ABSTRACT
OBJECTIVES: This study aimed to evaluate the desensitizing effect of a prefilled disposable tray containing potassium nitrate and fluoride on the self-reported tooth sensitivity (TS) and the bleaching efficacy of 40% hydrogen peroxide bleaching agent used for in-office bleaching in comparison with potassium nitrate and fluoride gel applied in a conventional-delivered tray system in an equivalence clinical trial. METHODS AND MATERIALS: Seventy-eight patients, with a right maxillary canine darker than A3, were selected for this single-blind (evaluators), randomized clinical trial. Teeth were bleached in two sessions with a one-week interval in between. Before in-office bleaching, the prefilled disposable tray or conventional tray containing potassium nitrate and fluoride was used for 15 minutes. Subsequently, the bleaching agent was applied in two 20-minute applications (per the manufacturer's directions) in each session. The color change was evaluated by subjective (Vita Classical and Vita Bleachedguide) and objective (Easyshade Advance Spectrophotometer) methods at baseline and 30 days after the first bleaching session. TS was recorded for up to 48 hours using a 0-10 visual analog scale. The absolute risk was evaluated by chi-square test, while the intensity of TS was evaluated by McNemar test (α=0.05). Color change in shade guide units and ΔE was analyzed by Student t-test for independent samples (α=0.05). RESULTS: Significant whitening was observed in both groups after 30 days of clinical evaluation. The use of different methods of desensitizer in a tray did not influence the absolute risk and intensity of TS (p>0.05), although a tendency of lower risk of TS with the prefilled disposable tray containing potassium nitrate and fluoride was observed. CONCLUSION: The use of a prefilled disposable tray containing potassium nitrate and fluoride before the application of the in-office bleaching product did not affect the whitening degree and decreased self-reported TS when compared with a conventional-delivered tray system.
Subject(s)
Dentin Sensitivity , Tooth Bleaching Agents , Tooth Bleaching , Tooth Discoloration , Humans , Hydrogen Peroxide , Single-Blind Method , Treatment OutcomeABSTRACT
Several fruit trees are able to cope with iron (Fe) deficiency when grown in calcareous soils in the Mediterranean region, although information regarding well adapted slow-growing species is scarce, and the mechanisms activated by these species are not described in the literature. A crucial issue related to tolerance is the need to transport Fe over relatively long distances inside the plant. To evaluate the possible role of organic acids in the movement of Fe in tolerant plants, we studied the concentration of low molecular weight organic acids in several organs of 1-year old carob plants grown for 55 days in nutrient solutions without Fe (0µM Fe) or with 1µM Fe and 10µM Fe. Roots, stems and leaves were harvested, and the biomass, Fe and organic acid contents quantified. Total leaf chlorophyll (Chl) was evaluated in young leaves over the experimental period and the activity of root ferric chelate-reductase (FC-R; EC 1.16.1.17) was determined after 35 days, when deficiency symptoms appeared. Iron chlorosis was observed only at the end of the experiment in plants grown in the absence of Fe, and these plants had a smaller DW of leaves and also significant greater activity of root FC-R. Iron deficiency (Fe0 and Fe1 treatments) induced significant changes in the concentrations of succinic, malic, citric and fumaric acids, which increased in roots, or in basal, middle and apical leaves. There were significant correlations between most organic acids (with the exceptions of 2-oxoglutaric and tartaric acids) and leaf Chl. Analysis of each type of leaf showed that more succinic and malic acids were present in young chlorotic leaves while the reverse was true for quinic acid. These changes in organic acids followed a root-to-foliage pathway that was similar in all leaf types and particularly evident in young chlorotic leaves. We hypothesised that it was associated with Fe transport from roots to aboveground tissues, as there were significant differences in Fe contents between treatments with and without Fe.
ABSTRACT
A síndrome clínica da diabetes caracterizada pela redução da capacidade de metabolização de carboidratos e gorduras, resultando em aumento dos níveis séricos de glicose (hiperglicemia) e lipídios (hiperlipidemia), acarretando em degeneração vascular prematura. O objetivo do presente trabalho foi testar os efeitos da antocianina e do própolis ministrados nas doses de 20mg e 150mg, respectivamente, em coelhos diabéticos para a verificação dos efeitos sobre os níveis de glicose e triacilglicerol. Os grupos experimentais de coelhos estudados foram: Grupo 1- grupo controle que somente recebeu ração; Grupo 2- grupo diabético que recebeu ração mais aloxano; Grupo 3- grupo diabético que recebeu ração, aloxano e 1 c psula de antocianina (20mg) diariamente; Grupo 4- grupo diabético que recebeu ração, aloxano e 1 c psula de própolis (150mg) diariamente. Os Grupos 3 e 4 foram submetidos a vinte e oito dias de tratamento, com dosagem semanal dos níveis sanguíneos de glicose e de triacilglicerol. De acordo com os resultados obtidos, pode-se observar que, durante todo o período experimental, a antocianina foi mais eficaz, em induzir a queda dos níveis de glicose, com reduções de 10,78 por cento aos 7 dias, 10,54 por cento aos 14 dias, 17,33 por cento aos 21 dias e 28,09 por cento aos 28 dias. J o própolis apresentou redução de 22,69 por cento aos 28 dias. Observou-se redução dos percentuais de variação de triacilgliceróis em 22,74 por cento pela antocianina e 22,60 por cento pelo tratamento com própolis aos 28 dias. Ao se compararem os Grupos 3 e 4 com o Grupo 2 (aloxano) durante todo o período experimental, os níveis de triacilgliceróis aumentaram no período de O a 21 dias
