Radiopacity and physical properties evaluation of infiltrants with Barium and Ytterbium addition

Abstract Radiopaque properties in the infiltrant should be interesting for clinicians to feel more confident to indicate this treatment. Thus, the aim of this study was to evaluate the effect of the incorporation of barium and ytterbium particles on the physical properties of resin infiltrants. Groups were divided according to the addition of ytterbium oxide (Y) alone (30 or 40%) or Y with barium (YB) (15/15% or 20/20% respectively) in the Icon commercial infiltrant and in the experimental infiltrant base. Digital radiography (n=5), Microradiography (n=5), Microtomography (n=3), degree of conversion (n=5), water sorption (n=16), solubility (n=16), contact angle (n=16), flexural strength (n=16), elastic modulus (n=16) and Energy dispersive X-ray Spectroscopy (n=10) were performed. Analyses were performed using the R program, with a significance level of 5%, and microradiography and Microtomography analyses were evaluated qualitatively. In groups with 30 or 40% of ytterbium, radiopacity was higher or equal to enamel. Microradiography and Microtomography appear to have more radiopacity in groups with 40% (Y). Among the groups with no particle addition, those of the experimental infiltrant presented a higher degree of conversion than those of Icon®. In most groups, there was solubility below the ISO-recommended levels. The addition of particles resulted in higher viscosity. Groups with Icon had higher flexural strength and elastic modulus than groups with experimental infiltrant. The addition of 40% (Y) improved polymerization, had low solubility, and had greater radiopacity than enamel, however negatively affected the viscosity increasing then. Experimental groups with the base showed a higher water sorption than Icon groups.

Resumo O objetivo desse estudo foi avaliar o efeito da incorporação de partículas de Bário e Itérbio nas propriedades físicas de infiltrantes resinosos. Os grupos foram divididos de acordo com a adição de Itérbio puro (30 ou 40%) ou Itérbio com Bário (15/15% ou 20/20% respectivamente) no infiltrante comercial Icon e no Infiltrante experimental base. Foram realizados os testes de: radiografia digital (n=5), microradiografia Transversa (n=5), microtomografia (n=3), grau de conversão (n=5), sorção (n=16), solubilidade (n=16), ângulo de contato (n=16), resistência flexural (n=16), modulo de elasticidade (n=16) e Espectroscopia por energia dispersiva (n=10). As análises foram realizadas utilizando o programa R, com nível de significância de 5%, e os testes de microradiografia e microtomografia foram analisados qualitativamente. Nos grupos com 30 ou 40% de Itérbio, a radiopacidade foi maior ou igual ao esmalte dentário. Na microradiografia e microtomografia parece ter maior radiopacidade nos grupos com 40% de itérbio. Dentre os grupos sem adição de partículas, os do infiltrante experimental apresentaram maior grau de conversão do que os do Icon e o grupo controle experimental e com 40% de itérbio apresentaram os melhores resultados. Na maioria dos grupos, a solubilidade foi abaixo dos níveis recomendados pela ISO. A adição de particulas resultou em maior viscosidade. Os grupos com Icon apresentaram maior resistência flexural e modulo de elasticidade do que os grupos com infiltrante experimental e a quantidade de partícula aumentou a resistência e o módulo de elasticidade. A adição de 40% de itérbio melhorou a polimerização, apresentou baixa solubilidade e maior radiopacidade do que o esmalte, porém afetou negativamente a viscosidade, aumentando-a.

The effect of adding ytterbium trifluoride on the radiopacity, compressive strength, setting time and bioactivity of biodentine: an in vitro study / Efeito da adição de trifluoreto de itérbio na radiopacidade, resistência à compressão, tempo de presa e bioatividade da biodentina: estudo in vitro

Objective: This study aimed to evaluate the radiopacity, compressive strength, setting time and bioactivity of Biodentine after modification with Ytterbium Tri-Fluoride (YbF3) in three different concentrations. Material and Methods: Radiopacity was determined using the equivalence in millimeters of aluminum (mm Al) from digital radiographs. Compressive strength was evaluated using a universal testing machine. The initial and final setting times were evaluated using Gillmore needle. The bioactive potential was evaluated using the environmental scanning electron microscope (ESEM) connected with Energy Dispersive X-ray analysis (EDX) and X-ray Diffractometer (XRD) at three different time intervals. pH was measured using a pH-meter. Data were analyzed using one-way ANOVA followed by Tukey's post hoc tests (P≤ 0.05). Results: Radiopacity of Biodentine with 2.5%, 5% and 7.5% YbF3 was significantly higher than unmodified Biodentine (P ≤ 0.05). Unmodified Biodentine showed the highest mean compressive strength values compared to all other groups (p≤ 0.05). The addition of YbF3 to Biodentine has extended the final setting time except for the 2.5% YbF3 group that showed no significant difference compared to the control. All groups showed an alkaline pH at 28 days, ESEM coupled with EDX analysis showed evidence of dense globules of calcium phosphate on the surface indicating enhancement of bioactivity. Conclusion: 2.5% YbF3 can be a promising radiopacifying agent to Biodentine with improvement in radiopacity, bioactive potential and maintaining the setting time and compressive strength at acceptable level as indicated by the ISO standards (AU)

Objetivo: O estudo buscou avaliar a radiopacidade, resistência à compressão, tempo de presa e bioatividade da Biodentina modificada por Trifluoreto de itérbio (YbF3). Materiais e Métodos: YbF3 foi incorporado ao pó de Biodentina e dividido em 4 grupos (X0, X1, X2 e X3) de acordo com a concentração de YbF3; 0%, 2.5%, 5% e 7.5% do peso, respectivamente. Os espécimes foram preparados para cada experimento com um total de 40 espécimes para cada teste (n=10 por grupo). A radiopacidade foi determinada através do uso equivalente em milímetros de alumínio. A resistência a compressão foi avaliada através do uso de uma máquina de teste universal. O tempo inicial e final foi avaliado através de uma agulha de Gillmore. O potencial bioativo foi avaliado através do Microscópio Eletrônico de Varredura (ESEM), conectado com a análise de espectroscopia de raios X por energia dispersiva (EDX) e difração de raio X (DRX). O pH foi mensurado através do uso de um pHmetro. Os dados foram analisados pelo ANOVA seguido do Test Tukey. Resultados: A radiopacidade nos grupos X1, X2 e X3 foi significantemente maior do que no grupo X0. O grupo X0 mostrou a maior resistência à compressão comparado com os outros grupos. A adição de YbF3 a Biodentina excedeu o tempo final exceto pelo grupo X1, que não apresentou diferença estatística significante quando comparado com o grupo X0. Todos os grupos apresentaram um pH alcalino com 28 dias. ESEM com análise EDX mostrou evidência de densos glóbulos de fosfato de cálcio na superfície, indicando uma melhora na bioatividade. Conclusão: 2.5% YbF3 é um promissor radiopacificador para Biodentina, que aumentou a radiopacidade e potencial bioativo enquanto manteve o tempo definido e a resistência à compressão em níveis aceitáveis como indica a norma ISO.(AU)

Estudo comparativo da osseointegração de implantes manufaturados em Ti-cp ou Ti6Al4V com ou sem superfície modificada por ablação a laser: caracterização topográfica, análises biomecânica, histólogica e imunoistoquímica / Comparative study of osseointegration of implants manufactured in cp-Ti or Ti6Al4V with or without modified surface by laser beam: topographic characterization, biomechanical, histological and immunohistochemical analyzes

A proposição do trabalho foi avaliar o comportamento biológico e mecânico ao tecido ósseo periimplantar em implantes manufaturados em Ti-cp com superfícies usinada (CPMS) e modificada por LASER (CPLS) e implantes manufaturados em Ti6Al4V com superfícies usinada (ALLOYMS) e modificada por LASER (ALLOYLS). As superfícies foram analisadas por meio da microscopia eletrônica de varredura acoplado a espectroscopia por energia dispersiva de raios X (MEV-EDX) previamente a cirurgia experimental. Noventa e seis (2x4mm) implantes foram instalados em leitos cirúrgicos fresados nas tíbias direita e esquerda de 48 ratos Wistar machos, sendo um implante de cada material (metal) ou superfície instalado em cada tíbia. Análise biomecânica foi realizada por meio do torque de remoção dos implantes em todos os grupos nos períodos de 14, 21 e 42 dias pós-operatório e as tíbias foram seccionadas e processadas para análise histológica e imunoistoquímica. Posteriormente, foi realizada MEV-EDX dos implantes removidos por torque reverso em todos os períodos de análises. Os dados obtidos na análise biomecânica foram submetidos à análise estatística (p< 0,05). MEV-EDX antes da instalação dos implantes apresentou diferença entre as superfícies usinadas e modificadas por LASER, independente do metal do implante. O torque de remoção de ALLOYLS foi estatisticamente superior a CPLS, CPMS e ALLOYMS em 14 e 21 dias (p < 0,05), bem como CPLS foi estatisticamente superior a CPMS e ALLOYMS. Aos 42 dias CPLS e ALLOYLS apresentaram diferenças estatística quando comparados com CPMS e ALLOYMS (p< 0,05), porém não foi observada diferença entre CPLS e ALLOYLS (p = 0,07). O MEV-EDX dos implantes removidos por contra-torque evidenciou o recobrimento ósseo total das superfícies de CPLS e ALLOYLS, independe do período analisado e um aumento gradual de recobrimento ósseo nas superfícies de CPMS e ALLOYMS nos períodos de 14, 21 e 42 dias respectivamente, sendo que o CPLS aos 42 dias apresentou característica de tecido ósseo mais maturo. Na análise histológica qualitativa observa-se um tecido ósseo mais maturo, sugerindo aceleração do processo de reparo ósseo nos grupos CPLS e ALLOYLS. Para análise imunoistoquímica observou-se uma maior expressão de OPN (osteopontina) para os grupos ALLOYLS 14 e 21 dias pós-operatório, surgindo de maior ativação celular. Os implantes com modificação de superfície por ablação a LASER, independente do material manufaturado, proporcionaram importantes modificações físico-químicas na superfície, permitindo melhor embricamento mecânico com o tecido ósseo e aceleração do processo de osseointegração quando comparados com implantes com superfície usinada(AU)

This study aimed to evaluate the biological and mechanical behavior of peri-implant bone tissue in implants manufactured in cp-Ti with machined surfaces (CPMS) and modified by LASER (CPLS) and implants manufactured in Ti6Al4V with machined surfaces (ALLOYMS) and modified by LASER (ALLOYLS). The surfaces were analyzed using scanning electron microscopy coupled with X-ray dispersive energy spectroscopy (SEM-EDX) prior to experimental surgery. Ninety-six (2x4mm) implants were installed in surgical beds milled in the right and left tibias of 48 male Wistar rats, one implant of each material (metal) or surface installed in each tibia. Biomechanical analysis was performed using the implant removal torque in all groups in the periods of 14, 21 and 42 days postoperatively and the tibias were sectioned and processed for histological and immunohistochemical analysis. The data obtained in the biomechanical analysis were submitted to statistical analysis (p < 0.05). The SEM-EDX before the installation of the implants showed a difference between the surfaces machined and modified by LASER, regardless of the metal of the implant. The removal torque of ALLOYLS was statistically higher than CPLS, CPMS and ALLOYMS in 14 and 21 days (p < 0.05), as well as CPLS was statistically higher than CPMS and ALLOYMS. In 42 days CPLS and ALLOYLS showed statistical differences when compared to CPMS and ALLOYMS (p < 0.05), however no difference was observed between CPLS and ALLOYLS (p = 0.07). The SEM-EDX of the implants removed by removal torque showed the total bone coverage of the surfaces of CPLS and ALLOYLS, regardless of the analyzed period and a gradual increase in bone coverage on the surfaces of CPMS and ALLOYMS in the periods of 14, 21 and 42 days respectively, CPLS in 42 days showed a mature bone tissue. In the qualitative histological analysis, a mature bone can be observed, suggesting an acceleration of the repair process in the CPLS and ALLOYLS groups. For immunohistochemical analysis, a higher expression of OPN (osteopontin) was observed for the ALLOYLS groups in 14 and 21 days, arising from higher cellular activation. The implants with surface modification by LASER beam, regardless of the material manufactured, provided important physical-chemical modifications on the surface, allowing better mechanical resistance with bone tissue and acceleration of the osseointegration process when compared to implants with machined surfasse(AU)

Ytterbium oxide as radiopacifier of calcium silicate-based cements. physicochemical and biological properties

Abstract This study evaluated physicochemical properties, cytotoxicity and bioactivity of MTA Angelus (MTA), calcium silicate-based cement (CSC) and CSC with 30% Ytterbium oxide (CSC/Yb2O3). Setting time was evaluated using Gilmore needles. Compressive strength was evaluated in a mechanical machine. Radiopacity was evaluated using radiographs of materials and an aluminum scale. Solubility was evaluated after immersion in water. Cell viability was evaluated by means of MTT assay and neutral red staining, and the mineralization activity by using alkaline phosphatase activity and Alizarin Red staining. The data were submitted to ANOVA, Tukey and Bonferroni tests (5% significance). The bioactive potential was evaluated by scanning electron microscopy. The materials presented similar setting time. MTA showed the lowest compressive strength. MTA and CSC/Yb2O3 presented similar radiopacity. CSC/Yb2O3 showed low solubility. Saos-2 cell viability tests showed no cytotoxic effect, except to 1:1 dilution in NR assay which had lower cell viability when compared to the control. ALP at 1 and 7 days was similar to the control. MTA and CSC had greater ALP activity at 3 days when compared to control. All the materials present higher mineralized nodules when compared with the control. SEM analysis showed structures suggesting the presence of calcium phosphate on the surface of materials demonstrating bioactivity. Ytterbium oxide proved to be a properly radiopacifying agent for calcium silicate-based cement since it did not affected the physicochemical and biological properties besides preserving the bioactive potential of this material.

Resumo Este estudo avaliou as propriedades físico-químicas, citotoxicidade e bioatividade do MTA Angelus (MTA), cimento à base de silicato de cálcio (CSC) e CSC com 30% de óxido de itérbio (CSC/Yb2O3). O tempo de presa foi avaliado usando agulhas Gilmore. A resistência à compressão foi avaliada em uma máquina mecânica. A radiopacidade foi avaliada utilizando radiografias dos materiais e uma escala de alumínio. A solubilidade foi avaliada após imersão em água. A viabilidade celular foi avaliada por meio do ensaio MTT e coloração de vermelho neutro (NR), e a atividade de mineralização por meio da atividade da fosfatase alcalina e a coloração com Vermelho de Alizarina. Os dados foram submetidos aos testes ANOVA, Tukey e Bonferroni (5% de significância). O potencial bioativo foi avaliado por microscopia eletrônica de varredura. Os materiais apresentaram tempo de presa semelhante. O MTA mostrou menor resistência à compressão. MTA e CSC/Yb2O3 apresentaram radiopacidade semelhante. CSC/Yb2O3 apresentou menores valores de solubilidade. A viabilidade celular realizada pelos ensaios de MTT e NR não revelaram efeitos ctotóxicos em todas as diluições, exceto na diluição 1:1 no NR, o qual mostrou baixa viabilidade celular (p<0.05) em todos materiais testados quando comparado ao controle. A atividade de ALP em 1 e 7 dias foi similar ao controle (p>0.05). MTA e CSC tiveram significante aumento na atividade de ALP aos 3 dias quando comarados ao controle (p>0.05). Todos os materiais apresentaram grande produção de nódulos mineralizados quando comparados ao controle (P<0.05). A análise da SEM mostrou estruturas que sugerem a presença de depósitos de fosfato de cálcio na superfície dos materiais demonstrando bioatividade. O Yb2O3 mostrou ser um agente radiopacificador adequado em cimentos à base de silicato de cálcio uma vez que não afetou as propriedades físico-químicas e biológicas e ainda preservou o potencial bioativo desse material.

Microscopic description of low-lying properties in 168≤A≤170 Yb nuclei by the pseudo-SU(3) shell model / Descripción microscópica de las propiedades de baja energía de los núcleos 168≤A≤170 Yb usando el modelo pseudo-SU(3)

Abstract The rare-earth nuclei have well-known collective properties. The theoretical description of these nuclei represents a challenge to nuclear models, due to the enormous dimensions of the valence space, making the problem unmanageable. This leads us to use symmetry-based models, where it is possible to calculate in a free-truncation environment. In this work we present results for the energy spectrum and the electromagnetic properties in even-even Yb isotopes using the pseudo-SU(3) shell model. The model considers a Nilsson Hamiltonian that additionally includes the quadrupole-quadrupole and pairing interactions, systematically parameterized. The results show that the model considered is a powerful theoretical tool, allowing us to describe the normal parity sector of deformed rare earth nuclei.

Resumen Las propiedades colectivas de los núcleos de las tierras raras están muy bien determinadas. La descripción teórica de estos núcleos representa un desafío para cualquier modelo nuclear debido a las dimensiones excesivas del espacio de valencia, lo que vuelve el problema inmanejable. Esto nos lleva a emplear modelos basados en simetrías, donde es posible realizar cálculos sin truncamiento del espacio. En este trabajo se presentan resultados para el espectro energético y las propiedades electromagnéticas en isótopos para-par de iterbio, utilizando el modelo de capas pseudo-SU(3). El modelo considera el hamiltoniano de Nilsson, al que adicionalmente se le han incluido las interacciones cuadrupolo-cuadrupolo y de apareamiento, parametrizadas de forma sistemática. El resultado muestra que el modelo utilizado es una herramienta poderosa que permite describir el sector de paridad normal del espectro de núcleos deformados de las tierras raras.

Effects of surgery combined with isotope 90 Sr-90Y ortriamcinolone acetonide on hypertrphic scar in rabbit ears / 中华医学美学美容杂志

Objective To explore the best way and the security of hypertrophic scar treatment by surgery combined with isotopic 90 Sr-90 Y or triamcinolone acetonide.Methods Hypertrophic scar of rabbit ears were divided into direct treatment group (Group A received 90 Sr-90Y irradiation,Group D received triamcinolone acetonide),two days 90 Sr-90 Y irradiation after surgery repair group (Group B),one week treatment after surgery repair group (Group C received 90Sr-90 Y irradiation,Group E received triamcinolone acetonide),saline injection group (Group F received saline directly,Group G received saline injection after surgical repair one week later),Group H received nothing,and then the histological changes were compared in each group.Results The 90Sr-90 Y exposure groups (Groups A,B,C) and triamcinolone acetonide injection groups (Groups D and E),the number of fibroblasts,collagen fiber surface density,microvessel counts and α-SMA-positive particle optical density values were significantly lower than the saline groups (Groups F,G) and blank control group.The most obvious group was Group B; Groups A,C,D,and E were not statistically significant.The number of melanoma cells of 90Sr-90Y exposure group (Groups A,B,and C) was significantly lower than other groups,with statistically significant difference.Atypical cells were not found in 90Sr-90 Y applicator exposure group.Conclusions Isotope 90 Sr-90 Y and triamcinolone acetonide inhibits the proliferation of the rabbit ear hypertrophic scar,the scar tissue fibrosis is reduced significantly,but there is no significant difference between the two effects.Early isotope 90 Sr-90 Y intervention on hypertrophic scar can achieve better results.Hypertrophic scar by isotope 90 Sr-90 Y radiation is easy to cause depigmentation,but generally does not cause cancer.

Influence of radiopaque fillers on physicochemical properties of a model epoxy resin-based root canal sealer

Objective: To verify the influence of radiopaque fillers on an epoxy resin-based sealer. Material and Methods: Experimental sealers were formulated by adding 20%, 40%, 60%, 80%, 100% and 120% of calcium tungstate, ytterbium trifluoride or barium sulphate by weight to an epoxy-resin-base. Setting time, flow, film thickness, radiopacity, sorption, solubility, pH and push-out bond strength were evaluated. Results: The setting time ranged from 373 to 612.66 min, the flow varied from 13.81±0.49 to 22.49±0.37 mm, and the film thickness ranged from 16.67±5.77 to 33.33±11.54 µm. The lowest pH was 5.47±0.53, and the highest was 6.99±0.03. Radiopacity varied from 0.38±0.04 to 2.57±0.21 mmAl and increased with the amount of filler. Calcium tungstate sealers had a higher sorption and solubility than other sealers. There was no significant difference in the push-out bond strength among the fillers at the 120% concentration. CONCLUSION: The inorganic fillers evaluated and their concentrations affect the physicochemical properties of an epoxy resin-based root canal sealer. .

COMPARISON OF METABOLIC BALANCE AND FECAL MORNITORING METHODS FOR ESTIMATING THE DIETARY ZINC ABSORPTION IN TIBETAN MEN / 营养学报

Objective: To compare the methods of metabolic balance (MB) and fecal monitoring (FM) for evaluating the dietary zinc (Zn) absorption in Tibetan men. Methods: In 14 d field trial on 16 adult Tibetan men, capsules of carmine were given to mark the feces from D4 to D12, and samples of diet, water, feces and urine were collected during the period. In addition, 4.0 mg zinc tracer (enriched with 67Zn) and 1.0 mg recovery indicator ytterbium (Yb) were orally administrated to the subjects in the evening meal of the D5. The ratio of 67Zn/68Zn in fecal samples was determined by inductively coupled plasma mass spectrometry, and then the zinc absorption was calculated based on the principle of isotope dilution. Results: The dietary zinc absorption in Tibetan men was (23.8?3.9) % evaluated by MB and (21.4?4.3) % by FM with significant difference (by paired-samples t test) and linear correlation (Pearson). The unabsorbed zinc tracer and Yb had the similar behavior through the digestive tract, mostly excreted within5 d following the intake. Conclusion: In the 14d metabolic period, the dietary zinc absorption from MB was a little higher than that from FM. Using FM, the metabolic period can be shortened to 4-5 days according to excretion of Yb. Both methods suggested that the dietary zinc absorption in the adult Tibetan men was good.