ABSTRACT
Color stability is among the most frequent causes of restoration failures, and influences surface properties. Aim: The aim of this study was to investigate the influence of pigment solutions on low-shrinkage and conventional composites regarding changes in the physical properties of composite surfaces. Materials and Method: Specimens of four composites (Filtek Z350 XT, Point 4, N'Durance and Venus Diamond) were randomly distributed into three groups to be submitted to each of three pigment solutions (red wine, tomato sauce and coffee) in fifteen-minute daily cycles, for twenty-eight days. There were 12 groups altogether (n = 10). Color, surface roughness and hardness tests were performed. Statistical analysis includedAnalysis of variance (ANOVA) and Tukey's significance test (a = 0.05). Results: Color changes caused by the solutions did not differ significantly among Filtek Z350 XT, Venus Diamond and N'Durance. Hardness decreased significantly in Filtek Z350 XT and Venus Diamond after chemical challenge with each solution. For the composite independent factor, roughness was highest in Venus Diamond, followed by Filtek Z350 XT, Point 4 and N'Durance. Conclusions: Treatment with different pigment solutions (red wine, tomato sauce or coffee) increased stainability and decreased hardness of both low-shrinkage and conventional composites, while roughness was unaffected.
A estabilidade de cor está entre as causas mais frequentes de falhas de restauragoes, que também influenciam suas propriedades superficiais. Objetivo: O objetivo do presente estudo foi investigar a influencia de solugoes de pigmentos em compósitos convencionais e de baixa retragao, bem como alteragoes naspropriedades físicas da superficie dos compósitos. Materiais eMétodo: Amostras de cada compósito (Filtek Z350XT, Point 4, N'Durance e Venus Diamond) foram distribuidas aleatoriamente em grupos submetidos a cada solugao pigmentante (vinho tinto, molho de tomate e café) em ciclos diários de quinze minutos, durante vinte e oito dias. Assim, totalizando 12 grupos (n = 10). Foram realizados testes de cor, rugosidade superficial e dureza. A Análise Estatistica foi realizada usando Análise de variáncia (ANOVA) e o teste de significáncia de Tukey (a = 0.05). Resultados: As alteragoes de cor desencadeadas pelas solugoes investigadas nao mostraram diferenga estatisticamente significativa entre os compósitos Filtek Z350 XT, Venus Diamond e N'Durance. Os valores de dureza registrados para Filtek Z350XT e Venus Diamond diminuiram significativamente após o desafio químico com cada uma das solugoes pigmentantes. Para o fator independente compósito, Venus Diamond registrou a maior rugosidade; foi seguido por Filtek Z350XT, Point 4 e N'Durance. Conclusoes: Os tratamentos das amostras com diferentes solugoes pigmentantes (vinho tinto, molho de tomate e café) aumentaram a manchabilidade dos compósitos convencionais e de baixa retragao e diminuiram sua dureza, embora nao tenham afetado a rugosidade dos compósitos.
Subject(s)
Coffee , Diamond , Hardness , Surface PropertiesABSTRACT
ABSTRACT Color stability is among the most frequent causes of restoration failures, and influences surface properties. Aim: The aim of this study was to investigate the influence of pigment solutions on low-shrinkage and conventional composites regarding changes in the physical properties of composite surfaces. Materials and Method: Specimens of four composites (Filtek Z350 XT, Point 4, N'Durance and Venus Diamond) were randomly distributed into three groups to be submitted to each of three pigment solutions (red wine, tomato sauce and coffee) in fifteen-minute daily cycles, for twenty-eight days. There were 12 groups altogether (n = 10). Color, surface roughness and hardness tests were performed. Statistical analysis includedAnalysis of variance (ANOVA) and Tukey's significance test (a = 0.05). Results: Color changes caused by the solutions did not differ significantly among Filtek Z350 XT, Venus Diamond and N'Durance. Hardness decreased significantly in Filtek Z350 XT and Venus Diamond after chemical challenge with each solution. For the composite independent factor, roughness was highest in Venus Diamond, followed by Filtek Z350 XT, Point 4 and N'Durance. Conclusions: Treatment with different pigment solutions (red wine, tomato sauce or coffee) increased stainability and decreased hardness of both low-shrinkage and conventional composites, while roughness was unaffected.
RESUMO A estabilidade de cor está entre as causas mais frequentes de falhas de restauragoes, que também influenciam suas propriedades superficiais. Objetivo: O objetivo do presente estudo foi investigar a influencia de solugoes de pigmentos em compósitos convencionais e de baixa retragao, bem como alteragoes naspropriedades físicas da superficie dos compósitos. Materiais eMétodo: Amostras de cada compósito (Filtek Z350XT, Point 4, N'Durance e Venus Diamond) foram distribuidas aleatoriamente em grupos submetidos a cada solugao pigmentante (vinho tinto, molho de tomate e café) em ciclos diários de quinze minutos, durante vinte e oito dias. Assim, totalizando 12 grupos (n = 10). Foram realizados testes de cor, rugosidade superficial e dureza. A Análise Estatistica foi realizada usando Análise de variáncia (ANOVA) e o teste de significáncia de Tukey (a = 0.05). Resultados: As alteragoes de cor desencadeadas pelas solugoes investigadas nao mostraram diferenga estatisticamente significativa entre os compósitos Filtek Z350 XT, Venus Diamond e N'Durance. Os valores de dureza registrados para Filtek Z350XT e Venus Diamond diminuiram significativamente após o desafio químico com cada uma das solugoes pigmentantes. Para o fator independente compósito, Venus Diamond registrou a maior rugosidade; foi seguido por Filtek Z350XT, Point 4 e N'Durance. Conclusoes: Os tratamentos das amostras com diferentes solugoes pigmentantes (vinho tinto, molho de tomate e café) aumentaram a manchabilidade dos compósitos convencionais e de baixa retragao e diminuiram sua dureza, embora nao tenham afetado a rugosidade dos compósitos.
ABSTRACT
BACKGROUND: The terms sedentary behavior and physical inactivity have been confusingly mixed. Although the association between physical inactivity and mortality has been shown previously in subjects with COPD, this association had not yet been investigated with regard to sedentarism. The aim of this work was to investigate the impact of sedentary behavior on mortality of subjects with COPD and to propose a cutoff point of sedentarism with prognostic value. METHODS: In this retrospective cohort study, sedentary behavior was assessed with 2 activity monitors (DynaPort and Sensewear armband) in 101 subjects with COPD from 2006 to 2011. Vital status was then ascertained in 2015. The following 6 variables of sedentary behavior were analyzed: average of metabolic equivalent of task (MET)/d (reflecting intensity); time spent/d lying, sitting, and lying + sitting (reflecting duration of sedentary postures); and time spent/d in activities requiring <1.5 MET and <2 MET (reflecting intensity and duration of sedentary time). Cutoff points for sedentarism and their respective prognostic values were investigated for each variable. RESULTS: Forty-one subjects (41%) died over a median (interquartile range) follow-up period of 62 (43-88) months. After adjusting for potential confounders in the Cox regression model, cutoff points from variables that combine duration of sedentary time and intensity <1.5 MET or <2 MET were associated with the increased risk of mortality. The strongest independent cutoff for predicting mortality was ≥8.5 h/d spent in sedentary activities <1.5 MET (area under the curve 0.76; hazard ratio 4.09, 95% CI 1.90-8.78; P < .001). CONCLUSIONS: Sedentary behavior was an independent predictor of mortality in subjects with COPD, even adjusting for moderate-to-vigorous physical activity and a number of other variables. Mortality was higher in subjects with COPD who spend ≥8.5 h/d in activities requiring <1.5 MET. These findings may open room for future studies aiming at decreasing sedentary time as a promising strategy to reduce mortality risk in subjects with COPD.
Subject(s)
Pulmonary Disease, Chronic Obstructive/mortality , Sedentary Behavior , Aged , Exercise/physiology , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prognosis , Proportional Hazards Models , Pulmonary Disease, Chronic Obstructive/physiopathology , Retrospective Studies , Risk Factors , Time FactorsABSTRACT
BACKGROUND: Studies have shown that individuals with COPD have impaired body balance, probably caused by the disease's multisystemic manifestations plus age-related decline in balance, potentially increasing the risk of falling and its consequences. However, little is known about the profile of individuals with COPD who present balance impairments, especially related to sex and disease severity stages. The aim of this work was to compare static and functional balance between subjects with COPD and healthy controls and to check possible differences according to sex and degrees of disease severity. METHODS: Forty-seven subjects with COPD and 25 healthy controls were included in this study. Their static balance was assessed in one-legged stance using a force platform and functional balance with the Timed Up and Go test. Additionally, participants performed spirometry, the 6-min walk test and isometric quadriceps maximal voluntary contraction assessment. Disease severity was classified according to the Global Initiative for Obstructive Lung Disease stages and BODE (body mass index, air-flow obstruction, dyspnea, and exercise capacity) scores. RESULTS: In comparison with healthy controls, subjects with COPD had worse static (center of pressure displacement area: 9.3 ± 1.9 cm2 vs 11.6 ± 4.0 cm2, respectively, P = .01) and functional balance (Timed Up and Go test: 8.5 ± 1.3 s vs 10.3 ± 1.8 s, respectively, P < .001). In the COPD group, men performed better in the Timed Up and Go test than women (9.8 ± 1.2 s vs 10.9 ± 2.2 s, respectively, P = .03), whereas women presented a better static balance in comparison with men for all parameters related to center of pressure (P < .005 for all). Disease severity did not affect any balance results. CONCLUSIONS: Individuals with COPD had worse static and functional balance in comparison with healthy controls. Sex can mediate these results, depending on the type of balance evaluation (force platform or functional test). Balance performance was similar among the groups classified according to disease severity.
