Influência de diferentes tipos e concentrações de catalisadores químicos na eficiência do clareamento dental

O objetivo deste estudo foi avaliar a eficiência de diferentes tipos e concentrações de catalisadores químicos sobre a efetividade de um gel a base de peróxido de hidrogênio a 35% no clareamento dental. Foram utilizados 170 dentes incisivos bovinos dos quais foram obtidos 510 discos de esmalte-dentina, com 3mm de diâmetro, utilizando-se broca tipo trefina. A leitura da cor dos espécimes foi realizada com um espectrofotômetro de refletância. Foi utilizado para todos os grupos um gel experimental a base de peróxido de hidrogênio a 35%. Para avaliação dos catalisadores químicos, os espécimes foram divididos em grupos de acordo com o tipo e a concentração da substância adicionada: SF - Sulfato Ferroso (0,001%, 0,002% e 0,003%), GF - Gluconato Ferroso (0,01%, 0,02% e 0,03%), CF - Cloreto Férrico (0,01%, 0,02% e 0,03%), GM - Gluconato de Manganês (0,01%, 0,02% e 0,03%) e CM - Cloreto de Manganês (0,01%, 0,02% e 0,03%). Dois grupos controle foram preparados, sendo eles um grupo controle positivo (CP), na qual não foi adicionado nenhum catalisador químico ao gel clareador, e um grupo controle negativo (CN), onde os espécimes não foram clareados e foram apenas submersos em saliva artificial. Sobre a superfície de esmalte foram realizadas 3 aplicações dos respectivos géis clareadores por 10 min cada, as quais foram repetidas após 7 dias, totalizando 2 sessões de 30 minutos. Foram feitas avaliações de cor antes do clareamento, 7 dias após da primeira sessão e 7 dias após a segunda. Os espécimes foram armazenados em saliva artificial e novamente avaliados após 1 ano. Os dados foram analisados pelos testes de análise da variância paramétrica (ANOVA) e teste de Tukey. Os resultados mostraram que o uso de alguns dos ativadores químicos testados foram efetivos em reduzir o amarelamento das amostras...

Adjuvantes na deriva de 2,4-D + glyphosate em condições de campo

The aim of the research was to evaluate the effect of adjuvants on the spray drift applications from mixture of 2,4-D + glyphosate. The trial was carried out in field conditions in a completely randomized design. The treatments corresponded to solutions containing mixture of the herbicides 2,4-D + glyphosate (670 and 1068g ha-1, respectively) adding the adjuvants (v v-1): mineral oil (0.5%); anti-drift agent (0.09%); spreader-sticker A (0.1%); liquid fertilizer (0.05%); spreader-sticker B (0.25%); and only herbicides without adjuvantes (control). Nylon strings were used to drift determination outside the application area (1, 5, 10, 20, 50, 100 and 200 m away) with 4 replications and six foam cylinders placed on the boom of the sprayer were used to collect the droplets subject to drift. The applications were performed simultaneously, using a specific salt tracer for each spray solution to quantify the deposits by spectrophotometer. It was not possible to verify effect of the adjuvants on drift at different distances of the application area. Based on droplets collected above the boom spray, it was found that susceptibility to drift was lower with the mineral oil and the anti-drift agent. The drift risk was higher with the liquid fertilizer and the spreader-sticker B.

Efeito da amoxicilina e do fluoreto no desenvolvimento do esmalte dentário de ratos

Pós-graduação em Ciências Odontológicas - FOAR

Avaliação de propriedades físico-químicas, mecânicas e antimicrobianos do MTA e cimento Portland associado a solução de nanopartículas de prata

Pós-graduação em Odontologia - FOAR

Prostatic acid phosphatase in serum and semen of dogs

The incidence of prostatic malignancy has increased the use of tissue markers to detect cancer. Tissue specific antigens or differentiation antigens are found on the surface of normal cells. Clinically, these antigens are important to diagnose alterations in the tissues and for immunotherapy. The objective of the present study was to evaluate the prostatic acid phosphatase concentration in blood and seminal plasma of intact and healthy dogs at different ages. The evaluation was carried out by spectrophotometer, using a commercial kit. The prostatic acid phosphatase (PAP) levels did not differ according to the age and did not correlate with age or prostatic dimensions verified by ultrasonography. The PAP concentration values varied greatly within each group. However, more studies are necessary to evaluate the role of prostatic acid phosphatase in the canine prostate and its importance as a diagnostic test for prostate disorders.

Transenamel and Transdentinal Penetration of Hydrogen Peroxide Applied to Cracked or Microabrasioned Enamel

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Chromatic changes to artificial irises produced using different techniques

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Effect of intrinsic nanoparticle pigmentation on the color stability of denture base acrylic resins

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

The impact of the addition of iodoform on the physicochemical properties of an epoxy-based endodontic sealer

Due to the low radiopacity of Sealer 26, iodoform is frequently empirically added to this sealer. Thus, the interference of this procedure with the physicochemical properties of Sealer 26 must be evaluated. Objective: This study evaluated the influence of the addition of iodoform on setting time, flow, solubility, pH, and calcium release of an epoxy-based sealer. Material and Methods: The control group was pure Sealer 26, and the experimental groups were Sealer 26 added with 1.1 g, 0.55 g or 0.275 g of iodoform. Setting time evaluation was performed in accordance with the ASTM C266-03 speciflcation. The analysis of flow and solubility was in accordance with the ISO 6876-2001 speciflcation. For the evaluation of pH and calcium ion release, polyethylene tubes were filled with the materials and immersed in flasks with 10 ml of deionized water. After 24 h, 7, 14, 21, 28, and 45 days pH was measured. In 45 days, the calcium released was evaluated with an atomic absorption spectrophotometer. Results: The addition of iodoform increased setting time in comparison with pure sealer (P < 0.05). As for flow, solubility, and calcium release, the mixtures presented results similar to pure sealer (p > 0.05). In the 24 h period, the mixture with 1.1 g and 0.55 g of iodoform showed lower pH than pure sealer and than sealer added with 0.275 g of iodoform (P < 0.05). Conclusions: The iodoform added to Sealer 26 interferes with its setting time and solubility properties. Further studies are needed to address the clinical signiflcance of this interference.

Bond Strength of Different Resin Cement and Ceramic Shades Bonded to Dentin

Purpose: To evaluate the microtensile bond strength (MTBS) of ceramic cemented to dentin varying the resin cement and ceramic shades.Materials and Methods: Two VITA VM7 ceramic shades (Base Dentine 0M1 and Base Dentine 5M3) were used. A spectrophotometer was used to determine the percentage translucency of ceramic (thickness: 2.5 mm). For the MTBS test, 80 molar dentin surfaces were etched and an adhesive was applied. Forty blocks (7.2 x 7.2 x 2.5 mm) of each ceramic shade were produced and the ceramic surface was etched (10% hydrofluoric acid) for 60 s, followed by the application of silane and resin cement (A3 yellow and transparent). The blocks were cemented to dentin using either A3 or transparent cement. Specimens were photoactivated for 20 s or 40 s, stored in distilled water (37 degrees C/24 h), and sectioned. Eight experimental groups were obtained (n = 10). Specimens were tested for MTSB using a universal testing machine. Data were statistically analyzed using ANOVA and Tukey's post-hoc tests (alpha <= 0.05).Results: The percentage translucency of 0M1 and 5M3 ceramics were 10.06 (+/- 0.25)% and 1.34 (+/- 0.02)%, respectively. The lowest MTBS was observed for the ceramic shade 5M3. For the 0M1 ceramic, the A3 yellow cement that was photocured for 20 s exhibited the lowest MTBS, while the transparent cement that was photocured for 40 s presented the highest MTBS.Conclusions: For the 2.5-mm-thick 5M3 ceramic restorations, the MTBS of ceramic cemented to dentin significantly increased. The dual-curing cement Variolink II photocured for 40 s is not recommended for cementing the Base Dentine 5M3 feldspathic ceramic to dentin.

Efeito de diferentes fontes luminosas e pré-condicionamento do esmalte na alteração de cor, penetração de H2O2 e citotoxicidade em dentes clareados

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Hiperacumulação de cádmio em plântulas de Cajanus cajan inoculadas com Pseudomonas

Pós-graduação em Agronomia (Genética e Melhoramento de Plantas) - FCAV

Avaliação do PH e da densidade óptica do corante azul de metileno tamponado e não tamponado após o contato com diferentes cimentos endodônticos

O objetivo deste trabalho foi avaliar o pH e a densidade óptica das soluções de azul de metileno a 1% e 2% (tamponadas e não tamponadas) após a imersão de três cimentos endodônticos. Foram preparados oitenta espécimes de cada cimento endodôntico (Endofill, AH Plus e Sealapex), os quais foram imersos nas soluções corantes. As soluções foram analisadas antes e após a imersão dos materiais nos períodos de tempo de 0, 24, 48 e 72h. Foram realizadas avaliações do pH utilizando um pHmetro e da densidade óptica utilizando um espectofotômetro ajustado em 596nm. Os dados de pH foram analisados através de estatística descritiva e os dados da densidade óptica foram analisados pela ANOVA e teste de Tukey 5%. Pôde-se verificar que as soluções corantes de azul de metileno tamponadas e não tamponadas apresentaram pequena variação nos valores de pH e densidade óptica antes do contato com os cimentos endodônticos. As soluções corantes não tamponadas apresentaram valores de pH menores que as tamponadas, independentemente do contato com qualquer cimento endodôntico. Os cimentos endodônticos promoveram alterações nos valores de pH das soluções corantes, sendo que as maiores alterações ocorreram nas soluções não tamponadas. Ocorreram alterações nos valores da densidade óptica das soluções corantes tamponadas e não tamponadas nos diferentes períodos de tempo de análise, sendo diferentes para cada cimento endodôntico utilizado

Determination of tetramethylthiuram disulfide (thiram) for residual analysis in food using spectrophotometry coupled with a solid-phase reactor (SPR) in a flow system

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Tooth Discoloration Induced by Endodontic Phenothiazine Dyes in Photodynamic Therapy

Objective: This study sought to assess if discoloration of tooth structures occurs after photodynamic therapy (PDT) and to determine the efficacy of a protocol to remove the photosensitizers. Background data: PDT has been used in root canal treatment to enhance cleaning and disinfection of the root canal system. PDT uses a low power laser in association with a dye as a photosensitizer. Photosensitizers can induce staining of the dental structures, resulting in an unaesthetic appearance. Methods: Forty teeth were randomly divided into four groups according to the photosensitizer used and pre-irradiation time: 0.01% methylene blue for 5 min (MB5); 0.01% methylene blue for 10 min (MB 10); 0.01% toluidine blue for 5 min (TB5); and 0.01% toluidine blue for 10 min (TB 10). Specimens were irradiated with a 660 nm diode laser with a 300 mu m diameter optical fiber, at 40 mW power setting for 3 min. Immediately after, the photosensitizers were removed with Endo-PTC cream +2.5% sodium hypochlorite (NaOCl). The shade was measured by a Vita Easyshade spectrophotometer based on the CIELAB color system (L*a*b* values) at three different experimental times: before PDT (T0), immediately after PDT (T1), and after removal of the photosensitizer (T2). Results: The results showed a decrease in the averages of the L*a*b* coordinate values after PDT (T1) in all the groups, when compared with the number at T0, with a significant statistical difference in group MB10. After photosensitizer removal (T2), all the values of the coordinates increased with significant statistical differences (p < 0.05) between T1 and T2 in L* and a*. Conclusions: It can be concluded that both methylene blue and toluidine blue dyes cause tooth discoloration, and that Endo-PTC cream associated with 2.5% NaOCl effectively remove these dyes, regardless of the pre-irradiation time used for PDT.