Objective: To evaluate the in vitro changes on the enamel surface after a micro-abrasion treatment promoted by different products. Material and Methods: Fifty (50) fragments of bovine enamel (15 mm × 5 mm) were randomly assigned to five groups (n=10) according to the product utilized: G1 (control)= silicone polisher (TDV), G2= 37% phosphoric acid (3M/ESPE) + pumice stone (SS White), G3= Micropol (DMC Equipment), G4= Opalustre (Ultradent) and G5= Whiteness RM (FGM Dental Products). Roughness and wear were the responsible variables used to analyze these surfaces in four stages: baseline, 60 s and 120 s after the micro-abrasion and after polishing, using a Hommel Tester T1000 device. After the tests, a normal distribution of data was verified, with repeated ANOVA analyses (p≤0.05) which were used to compare each product in different stages. One-way ANOVA and Tukey tests were applied for individual comparisons between the products in each stage (p≤0.05). Results: Means and standard deviations of roughness and wear (µm) after all the promoted stages were: G1=7.26(1.81)/13.16(2.67), G2=2.02(0.62)/37.44(3.33), G3=1.81(0.91)/34.93(6.92), G4=1.92(0.29)/38.42(0.65) and G5=1.98(0.53)/33.45(2.66). At 60 seconds, all products tended to produce less surface roughness with a variable gradual decrease over time. After polishing, there were no statistically significant differences between the groups, except for G1. Independent of the product utilized, the enamel wear occurred after the micro-abrasion. Conclusions: In this in vitro study, enamel micro-abrasion presented itself as a conservative approach, regardless of the type of the paste compound utilized. These products promoted minor roughness alterations and minimal wear. The use of phosphoric acid and pumice stone showed similar results to commercial products for the micro-abrasion with regard to the surface roughness and wear.

OBJECTIVES: Nanofilled composite resins are claimed to provide superior mechanical properties compared with microhybrid resins. Thus, the aim of this study was to compare nanofilled with microhybrid composite resins. The null hypothesis was that the size and the distribution of fillers do not influence the mechanical properties of surface roughness and wear after simulated toothbrushing test. MATERIAL AND METHODS: Ten rectangular specimens (15 mm x 5 mm x 4 mm) of Filtek Z250 (FZ2), Admira (A), TPH3 (T),Esthet-X (EX), Estelite Sigma (ES), Concept Advanced (C), Grandio (G) and Filtek Z350 (F) were prepared according to manufacturer's instructions. Half of each top surface was protected with nail polish as control surface (not brushed) while the other half was assessed with five random readings using a roughness tester (Ra). Following, the specimens were abraded by simulated toothbrushing with soft toothbrushes and slurry comprised of 2:1 water and dentifrice (w/w). 100,000 strokes were performed and the brushed surfaces were reanalyzed. Nail polish layers were removed from the specimens so that the roughness (Ra) and the wear could be assessed with three random readings (µm). Data were analyzed by ANOVA and Tukey's multiple-comparison test (α=0.05). RESULTS: Overall outcomes indicated that composite resins showed a significant increase in roughness after simulated toothbrushing, except for Grandio, which presented a smoother surface. Generally, wear ofnanofilled resins was significantly lower compared with microhybrid resins. CONCLUSIONS: As restorative materials suffer alterations under mechanical challenges, such as toothbrushing, the use of nanofilled materials seem to be more resistant than microhybrid composite resins, being less prone to be rougher and worn.

Objetivo: As lesões de isquemia-reperfusão (I/R) são uma forma de inflamação aguda na qual os leucócitos são considerados como tendo um papel fundamental. Este estudo foi feito com o objetivo de determinar se o bloqueio das Moléculas de Adesão Intercelular -1 (ICAM-1), envolvidas na diapedese dos leucócitos, é eficaz em minimizar estas lesões na musculatura esquelética dos membros posteriores de ratos. Métodos: A aorta infra-renal de três grupos de seis ratos adultos foi clampeada por seis horas. Logo após, um grupo foi sacrificado (grupo controle) e os outros foram submetidos a 24 horas de reperfusão, um com solução salina fisiológica 0,9% (grupo reperfusão) e outro com anticorpos monoclonais anti-ICAM-1 (grupo ICAM-1). A quantificação da enzima mieloperoxidase foi utilizada para estimar o infiltrado de leucócitos na musculatura. Biópsias foram obtidas e coradas com hematoxilina-eosina e NADH. Amostras de sangue foram obtidas e parâmetros bioquímicos foram analisados (creatinina; potássio; DHL; leucograma; pH venoso, CK). Resultados: Os níveis de mieloperoxidase foram aumentados nos grupos reperfusão (p<0,001) e ICAM-1 (p<0,019) em relação ao grupo controle. A atividade oxidativa das fibras musculares foi aumentada de maneira significativa nos grupos submetidos a reperfusão. Os outros parâmetros não apresentaram diferenças significativas. Conclusões: A lesão de reperfusão foi de maior magnitude que a lesão isquêmica. Houve aumento da atividade oxidativa e do infiltrado inflamatório com a reperfusão, não se observando necrose significativa da musculatura com o microscópio óptico. O bloqueio de ICAM-I diminuiu o infiltrado inflamatório mas não o aumento da atividade oxidativa observado com a reperfusão.

Purpose: Ischemia-reperfusion lesions are a form of acute inflammation in which leukocytes are considered to play a pivotal role. This study was made with the objective of determining whether the blockage of intracellular adhesion molecule-1, involved in the diapedesis of leukocytes, is efficacious in minimizing this lesions in the skeletal musculature of the posterior limbs of rats. Methods: The juxta-infrarenal aorta of three groups of six adult rats was clipped for six hours. After this, one group was sacrificed (control group) and the others underwent 24 hours of reperfusion, one with 0.9% physiological saline (reperfusion group) and the other with anti-ICAM-1 monoclonal antibodies (ICAM-1 group). A myeloperoxidase assay was utilized for estimating the infiltrate of neutrophils. Biopsies were obtained to make thin sections of hematoxylin-eosin and NADH. Blood samples were collected for making assays of biochemical parameters (creatinine; potassium; DHL; leukogram; venous pH; CK). Results: The myeloperoxidase levels were raised in the reperfusion (p < 0.001) and ICAM-1 (p < 0.019) groups in relation to the control group. The oxidative activity of the muscle fibers was significantly raised in the groups that underwent reperfusion. The other parameters did not present significant differences. Conclusions: The reperfusion lesion was bigger than the ischemic lesion. There was an increase in oxidative activity and inflammatory infiltrate with the reperfusion, without significant muscle necrosis being seen under the optical microscope. The blockage of ICAM-1 diminished the inflammatory infiltrate but not the rise in oxidative activity observed with the reperfusion.