Uso do etodolaco preemptivo na redução de sensibilidade relacionada ao clareamento dental : estudo clínico randomizado controlado triplo cego

This study evaluated the previous use of Etodolac 400 mg at the tooth sensitivity caused by bleaching procedure. This clinical randomized controlled triple blinded study was done in fifty patients, divided into two groups: Etodolac (intervention) and Placebo (control). One hour before each session, the patients received one different treatment of the first one (crossover). The treatment sequence was randomized previously of the research beginning. A anxiety questionary was applied (Corah scale), and the initial sensitivity evaluation was made by using visual and verbal scales. The bleaching procedure used 35% hydrogen peroxide (Whiteness HP Blue, FGM, Joinvile, SC, Brasil) for 40 minutes in two sessions, with 7 days interval. The sensitivity was measured before, during (20’ and 40’) and 24 hours after the dental bleaching. Color alteration was measured with CieLab system (Easy Shade Spectrophotometer) and Vita Bleach Guide scale in different periods: initial and 7 days after each dental bleaching session. Data for whitening scale were analyzed considering the scoring averages observed at baseline and after each session; and the differences (delta) between two consecutive measurements. The effect of bleaching (delta) obtained between the treatment sequences were compared using the Mann-Whitney test. Differences on presence/ absence of sensitivity were analyzed by Fisher's exact test, and the scales of assessment of tooth sensitivity, the Mann-Whitney test. For both scales of assessment of tooth sensitivity, data from scores in each moment of evaluation / whitening session, were submitted to Mann-Whitney test. The mean scores for each treatment were compared using the Wilcoxon test. The results showed that only using EVA at the second session there was some statistically significant difference, however, it was not possible to eliminate or decrease the sensitivity between treatments in the evaluated times. There was an effective bleaching for both groups, with a variation from 8.4 to 3.7 when using Bleach Guide, and 9.5 to 10.1 for the Easy Shade. The Risk and sensitivity level during and post office bleaching, in general, have not been eliminated with the preemptive use of Etodolac the bleaching procedure.O presente estudo avaliou a eficácia do uso do Etodolaco preemptivo na sensibilidade dental causada pelo clareamento dental. Este ensaio clínico randomizado, controlado triplo cego foi realizado em cinquenta pacientes, usando o Etodolaco 400 mg para o grupo experimental e placebo para o grupo controle. Uma hora antes de cada sessão, cada paciente recebiam uma cápsula contendo placebo ou Etodolaco, sendo que na segunda sessão recebiam tratamento diferente da primeira (desenho crossover). A sequência de tratamento foi randomizada previamente ao inicio da pesquisa. Aplicou-se um questionário de ansiedade (Escala de Corah) e a avaliação inicial de sensibilidade foi realizada através de uma escala visual (EVA) e uma escala verbal (EVR). O clareamento foi realizado com peróxido de hidrogênio a 35% (Whiteness HP Blue, FGM, Joinvile, SC, Brasil) por 40 minutos, em duas sessões com intervalo de uma semana. O nível de sensibilidade foi mensurado antes, durante (20’ e 40’) e 24 horas após o procedimento clareador usando a EVA e EVR. A alteração de cor dos elementos dentais foi mensurada através do sistema CieLab (com espectrofotômetro Easy Shade) e da escala Vita Bleach Guide, nos tempos: inicial e uma semana após cada procedimento de clareamento dental. Os dados referentes a escala de clareamento foram analisados considerando as médias de pontuação observada no início do estudo e após cada sessão; e as diferenças (delta) entre duas medições consecutivas. Diferenças sobre presença/ ausência de sensibilidade foram analisados pelo teste exato de Fisher, e as escalas de avaliação da sensibilidade dental, o teste de Mann-Whitney. Para ambas as escalas de avaliação da sensibilidade dental, os dados dos escores em cada momento de avaliação/ sessão de clareamento, foram submetidos ao teste de Mann-Whitney. Os resultados demonstraram que, apenas com a EVA, na segunda sessão, houve alguma diferença estatística, no entanto, não conseguiu eliminar ou diminuir a sensibilidade entre os tratamentos nos tempos avaliados. Houve um clareamento efetivo para ambos os grupos, com uma variação de 8,4 para 3,7 na escala Bleach Guide, e de de 9,5 a 10,1 para o Easy Shade. O risco e nível de sensibilidade trans e pós clareamento dental de consultório, no geral, não foram eliminados com o uso preemptivo do Etodolaco ao procedimento clareador

Self-organized Vortex State in Two-dimensional Dictyostelium Dynamics

We present results of experiments on the dynamics of Dictyostelium discoideum in a novel set-up which constraints cell motion to a plane. After aggregation, the amoebae collect into round ''pancake" structures in which the cells rotate around the center of the pancake. This vortex state persists for many hours and we have explicitly verified that the motion is not due to rotating waves of cAMP. To provide an alternative mechanism for the self-organization of the Dictyostelium cells, we have developed a new model of the dynamics of self-propelled deformable objects. In this model, we show that cohesive energy between the cells, together with a coupling between the self-generated propulsive force and the cell's configuration produces a self-organized vortex state. The angular velocity profiles of the experiment and of the model are qualitatively similar. The mechanism for self-organization reported here can possibly explain similar vortex states in other biological systems.Comment: submitted to PRL; revised version dated 3/8/9

Community-driven dispersal in an individual-based predator-prey model

We present a spatial, individual-based predator-prey model in which dispersal is dependent on the local community. We determine species suitability to the biotic conditions of their local environment through a time and space varying fitness measure. Dispersal of individuals to nearby communities occurs whenever their fitness falls below a predefined tolerance threshold. The spatiotemporal dynamics of the model is described in terms of this threshold. We compare this dynamics with the one obtained through density-independent dispersal and find marked differences. In the community-driven scenario, the spatial correlations in the population density do not vary in a linear fashion as we increase the tolerance threshold. Instead we find the system to cross different dynamical regimes as the threshold is raised. Spatial patterns evolve from disordered, to scale-free complex patterns, to finally becoming well-organized domains. This model therefore predicts that natural populations, the dispersal strategies of which are likely to be influenced by their local environment, might be subject to complex spatiotemporal dynamics.Comment: 43 pages, 7 figures, vocabulary modifications, discussion expanded, references added, Ecological Complexity accepte

Efeito De Técnicas De Polimento Na Estabilidade Da Cor E Rugosidade Superficial De Resinas Compostas Microhibridas

Resin roughness and staining is a common problem in dentistry. Objective: the aim of this study was to verify the influence of single and multiple-steps polishing techniques on color stability and surface roughness of differents composite resins. Groups were (n=10): FS+CS. Filtek Supreme XT + clear strip; FS+PG. Filtek Supreme XT+PoGo; FS+SF. Filtek Supreme XT+Sof-Lex; AM+CS. Amelogen+clear strip; AM+PG. Amelogen+PoGo; AM+SF. Amelogen+Sof-Lex; TEC+CL. TetricEvoCeram + clear strip; TEC+PG. Tetric EvoCeram+PoGo; TEC+SF. Tetric EvoCeram+Sof-Lex; CED+CS. Ceram X Duo+clear strip; CED+PG. Ceram X Duo+PoGo; CED+SF. Ceram X Duo+ Sof-Lex. The initial color and roughness were determined before and after the polishing procedures. All specimens were stored for 7 days in coffee solution and the color assessment was performed. Two specimens from each group were evaluated by scanning electron microscopy. Roughness and color data were submitted to ANOVA and Tukey tests(pG7(5.8f)=G10(5.7ef)>G1(3.7c), followed by the G6(5.9f)>G9(3.1bc)=G12(2.1ab)>G3(1.7a). G3, after 7 days, presented the lowest values for Delta E(1.704). The lowest roughness values were observed when the clear strips were used regardless material type. The Sof-Lex system provided the lowest surface roughness values for all tested composite resins. Among composite resins the highest roughness values were found for Amelogen (G5-0.49 and G6-0.35), regardless polishing technique. All tested materials presented changes in color after immersion in coffee solution. The roughness surface and the staining of composite resins are material and polishing technique dependents.32126227

Preemptive use of etodolac on tooth sensitivity after in-office bleaching: a randomized clinical trial

Abstract Purpose: This study determined the effectiveness of the preemptive administration of etodolac on risk and intensity of tooth sensitivity and the bleaching effect caused by in-office bleaching using 35% hydrogen peroxide. Material and methods: Fifty patients were selected for this tripleblind, randomized, crossover, and placebo-controlled clinical trial. Etodolac (400 mg) or placebo was administrated in a single-dose 1 hour prior to the bleaching procedure. The whitening treatment with 35% hydrogen peroxide was carried out in two sessions with a 7-day interval. Tooth sensitivity was assessed before, during, and 24 hours after the procedure using the analog visual scale and the verbal rating scale. Color alteration was assessed by a bleach guide scale, 7 days after each session. Relative risk of sensitivity was calculated and adjusted by session, while overall risk was compared by the McNemar's test. Data on the sensitivity level of both scales and color shade were subjected to Friedman, Wilcoxon, and Mann-Whitney tests, respectively (α=0.05). Results: The preemptive administration of etodolac did not affect the risk of tooth sensitivity and the level of sensitivity reported, regardless of the time of evaluation and scale used. The sequence of treatment allocation did not affect bleaching effectiveness, while the second session resulted in additional color modification. The preemptive administration of etodolac in a single dose 1 hour prior to in-office tooth bleaching did not alter tooth color, and the risk and intensity of tooth sensitivity reported by patients. Conclusion: A single-dose preemptive administration of 400 mg of etodolac did not affect either risk of tooth sensitivity or level of sensitivity reported by patients, during or after the in-office tooth bleaching procedure

Polishing techniques effect on microhybrid, nanohybrid and nanofilled composites color and surface roughness stability

Resin roughness and staining is a common problem in dentistry. Objective: the aim of this study was to verify the influence of single and multiple-steps polishing techniques on color stability and surface roughness of differents composite resins. Groups were (n=10): FS+CS. Filtek Supreme XT + clear strip; FS+PG. Filtek Supreme XT+PoGo; FS+SF. Filtek Supreme XT+Sof-Lex; AM+CS. Amelogen+clear strip; AM+PG. Amelogen+PoGo; AM+SF. Amelogen+Sof-Lex; TEC+CL .TetricEvoCeram + clear strip; TEC+PG .Tetric EvoCeram+ PoGo; TEC+SF .Tetric EvoCeram+Sof-Lex; CED+CS .Ceram X Duo+clear strip; CED+PG. Ceram X Duo+PoGo; CED+SF. Ceram X Duo+Sof-Lex. The initial color and roughness were determined before and after the polishing procedures. All specimens were stored for 7 days in coffee solution and the color assessment was performed. Two specimens from each group were evaluated by scanning electron microscopy. Roughness and color data were submitted to ANOVA and Tukey tests(pG7(5.8f)=G10(5.7ef)>G1(3.7c), followed by the G6(5.9f)>G9(3.1bc)=G12(2.1ab)>G3(1.7a). G3, after 7 days, presented the lowest values for ΔE(1.704). The lowest roughness values were observed when the clear strips were used regardless material type. The Sof-Lex system provided the lowest surface roughness values for all tested composite resins. Among composite resins the highest roughness values were found for Amelogen (G5-0.49 and G6-0.35), regardless polishing technique. All tested materials presented changes in color after immersion in coffee solution. The roughness surface and the staining of composite resins are material and polishing technique dependents

Concurrent Proinflammatory and Apoptotic Activity of a Helicobacter pylori Protein (HP986) Points to Its Role in Chronic Persistence

Helicobacter pylori induces cytokine mediated changes in gastroduodenal pathophysiology, wherein, the activated macrophages at the sub-mucosal space play a central role in mounting innate immune response against the antigens. The bacterium gains niche through persistent inflammation and local immune-suppression causing peptic ulcer disease or chronic gastritis; the latter being a significant risk factor for the development of gastric adenocarcinoma. What favors persistence of H. pylori in the gastric niches is not clearly understood. We report detailed characterization of a functionally unknown gene (HP986), which was detected in patient isolates associated with peptic ulcer and gastric carcinoma. Expression and purification of recombinant HP986 (rHP986) revealed a novel, ∼29 kDa protein in biologically active form which associates with significant levels of humoral immune responses in diseased individuals (p<0.001). Also, it induced significant levels of TNF-α and Interleukin-8 in cultured human macrophages concurrent to the translocation of nuclear transcription factor-κB (NF-κB). Further, the rHP986 induced apoptosis of cultured macrophages through a Fas mediated pathway. Dissection of the underlying signaling mechanism revealed that rHP986 induces both TNFR1 and Fas expression to lead to apoptosis. We further demonstrated interaction of HP986 with TNFR1 through computational and experimental approaches. Independent proinflammatory and apoptotic responses triggered by rHP986 as shown in this study point to its role, possibly as a survival strategy to gain niche through inflammation and to counter the activated macrophages to avoid clearance