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Background@#As the importance of the esthetic function of teeth increases, the use of esthetic restoration materials and whitening treatment are increasing. The purpose of this study was to investigate the color change of esthetic restoration materials upon using staining and whitening toothpaste. @*Methods@#Light curing (LC) packable composite resin, LC flowable resin, LC glass ionomer (GI), and self-curing GI specimens were colored in coffee or curry for three hours a day for seven days. After that, regular toothpaste, whitening toothpaste containing hydrogen peroxide, and whitening toothpaste containing activated charcoal were applied for three minutes three times a day for two weeks. Luminosity (L), chromaticity a (a), and chromaticity b (b) were measured using a spectrophotometer once a week. @*Results@#In the coffee-colored group, the change in L2 *a2 *b2 (E2 ) with time was significant (p=0.004), there was no difference for different toothpaste types (p=0.646), and there was significant difference (p＜0.001) for different esthetic restorative materials.The change of E2 in the curry-colored group was significant only for different esthetic restorative materials (p＜0.001). In the coffee-colored group, the L, a, and b values of the light-curing GI showed greater change than other materials after staining and one week after whitening, turning dark, red, and yellow. In the curry-colored group, L did not differ for different materials and times, and a and b showed the greatest difference in light-curing GI after staining and one and two weeks after whitening. @*Conclusion@#The use of whitening toothpaste for two weeks was not different from the use of general toothpaste in the removal of staining or whitening. Since light-curing GI is the most vulnerable to coloration, it is recommended that coloring by food chromogen should be explained in advance, before using light-curing GI for teeth restoration.
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BACKGROUND: The concept of Mild Cognitive Impairment (MCI) refers to a transitional period between normal aging and clinically demented state such as Alzheimer's disease. Detection of individuals with MCI is critical for prognosis of the disease progression and treatment of patients at risk. The current study manipulated linguistic complexity in naming nouns and verbs to examine whether the linguistically different entities contribute to differentiating individuals with MCI from normal elderly adults. Specific aims of the study are 1) to investigate the noun-verb dissociation in naming between the MCI and normal control groups and 2) to examine the differential effects between the groups depending on the linguistic subtypes of nouns (animate vs. inanimate) and verbs (the argument structure). METHODS: Twenty normal elderly individuals and 19 individuals with MCI participated in this study. A confrontation naming task was employed. Nouns were divided into the two subtypes (animate vs. inanimate), and verbs were classified into the three subtypes depending on the number of argument (1-place, 2-place, and 3-place). RESULTS: Results revealed that there were significant differences between the groups, indicating that individuals with MCI showed worse performance on naming in general than the control group. Furthermore, the MCI group presented differentially impaired performance on verbs than nouns compared to the control group. CONCLUSIONS: The results from the current study suggested that performance on a verb confrontation naming task could serve as a sensitive index to differentiate the MCI group from normal aging group.