZ. The conditions described were applied once or in three consecutive applications for all groups. Cell viability was determined by colony counts (CFU/mL), metabolic activity, total biomass, and confocal laser scanning microscopy (CLSM). Data were analyzed by a nonparametric two-way ANOVA and Tukey tests (α = 0.05). The results obtained demonstrated a significant effect (p < 0.05) of number of applications and treatment groups for CFU/mL, and S. mutans showed the highest susceptibility to API. The metabolic activity of the multispecies biofilm was significantly reduced (p < 0.05) after API for both numbers of applications, which were also significantly different (p < 0.05) between them. The total biomass of the biofilm was significantly different (p < 0.05) only between groups submitted to one and three API applications. CLSM showed a visual increase of dead cells after API. API-mediated PDZ was effective in reducing the cell viability of multispecies biofilm. Three consecutive applications of API were more effective for reducing the cell viability and the total biomass of multispecies biofilm.

An alternative technique for fabrication of frameworks in an immediate loading implant fixed mandibular prosthesis.

The oral rehabilitation of edentulous patients with immediate loading has become a safe procedure with high predictability. The success is related to immediate fabrication of a passive fit framework to attach the implants. Based on these considerations, this case report shows an alternative technique for mandibular rehabilitation using implants immediately loaded, where the framework was fabricated using cylinders with internal reinforcement and precast pieces, electrowelding, and conventional welding providing esthetics and function to the patient in a short period of time.

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.

A clinical report of an oral lichen planus associated to epidermoid carcinoma in contact with metallic restorations.

The aim of this study was to relate the clinical case of a patient with oral lichen planus (OLP) and a history of epidermoid carcinoma associated with metallic restorations. The etiology of OLP is a mucocutaneous disease, which is poorly understood. Studies point to the potential of malignant transformation of OLP and its association with metallic restorations. The metallic restorations were replaced by crowns with a ceramic covering associated and osseointegrated implants in the edentulous areas. About 1 year later, it was observed a bilateral regression of the tongue lesions. The replacement of metallic restorations can contribute to improvement of OLP.

Estudo da eficácia da terapia fotodinâmica, mediada pelos fotossensibilizadores Photodithazine® e Curcumina, sobre biofilmes multi-espécies formados por Streptococcus mutans, Candida albicans e Candida glabrata / Study of effectiveness of photodynamic therapy by Photodithazine and Curcumin photosensitizer against multispecies biofilms formed by Streptococcus mutans, Candida albicans and Candida glabrata

A capacidade de aderência dos micro-organismos a diferentes superfícies, a resistência a medicamentos, bem como a interação entre as espécies visam garantir a sobrevivência e a proliferação dos mesmos, resultando em menor susceptibilidade dos patógenos aos tratamentos e aos procedimentos de desinfecção. Este estudo teve como objetivo avaliar in vitro a eficácia da Terapia Fotodinâmica (PDT) mediada pelos fotossensibilizadores (FSs) Photodithazine® (PDZ) e Curcumina (Cur) sobre biofilmes multi-espécies compostos por Streptococcus mutans, Candida albicans e Candida glabrata. Para isso, o estudo foi divido em três partes: 1- avaliação do efeito fotodinâmico das diferentes concentrações de PDZ (100, 150, 175, 200 e 250mg/L) associada à luz LED (660nm/ 37,5J/cm2) na inativação de biofilme multi-espécies formado em fundo de placa de 96 orifícios; 2- avaliação do efeito fotodinâmico quando realizadas uma e três aplicações sucessivas de PDT, mediada por PDZ (175 e 200mg/L) e luz LED (660nm/ 37,5J/cm2) na inativação de biofilmes multi-espécies, formado sobre corposde-prova de resina acrílica. 3- avaliação do efeito fotodinâmico de diferentes concentrações do FS Cur (80, 100 e 120µM) associada à luz LED (455nm/37,5J/cm2) sobre biofilmes multi-espécies cultivados por diferentes períodos (24 e 48h) sobre corpos-de-prova de resina acrílica. Adicionalmente para cada condição avaliada foi verificado o efeito da aplicação isolada de cada concentração dos FSs PDZ e Cur em contato com o biofilme na ausência de luz (P+L-) e o efeito isolado da luz (P-L+). Além disso, foi realizado o grupo controle positivo, no qual o biofilme não esteve em contato com o FS e não foram iluminados com luz LED (P-L-). Após a aplicação dos tratamentos propostos, a viabilidade dos micro-organismos foi avaliada por meio da contagem de colônias (UFC/mL), teste do XTT, determinação da biomassa total e microscopia confocal de varredura laser (MCVL). Os resultados obtidos foram analisados por meio de ANOVA ou Kruskall-Wallis, seguidos dos testes de Tukey ou Dunn, respectivamente. Para o biofilme formado em fundo de placa as concentrações de 175 e 200mg/L de PDZ mostraram maior redução na quantificação de colônias (UFC/mL) e no metabolismo celular (XTT), entretanto não foi verificada redução da biomassa total. Na segunda parte do estudo, três aplicações sucessivas de PDT mediada por PDZ nas concentrações de 175 e 200 mg/L foram mais efetivas quando comparadas a uma aplicação na redução de S. mutans (quantificação de colônias), além da redução no metabolismo celular e biomassa total do biofilme multi-espécie. Na terceira parte do estudo foi verificado que a redução da viabilidade celular (UFC/mL) ocorreu para as três espécies microbianas no biofilme formado por 24 horas sobre corpos-de-prova. No entanto no biofilme de 48h apenas a C. glabrata e S. mutans tiveram redução da viabilidade celular. Além, disso a PDT mediada por Cur foi eficaz para reduzir o metabolismo celular e a biomassa total dos biofilmes formados por 24 e 48 horas. Adicionalmente, para todas as condições experimentais avaliadas após a aplicação da PDT, mediada por PDZ ou Cur, foi verificada maior redução da bactéria do que das cepas de Candida. Além disso, as imagens obtidas por MCVL mostraram que após a PDT, mediada por PDZ ou Cur, houve aumento visual do número de células marcadas com fluorescência vermelha, quando comparado ao grupo controle (P-L-), indicando a ocorrência de dano celular pela aplicação dos tratamentos propostos. Desta forma, pode ser sugerido que a PDT é um tratamento promissor para infecções bucais, sendo eficaz na redução de bactérias e fungos quando organizados em biofilme multi-espécies

The ability of adhesion of microrganisms to different surfaces, the drug resistance, as well as the interaction among the species help to ensure the survival and proliferation of these microrganisms and result in lower susceptibility of these pathogens to treatment and disinfection procedures. This study aimed to evaluate the in vitro efficacy of PDT mediated by photosensitizers (FSs) Photodithazine ® (PDZ) and Curcumin (Cur) against multispecies biofilms formed by Candida albicans, Candida glabrata and Streptococcus mutans. This study was divided into three parts: 1. evaluation of the effect of photodynamic therapy of different concentrations of PDZ (100, 150, 175, 200 and 250mg / L) associated with the LED light (660 nm / 37.5 J/cm2) in the inactivation of multspecies biofilms formed in 96-well microtiter plates; 2. evaluation of the photodynamic effect of one PDT applications only and three successive PDT applications mediated by PDZ (175 and 200 mg / L) and LED light (660 nm / 37.5 J/cm2 ) in the inactivation of multispecies biofilms, formed on acrylic resin samples; 3. evaluation of the photodynamic effect of different concentrations of Cur FS (80, 100, and 120µM) associated with LED light (455nm / 37.5 J/cm2 ) against multispecies biofilms grown during different periods (24 and 48h) on acrylic resin samples. Additional samples were treated either with FSs (PDZ or Cur) (P+L-) or LED light (P-L+) only. Positive control samples had neither light nor FSs (PDZ or Cur) (P-L-). After applying the proposed treatments, the viability of microrganisms was assessed by Colony Count (CFU / mL), the XTT assay, determination of the total biomass (CV) and confocal laser scanning microscopy (CLSM).The results were analyzed using ANOVA or Kruskal-Wallis test followed by Tukey or Dunn, respectively. For the biofilm formed in 96-well plate, the concentrations of 175 and 200mg/L showed greater reduction in cell viability (CFU/mL) and cell metabolism (XTT), but a reduction in total biomass was not observed. In the second part of the study, three successive applications of PDT mediated by PDZ concentrations of 175 and 200 mg/L showed higher microbial reduction of multispecies biofilm formed on acrylic resin samples than one application for all the proposed tests. In the third part of the study, it was found that the multispecies biofilm formed in 24 hours on acrylic resin sample was more sensitive to PDT than the 48 hours biofilm. After application of PDT mediated by PDZ or Cur, there was a greater reduction in bacteria than the Candida strains for all the test conditions mentioned. Furthermore, the images obtained by CLSM after PDT, mediated by PDZ or Cur, showed that there was an increase visual in the number of cells with red fluorescence when compared to the control group (P-L-), suggesting that there was cell damage through the application of these treatments. Thus, it can be suggested that PDT is a promising treatment for oral infections and is effective in reducing bacteria and fungi when associated in multispecies biofilm

Effect of water storage and heat treatment on the cytotoxicity of soft liners.

OBJECTIVE: To evaluate the effect of water storage time on the cytotoxicity of soft liners. METHODS: Sample discs of soft liners Dentusoft, Dentuflex, Trusoft, Ufi-Gel-P and denture base acrylic resin Lucitone-550 were prepared and divided into four groups: GN: No treatment, G24: Stored in water at 37°C for 24 h; G48: Stored in water at 37°C for 48 h, GHW: Immersed in water at 55°C for 10 min. To analyse the cytotoxic effect, three samples of each group were placed in tubes with Dubelcco's Modified Eagle Mediums and incubated at 37°C for 24 h. During this period, the toxic substances were leached to the culture medium. The cytotoxicity was analysed quantitatively by the incorporation of radioactivity (3)H-thymidine checking the number of viable cells (synthesis of DNA). The data were statistically analysed using two-way anova and Tukey's honestly significant difference tests (α = 0.05). RESULTS: Treatments did not reduce the cytotoxicity effect of the soft liners (p > 0.05). It was found that Ufi-Gel-P had a non-cytotoxic effect, Trusoft had a slightly cytotoxic effect, Dentuflex had a moderated cytotoxic effect, Dentusoft alternated between slightly and non-cytotoxic effect, and Lucitone-550 had non-cytotoxic effect when stored in water for 48 h. CONCLUSION: The effect of water storage and the heat treatment did not reduce the cytotoxicity of the soft liners.