Influence of Finishing and Polishing Techniques and Abrasion on Transmittance and Roughness of Composite Resins.

The aim of this study was to evaluate the influence of finishing and polishing systems and toothbrush abrasion on transmittance (T) and surface roughness (Ra) of three composite resins (Filtek Z350 XT, Tetric N-Ceram, and IPS Empress Direct). Eighteen resin disks (10 mm diameter × 2 mm thick) finished by polyester strips had initial surface smoothness recorded, representing phase 1 (P1). Specimens were divided into three groups (n=6) according to the finishing/polishing instrument used (OneGloss, TopGloss, and Sof-Lex) to compose phase 2 samples (P2). Then specimens were subjected to 514 cycles of toothbrush simulation using a toothpaste slurry, with a constant load applied to soft bristles, and were then washed (phase 3=P3). After each phase, the specimens were examined by an optical profiler and spectrophotometer to measure Ra and T. Data were analyzed by analysis of variance, Tukey and Pearson tests. T values were statistically influenced by composite resin ( p=0.000) and phase of measurement ( p=0.000) factors, while the finishing/polishing system used ( p=0.741) did not affect T. On the other hand, Ra values were statistically affected by the factor finishing/polishing system ( p=0.000), but not by composite resin ( p=0.100) and phase of measurement ( p=0.451). Tetric N-Ceram and Empress Direct presented higher values of roughness when polished by OneGloss, while TopGloss and Sof-Lex showed a lower roughness. It can be concluded that composite resins transmitted more light after dental abrasion. Transmittance of composite resins was not modified by the distinct roughness created by finishing/polishing instruments.

Sucrose substitutes affect the cariogenic potential of Streptococcus mutans biofilms.

Streptococcus mutans is considered the primary etiologic agent of dental caries and contributes significantly to the virulence of dental plaque, especially in the presence of sucrose. To avoid the role of sucrose on the virulence factors of S. mutans, sugar substitutes are commonly consumed because they lead to lower or no production of acids and interfere with biofilm formation. This study aimed to investigate the contribution of sugar substitutes in the cariogenic potential of S. mutans biofilms. Thus, in the presence of sucrose, glucose, sucralose and sorbitol, the biofilm mass was quantified up to 96 h, the pH of the spent culture media was measured, the expression of biofilm-related genes was determined, and demineralization challenge experiments were conduct in enamel fragments. The presence of sugars or sugar substitutes profoundly affected the expression of spaP, gtfB, gtfC, gbpB, ftf, vicR and vicX in either biofilm or planktonic cells. The substitution of sucrose induced a down-regulation of most genes involved in sucrose-dependent colonization in biofilm cells. When the ratio between the expression of biofilm and planktonic cells was considered, most of those genes were down-regulated in biofilm cells in the presence of sugars and up-regulated in the presence of sugar substitutes. However, sucralose but not sorbitol fulfilled the purpose of reducing the cariogenic potential of the diet since it induced the biofilm formation with the lowest biomass, did not change the pH of the medium and led to the lowest lesion depth in the cariogenic challenge.

Avaliação do alinhamento postural e do desempenho em atividades funcionais de crianças hemofílicas em idade inferior a sete anos, com e sem sinovite crônica: correlação com a incidência de hemartroses / Evaluation of postural alignment and performance in functional activities among hemophilic children under 7 years old with and without chronic synovitis: correlation with hemarthrosis incidence

INTRODUÇÃO: A sinovite na hemofilia pode induzir às alterações nos receptores sensitivos e proprioceptivos articulares. Tal efeito favorece a redução de estabilidade e um desalinhamento corporal, podendo comprometer a funcionalidade das crianças acometidas. OBJETIVO: Avaliar o alinhamento postural dos membros inferiores e o desempenho funcional de crianças hemofílicas, relacionando-os com a incidência de hemartroses. MÉTODO: Foi avaliado um grupo experimental (GE) de 28 crianças hemofílicas e um grupo controle (GC) de 20 crianças sem hemofilia. O GE foi dividido de acordo com o grau de comprometimento articular: 16 crianças no grupo sem sinovite crônica (GSS) e 12 no grupo com sinovite crônica (GCS). Cada grupo foi subdividido por faixa etária: 3-4 anos, 5-6 anos, 7 anos. A avaliação consistiu da análise do alinhamento dos ângulos do joelho e do tornozelo através do programa Geometer Sketchpad. O desempenho das atividades funcionais foi avaliado através de testes modificados a partir do Exame Neurológico Evolutivo de Lefévre. RESULTADOS: Foi constatado que a média dos sangramentos dos hemofílicos aumenta com a idade (p< 0,001) e parece ser relacionada com o grau de comprometimento articular (GCS>GSS), (p< 0,059); o ângulo do joelho do GCS tende a um menor valor (semiflexão) quando comparado aos outros grupos; e há diferença significativa no percentual de desempenho nos testes entre grupos na faixa etária de 7 anos (GSS>GC e GSS>GCS), (p< 0,087). DISCUSSÃO E CONCLUSÃO: Crianças hemofílicas de 7 anos apresentaram menor desempenho funcional quando comparadas aos outros grupos. Este resultado ressalta a importância da fisioterapia precoce associada à terapêutica médica para evitar comprometimentos articulares severos.

Acute fluoxetine administration differentially affects brain C-Fos expression in fasted and refed rats.

In the present study we investigated the effect of acute fluoxetine administration on the expression of c-Fos in the rat brain under two different metabolic conditions: fed and fasting states. Wistar male rats, weighing 220+/-30g, received i.p. injections of saline solution or fluoxetine (10mg/kg), and were killed 2 h later. The brains were removed after transcardiac perfusion with phosphate-buffered saline followed by paraformaldehyde, and were then processed for immunohistochemistry. Fos-like immunoreactivity was quantified by a computerized system. Fasted animals faced an 18-h suppression of food intake, while fed groups were submitted to an initial 14-h period of fast followed by a 4-h period in which food was freely available. Both in fasting and fed states, fluoxetine-treated animals presented a significant increase in c-Fos expression in hypothalamic areas, limbic structures, circumventricular areas, and in mesencephalic and rhomboencephalic regions, as compared with saline-treated controls. The quantitative comparison of data obtained from fasted and fed animals showed that fasted rats treated with fluoxetine presented a higher c-Fos expression in the ventromedial hypothalamus and the paraventricular nuclei compared with the fed group, while in fluoxetine-treated fed rats c-Fos expression was higher in the arcuate nuclei, medial amygdala, locus coeruleus and dorsal raphe nuclei, as compared with fasted, fluoxetine-treated animals. These data indicate that the metabolic condition of the animals significantly modifies fluoxetine-induced brain c-Fos expression, suggesting that visceral and behavioral fluoxetine effects may be influenced by the metabolic state of the individual.