Laboratory evaluation of the potential masking of color changes produced by silver diamine fluoride in primary molars

Background The importance of Silver diamine fluoride (SDF) as a minimally invasive and nonaerosolizing management during COVID-19 pandemic has highly increased. SDF is a caries-arresting agent that causes staining of tooth structure. Managing this discoloration will increase its acceptance in treating primary teeth. The main aim of this study was to quantify the color change associated with the application of SDF on extracted carious primary molars, the potential masking of this color change by potassium iodide (KI), composite (CMP) and glass ionomer cement (GI) and the effect of aging on this color masking effect. Methods An in-vitro study in which 52 carious primary molars were collected, prepared, and distributed randomly into four groups equally as follows: Group A: SDF 38%; Group B: SDF 38% + KI; Group C: SDF 38% + CMP; Group D: SDF 38% + GI. Color changes were recorded for each sample at baseline, and after application of the tested materials. Moreover, all samples had undergone Suntest aging followed by a third color reading. CIELAB values L*, a*, b*, ΔL, Δa, and Δb were measured, ΔE was calculated, and data were analyzed using multivariate analysis of variance (MANOVA) and post-Hoc Scheffé test (p < 0.05). Results MANOVA revealed the significant influence of the factor ‘material’. SDF caused an obvious color change compared to the color of carious dentin. Regarding ΔL, the color change of groups C and D was not significant directly after application of the tested materials. After aging, it was significant among all groups, including groups C and D. In Δa there was a difference between SDF and groups B and C after application of the tested materials, and aging produced the same results. The color shifts of Δb of all tested groups varied significantly from one another. After aging, there was no difference between group D and either group A or B. Conclusions Treatment with SDF caused obvious discoloration of carious dentin. Directly after SDF application, all tested materials could effectively mask the color change associated with the application of SDF. CMP was the only material whose color masking effect was not completely reversed by aging.

In-vitro efficacy of two spectrophotometer-based shade matching systems for color matching of ceramics after artificial accelerated aging

Objective: The objective of the present invitro study was to verify the efficacy of two spectrophotometer-based shade matching systems for color matching of ceramics after artificial accelerated aging (AAA). Material and Methods: : The ceramics used were porcelain laminated veneers. Seventy standard-shaped discs (thickness x diameter: 0.5 mm x 10 mm) of B1 shades were used. Based upon the type of resin cement used, the specimens were divided into seven groups (10/group). The following light-cured cements were used: RelyX-Veneer (L-RV), Variolink-Veneer (L-VV), and VariolinkEsthetic (L-VE). The dual-cured cements were: RelyX Ultimate (D-RU), RelyX-Unicem (D-RC), and Variolink-Esthetics DC (D-VE). The control group consisted of ceramic only. All specimens were thermocycled in water for 3,500 cycles between 5 o C -55 o C, with dwell times of 30 s in each bath and a transfer time of 10 s between baths. All specimens were thermocycled in water for 3,500 cycles between 5 o C and 55 o C, and color measurement was done using the VITA Easyshade and ColorEye spectrophotometers. Baseline color reading was performed 24-hours after cementation. Differences in color (DE) of EasyShade and ColorEye before and after AAA were determined and compared statistically. Group comparisons were done using the paired t-tests. Level of significance was set at P< 0.05. Results: The mean differences in color (DE) values obtained from EasyShade spectrophotometer for light- and dual-cured cements, were 0.843±0.89 (Lc1), 4.11±0.69 (Lc2) and 0.833±0.47 (Lc3); and 2.22±0.64 (Dc1), 3.37±0.83 (Dc2) and 0.38±0.92 (Dc3), respectively. The mean differences in color (DE) values obtained from ColorEye spectrophotometer for light- and dual-cured cements, were 0.68±0.86 (Lc1), 4.55±0.83 (Lc2) and 2.68±0.26 (Lc3); and 2.06±0.84 (Dc1), 1.8±1.08 (Dc2) and 0.96±0.71 (Dc3), respectively. There was no significant difference in the mean DE values among the groups. Conclusion: The VITA Easyshade and ColorEye shade matching systems are comparable in terms of their efficacy for color matching of cerammics after AAA. Keywords Artificial accelerated aging; Color matching; In vitro; Porcelain veneer; Spectrophotometer.

Misplacement of something inside the refrigerator is not a sign of dementia, but a probable symptom of attention deficit due to depression

The objective of this study is to investigate the clinical significance of a specific behavior of misplacing items in a refrigerator (i.e., placing extremely unusual things such as remote control and/or cellular phone in a refrigerator) as a symptom of cognitive dysfunction. Patients with memory complaints were asked whether they ever experienced misplacing items in a refrigerator, such as placing a remote control, a cellular phone, or other extremely unusual things inside a refrigerator (referred to as the ‘fridge sign’). Among the 2172 individuals with memory complaints, 55 (2.5%) experienced symptoms of the ‘fridge sign’. We investigated the cognitive profiles of ‘fridge sign’-positive patients and performed follow-up evaluations with neuropsychological tests or telephone interviews. The ‘fridge sign’ was mostly found in individuals diagnosed as subjective cognitive decline (n = 33, 60%) or mild cognitive impairment (MCI, n = 20, 36.4%) with depressive mood and was relatively rare in dementia states (n = 2, 3.5%). Moreover, none of the ‘fridge sign’-positive patients showed significant cognitive decline over the follow-up period. We compared the cognitive profiles and the clinical progression of 20 ‘fridge sign’-positive MCI patients and 40 ‘fridge sign’-negative MCI patients. ‘Fridge sign’-positive MCI patients had worse scores on the Stroop test color reading and had higher scores on the geriatric depression scale than ‘fridge sign’-negative MCI patients, which indicates that the ‘fridge sign’ could be indicative of selective attention deficit in patients with depression rather than indicative of cognitive decline related to dementia.

Tooth Discoloration Using Calcium Silicate-Based Cements For Simulated Revascularization in Vitro

The endodontic revascularization may be an alternative treatment for necrotic immature teeth, however, several treatment steps may cause tooth discoloration. This study evaluated the use of three calcium silicate-based cements with different radiopacifying agents on the color alteration (∆E) of extracted premolars after simulation of revascularization. Forty single rooted extracted premolars were shaped with #1-6 gates Glidden drills, rinsed with sodium hypochlorite, and filled with fresh human blood. Three calcium silicate-based cements with different radiopacifying agents (bismuth oxide - CSBi, calcium tungstate - CSW, and zirconium oxide - CSZr) were applied over the blood clot (n=10). The control group received the application of a temporary zinc oxide-based cement (TFZn) (n=10). ∆E was measured with a spectrophotometer, using the L*a*b* color system of the International Commission on Illumination (CIELab), in different times: prior to the preparation of the access cavity (t0); right after treatment (t1); and after one (t2), two (t3), three (t4) and four (t5) months. The tooth site for color evaluation was standardized by silicon matrix, the color reading was performed 3 times per tooth, and the teeth were stored in 37º water between evaluations. ∆E, whiteness (WID index) and yellowness (b*) were evaluated. Data were subjected to one-way ANOVA and repeated measures ANOVA, followed by Tukey’s post hoc test (α=0.05). All groups were similar in ∆E1 (t0-t1). The ∆E was the lowest and constant in the control group. In all evaluation times, CSBi presented the highest ∆E (p<0.01). CSW and CSZr were similar in all evaluated times and presented intermediate ∆E values. WID index from CSBi and CSW presented more distancing from ‘white’ reference. CSBi presented the greatest decrease in yellowness (b* value). The cement containing bismuth oxide presented the highest color alteration values. All tested calcium silicate-based cements presented clinically perceptible discoloration. Calcium tungstate and zirconium oxide may be used as alternative radiopacifiers to decrease tooth discoloration after endodontic tooth revascularization.

Participation Without Power: A Critical Discourse Analysis of Community Meetings in North Denver

Universities help shape cities. Historical forms of racial domination repeat themselves, reproducing spatial subordination. In Denver, residences and businesses owned by families of color will be cleared as Colorado State University (CSU), two museums, and the mayor’s office redevelop the area to build an educational hub. An examination of Citizens Advisory Committee (CAC) meeting transcripts shows that relationships between the higher education institution and the city are changing in racialized ways, as normative institutions overpower low-income communities of color. Reading discursive events from CAC meetings through a theoretical lens reveals the CSU expansion to be an instance of a predominantly white institution working with city leaders to remove people from land so it can be used to better fulfill economic ambitions, exemplifying theories about the spatialization of race and the racialization of space (Lipsitz, 2006, 2007, 2011). This occurrence has implications for higher education researchers and municipal leaders beyond Denver.

Effect of desalted Salicornia europaea L. ethanol extract (PM-EE) on the subjects complaining memory dysfunction without dementia: a 12 week, randomized, double-blind, placebo-controlled clinical trial

Desalted Salicornia europaea L. (SE) inhibits acetylcholine esterase, attenuates oxidative stress and inflammatory cytokines, and activates neurotrophic pathway. We performed 12-week, randomized, double-blind, placebo-controlled study to evaluate the efficacy of PhytoMeal(a desalted SE)-ethanol extract (PM-EE), in improving the cognitive performance in patients with subjective memory impairment. 63 participants complaining memory dysfunction without dementia (Korean Mini-Mental State Examination [K-MMSE] score ≥ 23) were assigned to PM-EE 600 mg/day or placebo. The cognitive domain of the Alzheimer's disease assessment scale-Korean version (ADAS-K) was set as the primary outcome. After 12 weeks, there was no differences in the changes in the primary outcome or the frequency of adverse events between the groups. In the subgroup analysis for the 30 subjects with mild cognitive impairment (MCI, baseline K-MMSE scores ≤ 28), PM-EE significantly improved the color-reading score of the Korean color-word stroop test (8.2 ± 25.0 vs. − 4.7 ± 13.2, P = 0.018). Our findings suggest that PM-EE is safe but might not be effective in this setting of this study. However, PM-EE may improve the frontal executive function in the patients with MCI. Further large-sized studies with longer follow-up period is warranted (trial registration number KCT0003418).

Visual Inspection of Geological Maps: an eye-tracking Study

The paper describes the analysis of a visual inspection of paper geological maps by three groups of participants: geologists (GEOL), geographers (GEO) and geoinformaticians (GIS). The aim of the study was to identify the differences in how different groups of participants visually inspected geological maps.Geological maps show the distribution of different types of rock at the earth’s surface and are a fundamental tool for geologists. Geology as a distinct discipline is relatively young, and its origins date to the eighteenth century. In recent years, this otherwise relatively stable field has begun to incorporate new technology into its tools and methods. No study as yet has been published to assess geological maps using eye-tracking or cognitive cartography.Eye-tracking glasses SMI Eye Tracking Glasses 2 with a recording frequency of 60 Hz were used to record the eye-movements of participants during the experiment. Two maps at a scale of 1 : 25 000 produced by the Czech Geological Survey were used for the eye-tracking experiment. In the first part of the experiment, free viewing was analyzed. In the second part, participants solved six tasks with a map. The tasks were selected based on consultation with employees of the Czech Geological Survey.In the free viewing section, noticeable differences between groups were observed. The free viewing section revealed that the geoinformaticians group concentrated much less on the map itself and spent more time on the surrounding elements. The geographers and geologists mainly focused on the map field. The second part of the experiment comprised six tasks.The first task was the simplest and involved finding the coordinate system used in the map. The task caused no problems in any group, and completion times were balanced. The GIS group demonstrated the greatest experience in reading maps and was also the quickest to solve the task. The second task was to identify the geological units depicted in the map. The correct answer could be obtained either from the legend or by using the scheme of geological units. No statistically significant differences in time between the groups were recorded. In the third task, respondents were required to identify and mark the boundary between two geological units found in the previous task. The group of geologists was quickest to solve this task, and all other respondents found a solution with no great difficulty. The fourth task was to identify the predominant rock and determine its type according to the legend. The results suggest that ten respondents from GEO and GIS groups who concentrated on the lithostratigraphic scheme did not know where to look for the correct answer. In the fifth task, participants were required to mark an area with multiple landslides. The aim in this task was to find the landslide symbol in the legend and then identify the landslide area on the map. The differences between groups were most apparent in this task. The geologists were significantly quicker in finding the symbol in the legend. The other groups needed a much longer time to identify the symbol in the legend. In the final task, respondents were instructed to identify the predominant rock in the area with the highest amplitude of geomagnetic anomalies. To solve this task, using the diagram in the section at the bottom left was necessary. The GEOL group spent the least amount of time completing this task, indicating the respondents’ knowledge. The experiment and subsequent interviews revealed a different color reading strategy. When identifying a rock, the GEOL group compared colors mainly for quick orientation. However, the decisive factor for identification was the index, which was given for the rock in the map and legend.To conclude, the geologists group was quickest in solving the tasks and recorded the least wrong answers. The GIS and GEO groups achieved similar results in the experiment.