Investigation of the effect of indirect pulp capping materials on dentin mineral density

Aim: To evaluate the potential of inducing mineral density changes of indirect pulp capping materials applied to demineralized dentin. Methods: A total of 50 cavities were prepared, 5 in each tooth, in extracted ten molars without caries, impacted or semi-embedded. The cavities were scanned by microcomputed tomography (µ-CT) after creating artificial caries by microcosm method (pre-treatment). Each cavity was subjected to one of 5 different experimental conditions: control (dental wax), conventional glass ionomer cement (Fuji IX GP Extra), resin-modified calcium silicate (TheraCal LC), resin-modified calcium hydroxide (Ultra-Blend Plus), MTA (MM-MTA) and the samples were kept under intrapulpal pressure using simulated body fluid for 45 days. Then, the second µ-CT scan was performed (post-treatment), and the change in dentin mineral density was calculated. Afterward, elemental mapping was performed on the dentinal surfaces adjacent to the pulp capping agents of 5 randomly selected samples using energy dispersive X-ray spectroscopy (EDS) apparatus attached to a scanning electron microscope (SEM). The Ca/P ratio by weight was calculated. Friedman test and Wilcoxon Signed Ranks test were used to analyze the data. Results: There was a significant increase in mineral density values of demineralized dentin after treatment for all material groups (p<0.05). Resin-modified calcium silicate had similar efficacy to MTA and conventional glass ionomer cement, but was superior to resin-modified calcium hydroxide in increasing the mineral density values of demineralized dentin. Conclusions: Demineralized dentin tissue that is still repairable can be effectively preserved using materials with remineralization capability

The ion partition detected in homeopathically manufactured medicine cuprum metallicum and controls

Homeopathy is highly controversial. The main reason for this is its use of very highly dilute medicines (high homeopathic potencies, HHP), diluted beyond the Avogadro/Loschmidt limit. Research using Nano Tracking Analysis has demonstrated the presence of particles in HHPs. This study aims to verify the results of a previous publication that identified the ionic composition of these particles in all dilutions. We used Scanning Electron Microscopy & Energy Dispersive X-Ray Spectroscopy (SEM-EDX) to examine dilutions of a commonly used homeopathic medicine, an insoluble metal, Cuprum metallicum, for the presence of particles (NPs). The homeopathic medicines tested were specially prepared according to the European pharmacopoeia standards. We compared the homeopathic dilutions/dynamizations of copper with simple dilutions and dynamized lactose controls. We observed an ionic diversity common to all preparations including HHPs but also significant differences in the relative quantity of each ion between manufacturing lines of homeopathic copper and lactose controls. The probability that the observed differences could have occurred chance alone (especially above Avogadro limit) can be rejected at p < 0.001. The essential component of these homeopathic medicines is sodium hydrogen carbonate, modulated by some other elements and by its quantity, size and shape. Homeopathic medicines made of Cuprum metallicum do contain material with a specific ionic composition even in HHPs diluted beyond the Avogadro/Loschmidt limit. This specificity can be attributed to the manufacturing process. This material demonstrates that the step-by-step process (dynamized or not) does not match the theoretical expectations of a dilution process. The starting material and dilution/dynamization method influences the nature of these NPs. Further measurements are needed on other raw materials using the same controls (solvent and simply diluted manufacturing lines) to support these findings. The role of sodium bicarbonate must be carefully studied in the future.

Evaluación de la mineralización en mandíbula y diente de trucha arcoíris (Oncorhynchus mykiss) mediante microscopía electrónica de barrido de presión variable acoplada a detector de espectroscopía de rayos X de energía dispersiva / Evaluation of mineralization in jaw and teeth of rainbow trout (Oncorhynchus mykiss) using variable pressure scanning electron microscopy coupled to energy-dispersive X-ray spectroscopy detector

RESUMEN: En salmonicultura se utilizan imágenes de rayos X, para evaluar la columna vertebral y las aletas, pero estas no permiten cuantificar los minerales que constituyen el hueso, para esto se utilizan otras técnicas que son destructivas. La Microscopía Electrónica de Barrido de presión variable (VP SEM) acoplada al detector espectroscopia de rayos X de energía dispersiva (EDX) acoplado, nos permite analizar la microestructura y a la vez determinar elementos químicos, porcentaje y distribución presentes en puntos específicos en una muestra. Se utilizaron 5 truchas control y 5 con deformidad mandibular, de agua dulce en etapa de smolt, se analizó la estructura y mineralización del hueso, se eligieron en promedio 6 puntos de cuantificación por región de interés y se analizaron mediante Microscopía Electrónica de Barrido (VP SEM-EDX). Los datos obtenidos muestran porcentaje en masa de Ca promedio en hueso articular de truchas fueron de 8.07 % y de 14.48 % en truchas con deformidad mandibular y control respectivamente y el porcentaje en masa promedio de P es de 4.07 % y 7.60 %, en truchas con deformidad mandibular y control respectivamente. Se identificó además otros elementos presentes en la muestra como Mg, Na, C, O, N, S, F, Zn, Al y Fe, con especial interés en el aumento de carbono en las muestras analizadas con deformidad mandibular y la presencia de aluminio en todas las muestras. La Técnica de VP SEM-EDX, permite evaluar de forma directa, sin destrucción de la muestra y con una preparación mínima de la muestra. En el hueso, la aplicación más frecuente de SEM-EDX es la medición del contenido de Ca y P y la relación que existe entre estos elementos Ca/P, en la muestra. Paralelamente la técnica nos permite la detección de otros microelementos provenientes del agua o de la alimentación y que eventualmente pueden provocar alteraciones en los peces, confirmando la hipótesis que el microanálisis elemental tiene utilidad para la salmonicultura.

SUMMARY: In salmon farming systems, X-ray images are used to evaluate the spine and fins, but these do not allow quantifying the minerals that make up the bone, for different techniques that are destructive are used. Variable Pressure Scanning Electron Microscopy (VP SEM) coupled to an Energy Dispersive X-ray spectroscopy detector (EDX), allows us to analyze the microstructure and at the same time determine chemical elements, percentages, and distribution present at specific points in a sample. Five control and five jaw deformity trout, from freshwater and in the smolt stage were used. The structure and mineralization of the bone were analyzed, an average six quantification points were chosen per region of interest (ROI) and then they were analyzed by Scanning Electron Microscopy (VP SEM-EDX). The data obtained have shown the average mass percentage of calcium in trout joint bone was 8.07 % and 14.48 % in jaw deformity and control trout, respectively; and the average mass percentage of phosphorus is 4.07 % and 7.60 %, in jaw deformity and control trout, respectively. Other elements present in the sample were also identified, such as magnesium, sodium, carbon, oxygen, nitrogen, sulphur, fluorine, zinc, aluminium, and iron, with special interest the increase of carbon in the analyzed samples with mandibular deformity and the presence of aluminum in all samples. The VP SEM-EDX Technique allows direct evaluation, without destruction of the sample and with minimal sample preparation. In bone, the most frequent application of SEM-EDX is the measurement of the content of calcium (Ca) and phosphorus (P) and the relationship that exists between these elements, calcium/phosphorus (Ca/P), in the sample. At the same time, the technique allows us to detect other microelements from water or food that can eventually cause alterations in fish, confirming the hypothesis that elemental microanalysis is useful for salmon farming.

Caracterização mecânica, termodinâmica e química de fios CuNiTi ­ um estudo comparativo clínico e laboratorial / Mechanical, thermodynamic and chemical characterization of CuNiTi wires ­ a clinical and laboratory comparative study

Introdução: Os fios Copper Ni-Ti (CuNiTi) possuem indicações de uso clínico específicas, permanecendo no ambiente bucal por um longo período. Por esse motivo suas características mecânicas, termodinâmicas e estruturais devem ser preservadas durante todo o período de uso. Objetivos: Investigar se ocorrem alterações no comportamento mecânico, termodinâmico, estrutura e composição química superficial em fios CuNiTi 35°C submetidos ao envelhecimento in vivo (uso clínico) e in vitro (termociclagem), evidenciando as possíveis diferenças entre os métodos de envelhecimento. Material e Métodos: A amostra total foi constituída de 30 arcos pré-contornados 0.016", termodinâmicos com adição de cobre, e temperatura austenítica final (Af) de 35°C, da marca Ormco®. As análises destes fios resultaram em dois capítulos. Para o experimento clínico, 10 unidades de fios foram instaladas em 05 pacientes e permaneceram em meio bucal durante 30, 60 e 90 dias, e 05 fios foram analisados como recebidos (CR). A cada período, um hemiarco completo mais 1/3 (um terço) do hemiarco inferior direito foi retirado para análises. Para o experimento in vitro os 15 fios restantes foram submetidos à termociclagem para simulação do envelhecimento em ambiente oral durante 30 (600 ciclos), 60 (1200 ciclos) e 90 dias (1800 ciclos) com variação de temperatura entre 5°C e 55°C, com banhos de 90 segundos em cada temperatura, e transição de 15 segundos entre os banhos. Após cada período de envelhecimento in vivo e in vitro, os fios foram submetidos a um teste de padronização das suas dimensões através da medição dos diâmetros com paquímetro, Microscopia Eletrônica de Varredura (MEV), Espectrometria por Raios X Fluorescentes (FRX), ensaios de tração uniaxial e ensaio de Varredura Diferencial de Calorimetria (DSC). Resultados: No capítulo 1 a comparação entre os fios CR e os envelhecidos revelou que não houve diferença significativa entre os diâmetros das amostras, das forças obtidas ou mesmo das temperaturas Af, independentemente do tempo de permanência em boca. Foram encontrados predominantemente Ni, Ti, Cu e Al nas amostras, além de outros elementos químicos em concentrações variadas. No capítulo 2 não houve diferença significativa entre os diâmetros das amostras, das forças obtidas ou mesmo das temperaturas Af entre as amostras, independentemente do tempo ou do método de envelhecimento. Conclusão: As análises laboratoriais dos fios envelhecidos in vivo e in vitro foram comparadas, evidenciando que as características mecânicas, termodinâmicas e químicas dos fios permanecem estáveis mesmo até 90 dias de uso clínico ou 1800 ciclos de termociclagem. O método de envelhecimento in vitro se mostra uma alternativa viável para a análise destes parâmetros, em substituição aos métodos in vivo (AU).

Introduction: Copper Ni-Ti wires (CuNiTi) have specific indications for clinical use, remaining in the oral environment for a long period. For this reason, their mechanical, thermodynamic and structural characteristics must be preserved throughout the period of use of these materials. Objectives: To investigate whether there are changes in the mechanical, thermodynamic, structure and surface chemical composition of CuNiTi 35°C wires subjected to in vivo aging (clinical use) and in vitro (thermocycling), highlighting the possible differences between the aging methods. Material and Methods: The total sample was obtained from 30 pre-contoured Ormco® 0.016 thermodynamic archwires with copper addition and austenitic final temperature (Af) of 35°C. The analysis of these archwires resulted in two articles. For the clinical experiment, 10 units of wires were installed in 05 patients and remained in the oral environment for 30, 60 and 90 days, and 05 wires were analyzed as received. At each period, a complete hemiarch plus 1/3 of the right lower hemiarch was removed for analysis. For the in vitro experiment, the 15 remaining wires underwent thermocycling to simulate the aging of the oral environment for 30 (600 cycles), 60 (1200 cycles) and 90 days (1800 cycles) with a temperature range between 5°C and 55°C, with 90 second baths at each temperature, and 15 second transition between baths. After each in vivo and in vitro aging period, the wires underwent to a standardization test of their dimensions, by defining the diameters with a caliper, Scanning Electron Microscopy (SEM), Fluorescent X-Ray Spectrometry (FRX), tests of Uniaxial traction and Differential Scanning Calorimetry (DSC) test. Results: In chapter 1, the comparison between CR and aged wires revealed that there was no significant difference between the sample diameters, the forces obtained or even the temperatures Af, regardless the time spent in the mouth. Predominantly Ni, Ti, Cu and Al were found in the samples, in addition to other chemical elements in different concentrations. In chapter 2 there was no significant difference between the diameters of the samples, the forces obtained or even the temperatures Af between the samples, regardless of time or aging method. Conclusion: The comparison of the laboratoral analyzes of the archwires aged in vivo and in vitro showed that the mechanical, thermodynamic and the surface chemical characteristics were stable, even up to 90 days of clinical use or 1800 thermocycling cycles. The in vitro aging method is a viable alternative for the analysis of these parameters, replacing the in vivo methods (AU).

Effect of the polishing procedure and surface sealant application on fluoride release / Efeito do procedimento de polimento e aplicação superficial de selante na liberação de flúor

Objectives: This study aimed to assess the effect of the polishing procedure and surface sealant application on the fluoride release of restorative materials. Material and Methods: The groups were consisted of using five different restorative materials were employed: Beautifil II, GCP Glass Fill, Amalgomer CR, Zirconomer and Fuji IX GP. 30 disk-shaped specimens (8x2 mm) were prepared from each material. Each group was subdivided into three groups considering finishing procedures: Mylar strip, polishing with Super-Snap discs, G-Coat Plus application after polishing with Super-Snap discs. The amount of fluoride released into distilled water was measured using a fluoride ion-selective electrode and ion analyzer after 24 hours, followed by measurement on days 3, 7, 15, 21, and 28. Surface analysis of the materials was performed with SEM (Scanning Electron Microscopy) and EDS (Energy Dispersive X-ray Spectroscopy). The data were statistically analyzed using two-way repeated measure ANOVA and LSD test (p=0.05). Results: The highest amount of fluoride released was measured after the first 24 h for all materials. Beautifil II released less fluoride than other materials in all measurement periods (p<0.05). After polishing, the amount of fluoride released from all materials except Beautifil II increased (p<0.05). The application of G-Coat Plus did not impact the amount of fluoride release of any materials (p>0.05). EDS analysis showed the most percentage of oxygen in all materials. Conclusion: The polishing procedure might induce an increase in fluoride release of glass ionomer-based materials, and the application of G-Coat Plus cannot affect the amount of fluoride release. (AU)

Objetivos: Este estudo teve como objetivo avaliar o efeito do procedimento de polimento e aplicação de selante superficial na liberação de flúor de materiais restauradores. Material e Métodos: Os grupos consistiram na utilização de cinco materiais restauradores diferentes: Beautifil II, GCP Glass Fill, Amalgomer CR, Zirconomer e Fuji IX GP. Trinta espécimes em forma de disco (8x2 mm) foram preparados a partir de cada material. Cada grupo foi subdividido em três grupos considerando os procedimentos de acabamento: tira Mylar, polimento com discos Super-Snap, aplicação de G-Coat Plus após polimento com discos Super-Snap. A quantidade de flúor liberada na água destilada foi medida usando um eletrodo íon-seletivo de fluoreto e analisador de íons após 24 horas, seguido pela medição nos dias 3, 7, 15, 21 e 28. A análise da superfície dos materiais foi realizada com MEV (Microscopia Eletrônica de Varredura) e EDS (Espectroscopia de Energia Dispersiva de Raios-X). Os dados foram analisados estatisticamente usando ANOVA de dois fatores com medidas repetidas e teste LSD (p = 0,05). Resultados: A maior quantidade de flúor liberado foi medida após as primeiras 24 horas para todos os materiais. O Beautifil II liberou menos flúor do que outros materiais em todos os períodos avaliados (p <0,05). Após o polimento, a quantidade de flúor liberada de todos os materiais, exceto Beautifil II, aumentou (p <0,05). A aplicação de G-Coat Plus não afetou a quantidade de liberação de flúor de nenhum material (p> 0,05). A análise por EDS revelou a maior porcentagem de oxigênio em todos os materiais. Conclusão: O procedimento de polimento pode induzir um aumento na liberação de flúor de materiais à base de ionômero de vidro, e a aplicação de G-Coat Plus não pode afetar a quantidade de liberação de flúor (AU)

Síntese e caracterização de ciclotrifosfato de sódio contendo cálcio e seu efeito na prevenção da erosão do esmalte in vitro / Synthesis and characterization of calcium-containing sodium cyclotriphosphate and its effect on preventing enamel erosion in vitro

O objetivo do presente estudo foi sintetizar e caracterizar ciclotrifosfato de sódio (NaTMP) contendo cálcio, e verificar seu efeito utilizando modelo de lesões iniciais de erosão do esmalte. Os ciclotrifosfatos contendo cálcio (CaNaTMP) foram sintetizados utilizando coluna para cromatografia e adição de sobrenadante de solução contendo hidróxido de cálcio e analisados por meio de microscopia eletrônica de varredura e espectroscopia de raios-X por dispersão de energia. Para determinar o efeito sobre lesões erosivas iniciais, blocos de esmalte bovino sadios (n=96) foram selecionados por dureza de superfície inicial e divididos em 8 grupos experimentais (12 blocos/grupo): controle (água deionizada), 0,24% NaF (1100 ppm F), 0,25%, 0,5% e 1% de NaTMP e CaNaTMP nas mesmas concentrações. Os blocos de esmalte foram imersos em 4 mL das soluções experimentais durante 2 minutos, seguidos por 4 desafios erosivos (ácido cítrico, 0,75%, pH 3,5, por 1 minuto, sob agitação). A porcentagem de perda da dureza de superfície (%SH) foi calculada após cada desafio ácido. Os dados foram submetidos à análise de variância de medidas repetidas a dois critérios, seguida pelo teste de Tukey (p< 0,05). O processo de síntese levou a substituição de átomos de Na por átomos de Ca e as partículas apresentaram tamanhos homogêneos. As soluções contendo 0,25%, 0,5% e 1% CaNaTMP apresentaram menor %SH quando comparadas as suas contrapartes sem cálcio (p< 0,001), após os quatro desafios erosivos. Quando comparado a solução contendo 1100 ppm F, as soluções 0,5% e 1% CaNaTMP promoveram redução na perda de dureza (p< 0,001). Concluiu-se que soluções contendo CaNaTMP promoveram efeitos protetores superiores em comparação ao grupo 1100 ppm F sobre lesões iniciais do esmalte(AU)

The objective of the present study was to synthesize and characterize sodium cyclotriphosphate (NaTMP) containing calcium and verify its effect using an initial enamel erosion model. Cyclotriphosphate containing calcium (CaNaTMP) was synthesized using column chromatography, and addition of a solution with calcio hydroxide supernatant and analyzed by scanning electron microscopy and energydispersive X-ray spectroscopy. To determine the effect on enamel initial erosion, sound bovine enamel blocks (n=96) were selected by initial surface hardness and divided into to 8 experimental groups (12 blocks/group): control (deionized water), 0.24% NaF (1100 ppm F), 0.25%, 0.5% and 1% NaTMP and CaNaTMP at the same concentrations. The enamel blocks were immersed in 4 mL of the experimental solutions for 2 minutes followed by 4 erosive challenges (citric acid, 0.75%, pH 3.5, for 1 minute, under stirring). The percentage of surface hardness variation (%SH) was calculated after each acid challenge. Data were subjected to two-way repeated measures analysis of variance, followed by Tukey's test (p< 0.05). The synthesis process led to the replacement atoms of Na by atoms of Ca with particles having, homogeneous sizes. The solutions containing 0.25%, 0.5% and 1% CaNaTMP promoted lower %SH when compared to their counterparts without calcium (p< 0.001), after the four erosive challenges. When compared to the solution containing 1100 ppm F, the 0.5% and 1% CaNaTMP solutions were superior in reducing hardness loss (p< 0.001). It was concluded that solutions containing CaNaTMP led to superior protective effects compared to the 1100 ppm F group on initial enamel erosion(AU)

Effect of antioxidant agents after dental bleaching on luting of ceramic laminates / Efeito de agentes antioxidantes pós-clareamento na cimentação de laminados cerâmicos

O objetivo deste estudo in vitro foi avaliar o efeito da aplicação de agentes antioxidantes após o clareamento dentário e previamente à cimentação de laminados cerâmicos na estabilidade cromática do conjunto restaurador, assim como nas propriedades mecânicas de nanodureza (HIT), módulo de elasticidade (Eit*), grau de conversão, resistência de união e morfologia da interface adesiva. Ademais, a neutralização de peróxido de hidrogênio e a caracterização superficial do esmalte, como ângulo de contato, energia de superfície, energia livre total de interação, microscopia eletrônica de varredura e espectroscopia de energia dispersiva do substrato submetido à ação das soluções antioxidantes e do agente clareador também foram analisados. Duzentos e quarenta e dois blocos de esmalte dentário (7x8x0,6mm) foram utilizados para o processo de cimentação e distribuídos em grupos experimentais de acordo com os métodos de procedimentos (grupo não clareado, grupo clareado com Whiteness HP Maxx 35%), tipos de antioxidantes adotados (controle; ácido ascórbico 10% e α-tocoferol 10%) e períodos de cimentação (após 24 horas e 14 dias do processo de cimentação) (n = 22). Foi utilizado o sistema adesivo Tetric N Bond Universal e o cimento resinoso Variolink Esthetic LC (Ivoclar Vivadent) como agentes cimentantes. Os dados foram submetidos a testes estatísticos de normalidade e analisados por ANOVA e teste de Tukey (α = 0,05). Os dados da morfologia da interface adesiva, obtidas pela microscopia confocal a laser, foram submetidas ao teste Kappa inter-examinadores e os dados foram submetidos aos testes Kruskal-Wallis e Dunn (α = 0,05). Os resultados mostraram que, de modo geral, a utilização da solução antioxidante α-tocoferol 10% pós-clareamento no período mediato promoveu resultados satisfatórios com relação à estabilidade cromática do conjunto restaurador, assim como para as propriedades mecânicas, grau de conversão, resistência de união e morfologia da interface adesiva comparado ao grupo clareado sem associação dos agentes antioxidantes, tanto para o período mediato, quanto para o período de 14 dias (p< 0,05). A solução de αtocoferol 10% apresentou maiores valores de neutralização do peróxido de hidrogênio e maiores valores de molhabilidade do esmalte em relação aos grupos controle e ácido ascórbico (p< 0,05). A energia de superfície e energia livre total de interação do esmalte dentário foi significativamente influenciada pelo tratamento clareador (p< 0,05). Dessa forma, conclui-se que o emprego da solução antioxidante α-tocoferol 10% promoveu resultados promissores, sugerindo que o mesmo poderia ser utilizado mediatamente após o clareamento dental na cimentação de laminados cerâmicos(AU)

The aim of this in vitro study was to evaluate the effect of antioxidant agents application after tooth bleaching and prior to luting of ceramic veneers on color stability of the restorative set, as well as on mechanical properties of nanohardness (HIT), elastic modulus (Eit*), degree of conversion, bond strength and morphology of the adhesive interface. Furthermore, the hydrogen peroxide neutralization and surface characterization of enamel, such as contact angle, surface energy, total free energy of interaction, scanning electron microscopy and energy-dispersive spectroscopy of the substrate submitted to the action of antioxidant solutions and bleaching agent were also analyzed. Two hundred forty two dental enamel blocks (7 x 8 x 0.6 mm) were used for the luting process and distributed into experimental groups according to the procedure methods (unbleached group, bleached group with Whiteness HP Maxx 35%), types of antioxidants adopted (control; 10% ascorbic acid and 10% α-tocopherol) and the luting periods (24 hours and 14 days after the luting process) (n = 22). Tetric N Bond Universal adhesive system and Variolink Esthetic LC resin cement (Ivoclar Vivadent) were used as luting agents. Data were submitted to statistical tests of normality and analyzed by ANOVA and Tukey tests (α = 0.05). The adhesive interface morphology data, obtained by confocal laser microscopy, were submitted to the interexaminer Kappa test and the data were submitted to Kruskal-Wallis and Dunn´s tests (α = 0.05). The results showed that, in general, the use of 10% α-tocopherol antioxidant solution after bleaching in mediate period promoted satisfactory results regarding the color stability of the restorative set, as well as for the mechanical properties, degree of conversion, shear bond strength and adhesive interface morphology compared to the bleached group without antioxidant agents association, both for the mediate and 14-day period (P < 0.05). The 10% αtocopherol solution showed higher hydrogen peroxide neutralization values and higher enamel wettability values compared to the control and ascorbic acid groups (P < 0.05). Surface energy and total free energy of interaction of tooth enamel were significantly influenced by the bleaching treatment (P < 0.05). Thus, it is concluded that the use of 10% αtocopherol antioxidant solution promoted promising results, suggesting that it could be used mediately after tooth bleaching on luting of ceramic laminates(AU)

Preparation and characterization of naftifine-loaded poly(vinyl alcohol)/sodium alginate electrospun nanofibers

In this study, naftifine (a topical antifungal drug) loaded poly(vinyl) alcohol (PVA)/sodium alginate (SA) nanofibrous mats were prepared using the single-needle electrospinning technique. The produced nanofibers were crosslinked with glutaraldehyde (GTA) vapor. The morphology and diameter of the electrospun nanofibers were studied by scanning electron microscopy (SEM). SEM images showed the smoothness of the nanofibers and indicated that the fiber diameter increased with crosslinking and drug loading. Atomic force microscopy (AFM) images confirmed the uniform production of the scaffolds, and elemental mapping via energy dispersive X-ray spectroscopy (EDS) showed the uniform distribution of the drug within the nanofibers. An attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy study demonstrated that naftifine has sufficient secondary interactions with the polymer blend. The crosslinking treatment decreased the burst drug release effectively and the release mechanism followed Korsmeyer-Peppas Super Case-II transport. Overall, these findings suggest the potential use of naftifine-loaded PVA/SA nanofibers as a topical antifungal drug delivery system.

The effect of ionizing radiation on properties of fluoride-releasing restorative materials

Abstract The purpose of this study was to evaluate the effect of ionizing radiation from high energy X-ray on fluoride release, surface roughness, flexural strength, and surface chemical composition of the materials. The study groups comprised five different restorative materials: Beautifil II, GCP Glass Fill, Amalgomer CR, Zirconomer, and Fuji IX GP. Twenty disk-shaped specimens (8x2 mm) for fluoride release and 20 bar-shaped specimens (25 x 2x 2 mm) for flexural strength were prepared from each material. Each material group was divided into two subgroups: irradiated (IR) and non-irradiated (Non-IR). The specimens from IR groups were irradiated with 1.8 Gy/day for 39 days (total IR = 70.2 Gy). The amount of fluoride released into deionized water was measured using a fluoride ion-selective electrode and ion analyzer after 24 hours and on days 2, 3, 7, 15, 21, 28, 35, and 39 (n = 10). The flexural strength was evaluated using the three-point bending test (n = 10). After the period of measurement of fluoride release, seven specimens (n = 7) from each group were randomly selected to evaluate surface roughness using AFM and one specimen was randomly selected for the SEM and EDS analyses. Data were analyzed with two-way ANOVA and Tukey tests (p = 0.05). The irradiation significantly increased fluoride release and surface roughness for Amalgomer CR and Zirconomer groups (p < 0.05). No significant change in flexural strength of the materials was observed after irradiation (p > 0.05). The ionizing radiation altered the amount of fluoride release and surface roughness of only Amalgomer CR and Zirconomer. The effect could be related to the chemical compositions of materials.

Chemical and structural composition of black pigmented supragingival biofilm of bovines with periodontitis / Composição química e estrutural do biofilme supragengival pigmentado de bovinos com periodontite

Bovine periodontitis is a multifactorial disease primarily associated with a potentially pathogenic microbiota housed in the oral biofilm of animals. Biofilms are organized structures, in which the constituents coexist in symbiosis, already described as a predisposing factor to periodontitis in other species. The objective of the present study was to characterize the structure and chemical aspects of the bovine black pigmented supragingival biofilm using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS), respectively, and determine its relationship with bovine periodontitis. Eleven premolar teeth from different animals were evaluated; five non-pigmented samples and six samples with black pigmented biofilms were initially submitted to SEM, and three areas of these samples were selected for EDS. The structure of the pigmented biofilm was more complex and irregular because of a higher content of mineral elements. The semi-quantitative EDS data indicated an association of iron (p<0.014) and magnesium (p<0.001) with the occurrence of periodontitis, whereas carbon, phosphorus, calcium, manganese, sodium, and potassium were not associated with the disease. Carbon (p<0.039), manganese (p<0.007), and iron (p<0.015) were associated with pigmentation, whereas phosphorus, calcium, and magnesium were not associated with it. Spearman correlation test showed the relationships between calcium and phosphorus, and iron and silicon. The strong association of iron in the pigmented supragingival biofilm and with the occurrence of periodontitis suggests the presence of microorganisms that use this element in their metabolism and that are also associated with bovine periodontitis. This study suggests that the pigmented deposits in the crown of the teeth of cattle are an true biofilm with the deposition of iron, and it indicates that the presence of iron and magnesium in these formations may be involved in the metabolism of some microorganisms associated with the etiology of bovine periodontitis.(AU)

A periodontite bovina é uma infecção multifatorial associada primariamente à microbiota potencialmente patogênica presente no biofilme bucal. Biofilmes são estruturas organizadas, nas quais os constituintes convivem em simbiose, descritos em outras espécies como um fator predisponente à periodontite. O objetivo do presente estudo foi caracterizar estrutural e quimicamente o biofilme supragengival pigmentado de preto em bovinos, utilizando-se as técnicas de microscopia eletrônica de varredura (MEV) e espectroscopia de dispersão de energia (EDS), respectivamente, correlacionando os elementos identificados à ocorrência de periodontite e pigmentação. Foram avaliados 11 dentes primeiro-molares; cinco amostras sem pigmentação visível e seis amostras com biofilme pigmentado de preto, que foram submetidas inicialmente à MEV; posteriormente foram selecionadas três áreas aleatórias de cada dente para realização da EDS. A estrutura do biofilme pigmentado revelou formações irregulares e mais complexas, provavelmente devido ao maior acúmulo de elementos minerais. Os resultados semi-quantitativos da EDS apontaram associações entre a presença de ferro (p<0,014) e magnésio (p<0,001) com a ocorrência de periodontite. Carbono, fósforo, cálcio, manganês, sódio e potássio não apresentaram associação com a periodontite. Em relação à pigmentação, carbono (p<0,039), manganês (p<0,007) e ferro (p<0,015) foram os elementos estatisticamente significantes, enquanto fósforo, cálcio e magnésio não apresentaram associação com a pigmentação. O teste de correlação de Spearman demonstrou associações entre os elementos cálcio e fósforo, e ferro e silício. A forte associação do ferro presente no biofilme supragengival com a ocorrência de periodontite, sugere a presença de micro-organismos que utilizam este elemento em seu metabolismo e que possivelmente tenham envolvimento com o desenvolvimento da periodontite bovina. Os resultados inéditos do presente trabalho sugerem que os depósitos pigmentados que se formam na coroa dos dentes de bovinos são um biofilme verdadeiro com deposição de ferro, e indicam que a presença de ferro e magnésio nestas formações pode estar envolvida no metabolismo de alguns dos principais micro-organismos associados à etiologia da periodontite bovina.(AU)

Xpektrin, un simulador de espectros fácil de usar y ampliamente distribuible para radiología general / Xpektrin, an easy to use and highly distributable X-Ray spectra simulator in general radiography

Resumen: Se presenta una aplicación basada en Microsoft Excel llamada Xpektrin para el cálculo de dosis en radiología general. La aplicación permite simular espectros de rayos X en radiología general utilizando el modelo TASMICS a partir de mediciones del kerma en aire (Kair) y de la capa Hemirreductora (HVL). Tiene implementado el cálculo de magnitudes radiométricas y dosimétricas, como el kerma en aire en la superficie de entrada (Ke) y la dosis en piel (Dskin), en función de la elección arbitraria de los factores de exposición, el tipo y grosor de filtro, la distancia foco-piel y el tamaño de campo. Xpektrin fue validado con la herramienta computacional SPEKTR 3.0, utilizando mediciones de dosis y de HVL de tubos de rayos X de tres recintos hospitalarios. Se encontró buena correlación en ambas aplicaciones entre las mediciones experimentales y los valores calculados de HVL y con coeficientes de Pearson R² ≥ 0.99 en todos los casos. Sin embargo, se obtuvo mejor concordancia con los valores experimentales de HVL con Xpektrin (mediana de diferencias -0.43%, -0.04% y 0.01%) que con SPEKTR 3.0 (mediana de diferencias -3.31%, 0.10% y -7.85%), en particular para el tubo con mayor filtración. Xpektrin está optimizada para ser utilizada en los departamentos de radiología para la determinación de dosis de pacientes individuales en función de los parámetros utilizados durante la exposición, por lo que puede ser utilizada como parte de un sistema de registro dosimétrico o como apoyo para el establecimiento de niveles de referencia para diagnóstico (NRD), siendo particularmente útil en servicios con equipos sin registros automáticos de dosis. Además, debido a sus características de simulador, puede ser útil como herramienta pedagógica. El uso de Excel permite que sea altamente distribuible y fácil de usar, sin necesidad de conocimientos de programación.

Abstract: Xpektrin, an easy to use and highly distributable X-Ray Spectra Simulator in General Radiography. An application based on Microsoft Excel called Xpektrin is presented for dose calculation in general radiology. The application was developed to simulate X-ray spectra in general radiography using the TASMICS model. Using as inputs air kerma (Kair) and Half-value layer (HVL) measurements, Xpektrin allows the calculation of several radiometric and dosimetric quantities, such as the entrance surface air kerma (Ke) and the skin dose (Dskin), depending on the exposure factors, filter material type, filter thickness, focus-skin distance and field size. Xpektrin was validated against the Matlab toolkit SPEKTR 3.0, using dose and HVL measurements of X-ray tubes from three different hospitals. It was found good correlation in both applications between the experimental measurements and the calculated HVL and Kair values with Pearson coefficients R² ≥ 0.99 in all cases. However, experimental and calculated HVL have better agreement with Xpektrin (median percent difference -0.43%, -0.04% and 0.01%) than SPEKTR 3.0 (median percent difference -3.31%, 0.10% and -7.85%), particularly for the tube with greater filtration thickness. Xpektrin is optimized to be used in radiology departments for patient dose determination depending on the exposure parameters and may be used as part of a dosimetric record system or as a support for the determination of Diagnostic Reference Levels, which may be useful when no automatic dose records are available. In addition, due to its simulator characteristics, it can be useful as a pedagogical tool. Using Excel allows Xpektrin to be highly distributable and easy to use, without the need for programming skills.

Biologically Synthesized Silver Nanoparticles for Enhancing Tetracycline Activity Against Staphylococcus aureus and Klebsiella pneumoniae

Abstract Phytochemical content of plant extracts can be used effectively to reduce the metal ions to nanoparticles in one-step green synthesis process. In this study, six plant extracts were used for the synthesis of silver nanoparticles (AgNPs). Biologically synthesized AgNPs was characterized using UV-Vis Spectrophotometer, Field Emission Scanning Electron Microscope (FE-SEM), X-ray diffraction (XRD), Energy Dispersive X-ray spectroscopy (EDX) and Fourier Transform Infrared (FTIR) spectroscopy. The individual and combined effects of AgNPs and tetracycline against S. aureus and K. pneumoniae were assessed. Ginger, onion and sidr extracts supported AgNPs formation while arak, garlic and mint extracts failed to convert the silver ions to AgNPs. The present findings revealed significant differences between the tested plant extracts in supporting AgNPs synthesis. AgNPs synthesized by ginger showed the highest individual and combined activity against tested strains followed by AgNPs prepared by sidr then that synthesized by onion. AgNPs significantly enhanced tetracycline activity (p≤0.05) against S. aureus and K. pneumoniae. The results of this study demonstrated that the combination of tetracycline and biologically synthesized AgNPs presented a useful therapeutically method for the treatment of bacterial infection and counterattacking bacterial resistance.

Effect of a resin-modified glass-ionomer with calcium on enamel demineralization inhibition: an in vitro study

Abstract We assessed the effect of a new coating material based on resin-modified glass-ionomer with calcium (Ca) in inhibiting the demineralization of underlying and adjacent areas surrounding caries-like lesions in enamel. The measures used were surface hardness (SH) and cross-sectional hardness (CSH). Thirty-six bovine enamel specimens (3 × 6 × 2 mm) were randomly allocated into three groups (n = 12): No treatment (NT); resin-modified glass-ionomer with Ca (Clinpro XT Varnish, 3M ESPE) (CL), and fluoride varnish (Duraphat, Colgate) (DU). The specimens were subjected to alternated immersions in demineralizing (6 h) and remineralizing solutions (18 h) for 7 days. SH measurements were conducted at standard distances of 150, 300, and 450 µm from the treatment area. CSH evaluated the mean hardness profile over the depth of the enamel surface and at standard distances from the materials. The energy-dispersive X-ray spectroscopy analysis was conducted to evaluate the demineralization bands created on the sublayer by % of calcium (Ca), phosphorus (P), and fluoride (F). Ca/P weight ratio was also calculated. Based on SH and CSH measurements, there was no difference between groups at the distances 150 µm (p = 0.882), 300 µm (p = 0.995), and 450 µm (p = 0.998). Up to 50 µm depth (at 150 µm from the treatment area), CL showed better performance than DU ( p< 0.05). NT presented higher loss of Ca and P than CL and DU (p < 0.05). There was no significant difference in the % of F ion among the three groups. The new coating material was similar to F varnish in attenuating enamel demineralization.

Influência do tamoxifeno na remodelação óssea periimplantar / Influence of tamoxifen on periimplant bone remodeling

O propósito do presente estudo foi avaliar a remodelação óssea de implantes ósseointegrados instalados em tíbias de ratos modificados ou não sistemicamente pelo tamoxifeno. Foram utilizadas 72 ratas, os animais receberam ovariectomia bilateral, instalação dos implantes em tíbia bilateralmente e após 6 semanas,foram aleatoriamente distribuídas em dois grupos experimentais(n=36), Grupo SS: administração de solução salina e Grupo TAM: administração de citrato de tamoxifeno, via gavagem por todo o período experimenta. Doze animais de cada grupo foram eutanasiados aos 30, 60 e 90 dias após a administração da primeira dose das soluções, as tíbias direita e esquerda foram coletadas, e aleatóriamente processadas com desmineralização para as análises histológicas, imunoistoquímicas e para a análise de porcentagem de tecido ósseo neoformado(PTON) e sem desmineralização para análise do contato osso/implante(BIC) e para as análises de Microscopia Eletrônica de Varredura (MEV) e de Espectroscopia Dispersiva de Raio-x (EDS). Os dados obtidos foram submetidos à análise estatística (p< 0,05) em programa computacional especializado. Com relação ao contato osso implante, o grupo TAM, apresentou maior BIC em todos os períodos experimentais quando comparado com o grupo SS. O grupo TAM apresentou também maior PTON em todos os períodos experimentais quando comparado com o grupo SS. A análise histológica dos tecidos periimplantares mostrou que o grupo TAM apresentou características histológicas que se mostraram similares ao grupo controle, no entanto, com maior quantidade de tecido ósseo peri-implantar e menor quantidade de tecido conjuntivo . Nos padrões de marcação imunoistoquímica, quando comparado ao grupo SS, o grupo TAM apresentou maior imunomarcação para RUNX-2 e OCN, menor marcação para TRAP e não houve diferenças quanto a marcação de BMP-2/4. Em respeito a análise EDS o grupo tamoxifeno apresentou maior Fração de Ca/P em área regenerada em relação ao grupo SS todos os períodos experimentais. Comparado ao grupo ss, o grupo tamoxifeno mostrou na análise MEV uma superfície óssea periimplantar com maior presença de fibras de colágeno a partir do período de 30 dias, sendo mais evidente no período de 90 dias, enquanto no grupo SS a quantidade de fibras é mantida em um perfil mais baixo e decrescente. Dentro dos limites do presente estudo, pode-se concluir que o Tamoxifeno exerceu uma influência positiva na remodelação óssea periimplantar em implantes osseointegrados(AU)

The purpose of the present study was to evaluate the bone remodeling of osseointegrated implants installed in tibias of rats modified or not systemically modified by tamoxifen. Seventy-two female rats were used, the animals received bilateral ovariectomy, tibial implant placement bilaterally and after 6 weeks were randomly assigned to two experimental groups (n = 36). Group SS: received saline administration and Group TAM: received administration of tamoxifen citrate via gavage throughout the experimental period. Twelve animals from each group were euthanized at 30, 60 and 90 days after administration of the first dose of the solutions. The right and left tibias were collected, processed with demineralization for histológical, immunohistochemical and percentage analysis of neoformed bone tissue. (PTON) and without demineralization for bone / implant contact analysis (BIC) and for Scanning Electron Microscopy (SEM) and Xray Dispersive Spectroscopy (EDS). The data obtained were submitted to statistical analysis (p < 0.05) in a specialized computer program. With regard to implant bone contact, the TAM group presented higher BIC in all experimental periods when compared to the SS group. The TAM group also presented higher PTON in all experimental periods when compared to the SS group. Histológical analysis of periimplant tissues showed that the TAM group presented histológical characteristics that were similar to the control group, however, with a larger amount of peri-implant bone tissue and a smaller amount of connective tissue. In the immunohistochemical staining patterns, when compared to the SS group, the TAM group presented higher immunostaining for RUNX-2 and OCN, lower TRAP labeling and no differences regarding BMP-2/4 labeling. Regarding the EDS analysis, the tamoxifen group presented higher Ca / P fraction in regenerated área in relation to the SS group all experimental periods. Compared to the ss group, the tamoxifen group showed in the SEM analysis a periimplant bone surface with greater presence of collagen fibers from 30 days, being more evident over 90 days, while in the SS group the amount of fibers is maintained. in a lower and decreasing profile. Within the limits of the present study, it can be concluded that Tamoxifen had a positive influence on periimplant bone remodeling in osseointegrated implants(AU)

Effects of in-office bleaching agent combined with different desensitizing agents on enamel

Abstract Objective: To analyze color change, microhardness and chemical composition of enamel bleached with in-office bleaching agent with different desensitizing application protocols. Materials and Methods: One hundred and seventeen polished anterior human enamel surfaces were obtained and randomly divided into nine groups (n = 13). After recording initial color, microhardness and chemical composition, the bleaching treatments were performed as G1: Signal Professional White Now POWDER&LIQUID FAST 38% Hydrogen peroxide(S); G2: S+Flor Opal/0.5% fluoride ion(F); G3: S+GC Tooth Mousse/Casein Phosphopeptide-Amorphous Calcium Phosphate (CPP-ACP) paste(TM); G4: S+UltraEZ/3% potassium nitrate&0.11% fluoride(U); G5: S+Signal Professional SENSITIVE PHASE 1/30% Nano-Hydroxyapatite (n-HAP) suspension(SP); G6: S-F mixture; G7: S-TM mixture; G8: S-U mixture; G9: S-SP mixture. Color, microhardness and chemical composition measurements were repeated after 1 and 14 days. The percentage of microhardness loss (PML) was calculated 1 and 14 days after bleaching. Data were analyzed with ANOVA, Welch ANOVA, Tukey and Dunnett T3 tests (p<0.05). Results: Color change was observed in all groups. The highest ΔE was observed at G7 after 1 day, and ΔE at G8 was the highest after 14 days (p<0.05). A decrease in microhardness was observed in all groups except G6 and G7 after 1 day. The microhardness of all groups increased after 14 days in comparison with 1 day after bleaching (p>0.05). PML was observed in all groups except G6 and G7 after bleaching and none of the groups showed PML after 14 days. No significant changes were observed after bleaching at Ca and P levels and Ca/P ratios at 1 or 14 days after bleaching (p>0.05). F mass increased only in G2 and G6, 1 day after bleaching (p<0.05). Conclusions: The use of desensitizing agents containing fluoride, CPP-ACP, potassium nitrate or n-HAP after in-office bleaching or mixed in bleaching agent did not inhibit the bleaching effect. However, they all recovered microhardness of enamel 14 days after in-office bleaching.

Chemical and Microscopy Characterization of Trans-Endodontic Implants / Caracterización química y microscópica de implantes trans-endodónticos

Abstract Trans-endodontic implants are an artificial extension through root apex anchored in periradicular bone tissue. The aim is to improve the crown-root ratio and to provide stability to dental organ present. Zirconium oxide (ZrO2) is a material of great technological importance, having good natural color, high strength, high toughness, high chemical stability, does not suffer any corrosion, chemical and microbial resistance and excellent esthetic properties. Objective: The aim of this study was to evaluate chemical and microscopy of surface conditions of ZrO2 trans-endodontic implant. Materials and Methods: A blocks of ZrO2 were manufactured for produce trans-endodontic implants and divided in two groups: monoclinic and tetragonal phase. They were evaluated using Scanning Electroning Microscope (SEM), EnergyDispersive X-ray Spectroscopy (EDS), and Atomic Force Microscope (AFM) and Vickers Micro hardness. Results: The Monoclinic phase through AFM analysis showed roughness Ra = 0.320μm, whereas in the Tetragonal phase was 0.126μm, SEM/EDX indicated that the phases are not properly uniform and the addition of the Yttrium to favor the stabilization of the Tetragonal phase. The Vickers hardness analysis showed a value of 1500HV. Conclusion: The characterization of the surface of trans-endodontic zirconium oxide implants provides a guideline to know the surface characteristics of the material, since a greater roughness on the surface of the implant will favor the Osseo-integration capacity.

Resumen Los implantes trans-endodónticos son una extensión artificial a través del ápice radicular anclado en el tejido óseo periradicular. El objetivo es mejorar la relación corona-raíz y proporcionar estabilidad al órgano dental presente. El óxido de zirconio (ZrO2) es un material de gran importancia tecnológica, con buen color natural, alta resistencia, alta tenacidad, alta estabilidad química, no sufre corrosión, resistencia química y microbiana y excelentes propiedades estéticas. Objetivo: El objetivo de este estudio fue evaluar las condiciones superficiales de ZrO2 para su aplicación clínica a los implantes transendodónticos. Materiales y Métodos: se trituraron bloques de ZrO2 en implantes trans-endodónticos y se dividieron en: monoclínico y tetragonal. Luego se evaluaron mediante microscopía electrónica de barrido (SEM), espectroscopia de rayos X de energía dispersiva (EDS) y microscopio de fuerza atómica (AFM) y microdureza vickers. Resultados: La fase monoclínica a través del análisis AFM presenta Ra = 0.320 μm, mientras que en la fase Tetragonal es 0.126 μm, SEM / EDS muestra que las fases no son adecuadamente uniformes y la adición del Ytrio para favorecer la estabilización de la fase tetragonal. El análisis de microdureza mostro un valor de 1500HV. Conclusión: La caracterización de la superficie de los implantes trans-endodónticos de óxido de zirconio, brinda una pauta para conocer las características superficiales del material, ya que al haber una mayor rugosidad en la superficie del implante se verá favorecida la capacidad de oseointegración.

Can the application of multi-mode adhesive be a substitute to silicatized/silanized y-tzp ceramics?

Abstract This study evaluated the effectiveness of a multi-mode adhesive (SBU-Scotch Bond Universal/3M) as a substitute for silica coating and silane application on the bonding of zirconia ceramics to resin cement. One-hundred and twenty sintered zirconia ceramic blocks (5 x 5 x 5 mm) were obtained, finished by grounding with silicon carbide paper (#600, #800, #1000 and #1200) and randomly divided into 12 groups (n=10) in accordance with the factors "surface treatment" (ScSi - silicatization + silanization; ScSBU - silicatization + SBU; SBU - SBU without photoactivation and SBUp - SBU photoactivated) and "ceramic" (Lava / 3M ESPE, Ceramill Zirconia / Amann Girrbach and Zirkonzahn / Zirkonzahn). Dual resin cement cylinders (RelyX Ultimate/3M ESPE) were subsequently produced in the center of each block using a silicon matrix (Ø=2 mm, h=5 mm) and photoactivated for 40 s (1200 mW/cm2). The samples were stored for 30 days in distilled water (37ºC) and submitted to shear bond strength test (1 mm/min, 100 KgF). Data (MPa) were analyzed under ANOVA (2 levels) and Tukey test (5%). Complementary analyzes were also performed. ANOVA revealed that only the factor "surface treatment" was significant (p=0.0001). The ScSi treatment (14.28A) promoted statistically higher bond strength values than the other ScSBU (9.03B), SBU (8.47B) and SBUp (7.82B), which were similar to each other (Tukey). Failure analysis revealed that 100% of the failures were mixed. The silica coating followed by the silanization promoted higher bond strength values of resin cement and ceramic, regardless of the zirconia ceramic or SBU.

Resumo Este estudo avaliou a efetividade de um adesivo "multi-mode" (Single Bond Universal/3M) como um substituto para a silicatização e aplicação do silano na resistência de união das cerâmicas de zircônia e um cimento resinoso. Para isso, 120 blocos cerâmicos sinterizados de zircônia nas dimensões de (5 x 5 x 5 mm) foram obtidos, lixados com lixas de granulação decrescente (#600, #800, #1000 e #1200) e divididos aleatoriamente em 12 grupos (n = 10), de acordo com os fatores "tratamento de superfície" (ScSi - silicatização + silanização; ScSBU - silicatização + Single Bond; SBU - SBU sem fotoativação e SBUp - SBU com fotoativação) e "cerâmica" (Lava/3M ESPE, Ceramill Zircônia/ Amann Girrbach e Zirkonzahn/Zirkonzahn). Posteriormente, cilindros de cimento resinoso dual (RelyX Ultimate/3M ESPE) foram confeccionados no centro de cada bloco com auxílio de uma matriz de silicone (Ø=2 mm; h=5 mm) e fotopolimerizados por 40 s (1200 mW/ cm²). Em seguida, as amostras foram armazenadas durante trinta dias em água destilada (37 °C) e submetidas ao ensaio de resistência de união ao cisalhamento (1 mm/min, 100 kgF). Os dados (MPa) foram analisados sob ANOVA (2 fatores) e teste de Tukey (5%). Análises complementares também foram realizadas. ANOVA revelou que apenas o fator "tratamento de superfície" foi significativo (p=0,0001). O tratamento ScSi (14.28A) promoveu valores de adesão estatisticamente superiores aos demais ScSBU (9.03B), SBU (8.47B) e SBUp (7.82B), os quais foram semelhantes entre si (Tukey). A Análise de falhas revelou que 100% da falhas que ocorreram foram mistas. A silicatização seguida da silanização promoveu a melhor resistência de união entre cimento resinoso e a cerâmica, independentemente do tipo da cerâmica ou do SBU.

In vitro and in vivo biocompatibility of reoss® in powder and putty configurations

Article This study evaluated comparatively two configurations (powder and putty) of a composite biomaterial based on PLGA (Poly(lactide-co-glycolide)/nanoescale hydroxyapatite (ReOss®, Intra-Lock International) through microscopic morphology, in vitro cytotoxicity, biocompatibility and in vivo response as a bone substitute. SEM and EDS characterized the biomaterials before/after grafting. Cytocompatibility was assessed with murine pre-osteoblasts. Osteoconductivity and biocompatibility were evaluated in White New Zealand rabbits. Both configurations were implanted in the calvaria of eighteen animals in non-critical size defects, with blood clot as the control group. After 30, 60 and 90 days, the animals were euthanized and the fragments containing the biomaterials and controls were harvested. Bone blocks were embedded in paraffin (n=15) aiming at histological and histomorphometric analysis, and in resin (n=3) aiming at SEM and EDS. Before implantation, the putty configuration showed both a porous and a fibrous morphological phase. Powder revealed porous particles with variable granulometry. EDS showed calcium, carbon, and oxygen in putty configuration, while powder also showed phosphorus. After implantation EDS revealed calcium, carbon, and oxygen in both configurations. The materials were considered cytotoxic by the XTT test. Histological analysis showed new bone formation and no inflammatory reaction at implant sites. However, the histomorphometric analysis indicated that the amount of newly formed bone was not statistically different between experimental groups. Although both materials presented in vitro cytotoxicity, they were biocompatible and osteoconductive. The configuration of ReOss® affected morphological characteristics and the in vitro cytocompatibility but did not impact on the in vivo biological response, as measured by the present model.

Resumo Este estudo avaliou comparativamente duas configurações (pó e massa) de um biomaterial composto com base de PLGA (Poli(láctico-co-glicólico)/hidroxiapatita em nanoescala (ReOss®, Intra-Lock International) através da morfologia microscópica, citotoxicidade in vitro, biocompatibilidade e resposta in vivo como substituto ósseo. MEV e EDS caracterizaram os biomateriais antes/após o enxerto. A citocompatibilidade foi avaliada em pré-osteoblastos murinos. A osteocondutividade e a biocompatibilidade foram avaliadas em coelhos Branco da Nova Zelândia. Ambas as configurações foram implantadas na calvária de dezoito animais em defeitos não-críticos, com coágulo sanguíneo como grupo controle. Após 30, 60 e 90 dias, os animais foram eutanasiados e os fragmentos contendo os biomateriais e controles coletados. Blocos ósseos foram embebidos em parafina (n=15) destinados às análises histológica e histomorfométrica, e em resina (n=3) destinadas à MEV e EDS. Antes da implantação, a configuração massa mostrou ambas fases morfológicas porosa e fibrosa. O pó revelou partículas porosas com granulometria variável. EDS mostrou cálcio, carbono e oxigênio na configuração massa, enquanto o pó mostrou também fósforo. Após a implantação a EDS revelou cálcio, carbono e oxigênio em ambas configurações. Os materiais foram considerados citotóxicos pelo teste XTT. A análise histológica mostrou nova formação óssea e nenhuma reação inflamatória nos sítios de implante. Entretanto, a análise histomorfométrica indicou que a quantidade de osso neoformado não foi estatisticamente diferente entre os grupos experimentais. Embora ambos os materiais tenham apresentado citotoxicidade in vitro, foram biocompatíveis e osteocondutores. A configuração do ReOss® afetou as características morfológicas e a citocompatibilidade in vitro, porém não impactou a resposta biológica in vivo, como medido pelo presente modelo.

In vitro effects of alcohol-containing mouthwashes on human enamel and restorative materials

Abstract The objective of this study was to evaluate the in vitro effects, including surface morphological characteristics and chemical elemental properties, of different mouthwash formulations on enamel and dental restorative materials, simulating up to 6 months of daily use. Human enamel samples, hydroxyapatite, composite resin, and ceramic surfaces were exposed to 3 different mouthwashes according to label directions — Listerine® Cool Mint®, Listerine® Total Care, and Listerine® Whitening — versus control (hydroalcohol solution) to simulate daily use for up to 6 months. The samples were analyzed using scanning electron microscopy (SEM), infrared spectrophotometry (µ-Fourier transform infrared microscopy), energy-dispersive X-ray (EDX) spectroscopy, and color analysis before and after exposure. No relevant changes were observed in the morphological characteristics of the surfaces using SEM techniques. The physical and chemical aspects of the enamel surfaces were evaluated using mid-infrared spectroscopy, and EDX fluorescence was used to evaluate the elemental aspects of each surface. There was no variation in the relative concentrations of calcium and phosphorus in enamel, silicon and barium in composite resin, and silicon and aluminum in the ceramic material before and after treatment. No relevant changes were detected in the biochemical and color properties of any specimen, except with Listerine® Whitening mouthwash, which demonstrated a whitening effect on enamel surfaces. Long-term exposure to low pH, alcohol-containing, and peroxide-containing mouthwash formulations caused no ultra-structural or chemical elemental changes in human enamel or dental restorative materials in vitro.

Simplified micrometric surface characterization of different implant surfaces available on the Brazilian market

Aim: This study characterized the implant surfaces available on the Brazilian market in terms of topography, chemical composition, and roughness. Methods: The following brands were selected according to their surfaces: Kopp (Ko), Signo Vinces (Sv), Neodent (Ne), Osseotite (Os) NanoTite (Nt), SIN (Si), Titanium Fix (Tf), conventional Straumann (Str), Active SLA (SLA). The morphological analysis and the alloy impurities and implant surface contaminants were analyzed by SEM-EDS. Surface roughness parameters and 3-D reconstructions were obtained by laser microscopy (20x). Two distinct areas were evaluated: i) the cervical portion (no surface treatment), and ii) the middle third (treated surface). Results: The characterization of the implant surfaces by SEM showed morphological differences between the thread geometries and surface morphology at 800x and 2000x magnification. The EDS elemental analysis showed a predominance of titanium (Ti) for all implants. The SLA surface showed only peaks of Ti while other implants brands showed traces of impurities and contaminants including Al, C, PR, F, Mg, Na, Ni, O, P, and SR. The implant surface roughness in the cervical portion did not exceed Ra 0.5­1.0 µm, constituting a minimally rough surface and obtaining acceptable standards for this region. Only Nt, Str, and SLA presented Ra above 2 µm in the middle third area showing a rough surface favorable for osseointegration. Conclusion: This study concluded that there is no established standard for morphology, chemical composition and implant surface roughness that allows a safe comparison between the available dental implant surfaces. National implant brands generally contain more impurities and surface contaminants than their international counterparts and were consequently more sensitive to the surface treatment techniques