scholarly journals Shade Matching Performance of Dental Students with Three Various Lighting Conditions

2013 ◽  
Vol 14 (1) ◽  
pp. 100-103 ◽  
Author(s):  
Hamid Jafarzadeh ◽  
Mohammadreza Nakhaei ◽  
Jalil Ghanbarzadeh ◽  
Shirin Keyvanloo ◽  
Samin Alavi

ABSTRACT Aim To evaluate the ability of dental students to match shades under three various light conditions. Materials and methods Sixty senior dental students participated in this study. All students were tested for color deficiency using Ishahara's tests. Nine classical vita shade tabs were randomly selected and their identification codes were concealed. The students were asked to match these 9 selected items by using a complete vita shade guide under three various light conditions (natural light, clinical light, and correcting light source). The chosen shade tabs were recorded and the correct matches were counted. Scores were calculated by adding the number of correct matches. Results The mean values of correct match scores with natural light, clinical light and correcting light source were 4.82, 4.75 and 6.82, respectively. There was no significant difference in correct matches scores between men and women, nor among various vita A, B, C and D shades. Conclusion The students showed a better performance in shade matching under the correcting light source than natural light and clinical light. Gender had no effect on shade matching selection and there was no difference in shade matching ability among vita A, B, C, D shades. Clinical significance Shade matching performance is significantly improved with correcting light source. How to cite this article Nakhaei M, Ghanbarzadeh J, Keyvanloo S, Alavi S, Jafarzadeh H. Shade Matching Performance of Dental Students with Three Various Lighting Conditions. J Contemp Dent Pract 2013;14(1):100-103.

2016 ◽  
Vol 17 (1) ◽  
pp. 22-26 ◽  
Author(s):  
Mohammadreza Nakhaei ◽  
Jalil Ghanbarzadeh ◽  
Samin Alavi ◽  
Sahar Amirinejad ◽  
Hamidreza Rajatihaghi

ABSTRACT Aim There is limited and inconsistent information on some factors affecting visual shade selection. The aim of this study was to evaluate the influence of shade guide type and professional experience on shade-matching results. Materials and methods Thirty Dental students (DS), 30 General dentists (GDs) and 30 Dental specialists (S) participated in this study. The participants were asked to match six target tabs using two dental shade guides: Vitapan Classical (VC) and Vitapan 3D-Master (3D). An intraoral spectrophotometer was used for color measurement of target tabs and selected tabs. The color difference (Conflict of interest: NoneE) values between the target tab and selected tab were calculated. Data were analyzed using analysis of variance (ANOVA) and paired t-test (α = 0.05). Results of the first five best matches for each target tab were expressed as ΔE1 to ΔE5. Differences in the mean values of ΔE1 to ΔE5 between VC and 3D were compared using descriptive statistics. Results There were no significant differences among the three participating groups in ΔE values when the 3D was used (p = 0.389). However, significant differences were found with VC (p < 0.001). The ΔE values achieved from the 3D were significantly lower than those from VC for DS and S (p = 0.001 and p < 0.001, respectively). For each of the first five best matches, the mean ΔE values from the 3D were smaller than the corresponding values of VC. Conclusion The type of dental shade guide affected the shadematching results. The level of experience was not found to be an influential factor in shade matching when 3D-Master shade guide was used. Clinical significance Compared with Vitapan Classical shade guide, use of the Vitapan 3D-Master shade guide improves shade-matching results. How to cite this article Nakhaei M, Ghanbarzadeh J, Amirinejad S, Alavi S, Rajatihaghi H. The Influence of Dental Shade Guides and Experience on the Accuracy of Shade Matching. J Contemp Dent Pract 2016;17(1):22-26.


Author(s):  
Vitor Sarri ◽  
Beatriz Ferrari ◽  
Larissa Magalhães ◽  
Paula Rodrigues ◽  
Almir Rezende ◽  
...  

Objective The aim of this study is to evaluate whether exposure to different environmental lighting conditions affects the reproductive parameters of pregnant mice and the development of their offspring. Methods Fifteen pregnant albino mice were divided into three groups: light/dark, light, and dark. The animals were euthanized on day 18 of pregnancy following the Brazilian Good Practice Guide for Euthanasia of Animals. Maternal and fetal specimens were measured and collected for histological evaluation. Analysis of variance (ANOVA) test was used for comparison of the groups considering p ≤ 0.05 to be statistically significant. Results There was no significant difference in the maternal variables between the three groups. Regarding fetal variables, significant differences were observed in the anthropometric measures between the groups exposed to different environmental lighting conditions, with the highest mean values in the light group. The histological evaluation showed the same structural pattern of the placenta in all groups, which was within the normal range. However, evaluation of the uterus revealed a discrete to moderate number of endometrial glands in the light/dark and light groups, which were poorly developed in most animals. In the fetuses, pulmonary analysis revealed morphological features consistent with the transition from the canalicular to the saccular phase in all groups. Conclusion Exposure to different environmental lighting conditions had no influence on the reproductive parameters of female mice, while the offspring of mothers exposed to light for 24 hours exhibited better morphometric features.


Uniciencia ◽  
2017 ◽  
Vol 31 (2) ◽  
pp. 121
Author(s):  
José Antonio García-García ◽  
José Bernal Azofeifa-Bolaños

In order to understand the performance of Solanum tuberosum L. “Floresta” in producing microtubers, the effect of four concentrations of boric acid (6.2 mg l-1, 7.75 mg l-1, 9.3 mg l-1, and 10.85 mg l-1) under two conditions—1) 8 hour dark and 2) 16 hour light photoperiod and 8 hour dark—was evaluated under in vitro culture conditions. Full-strength Murashige and Skoog medium was used as a control. The data analysis for the number and biomass of microtubers were significant for the condition (p ≤ 0.05). Concerning the concentration of boric acid and the interaction between factors, a significant difference was obtained for biomass (p ≤ 0.05). In dark conditions, a greater number of microtubers was obtained, although the biomass was lower compared to the light conditions where the biomass was higher, and the number of microtubers was lower. A concentration of 9.3 mg l-1 of boric acid in both types of conditions was the best treatment to produce a greater number and more biomass of microtubers. The differences identified in this work with regards to the number and biomass of microtubers were probably the combined result of genotype and specific culture conditions. Even considering this, the use of lighting conditions is proposed to induce larger and greener microtubers.


10.1563/828.1 ◽  
2006 ◽  
Vol 32 (5) ◽  
pp. 256-258 ◽  
Author(s):  
Sheldon Winkler ◽  
Kenneth G. Boberick ◽  
Kasia S. Weitz ◽  
Isaac Datikashvili ◽  
Robert Wood

Abstract Dental students achieved a high identification rate for darker shades (P14 and P24) on the Portrait IPN shade guide, which represent the highest chroma and lowest value in the grayish and reddish yellow hue groups. A high identification rate was also obtained for P32, representing the lowest chroma and highest value in the reddish gray hue group. The data suggest that dental students had the most difficulty determining the correct hue group for unmarked shade tabs. Incorrect responses tended to remain in the same value and chroma range but were selected in a different hue group.


2020 ◽  
Vol 14 (1) ◽  
pp. 539-543
Author(s):  
Abdulhaq Suliman ◽  
Tholfikar Al-Abdali ◽  
Mohammed Taslimi ◽  
Ahmad Abdo

Objective: Shade selection is a crucial step in achieving aesthetically-pleasing restorations, and it is affected by the dentist’s ability to match the shade of the patient’s teeth. Color Deficiency Disease (CVD) has been thought to be a potential factor affecting color perception. The study aims to find the prevalence of CVD between dentists and dental students and to evaluate its effect on shade matching ability. Methods: A sample of 319 dentists and dental students in the College of Dentistry at Ajman University, Ajman, UAE was examined with the Ishihara test to find the prevalence of CVD. Then participants with CVD were tested for shade matching ability, and were compared to participants with normal color vision with the same gender and qualification level. They were asked to match 10 random composite samples with different shades to a custom shade guide made from the same composite material. A score was calculated, representing the number of correct answers they achieved. Results: The results showed that 8 out of 143 males (5.6%) had CVD, and 0 out of 176 females had CVD. There was no significant difference in the score of shade matching test between participants with CVD and participants with normal color vision (p=0.075). Conclusion: Males showed a higher prevalence of color vision deficiency than females. CVD had no significant effect on shade matching ability.


1966 ◽  
Vol 53 (2) ◽  
pp. 177-188 ◽  
Author(s):  
P. Lund-Johansen ◽  
T. Thorsen ◽  
K. F. Støa

ABSTRACT A comparison has been made between (A), a relatively simple method for the measurement of aldosterone secretion rate, based on paper chromatography and direct densitometry of the aldosterone spot and (B) a more elaborate isotope derivative method. The mean secretion rate in 9 normal subjects was 112 ± 26 μg per 24 hours (method A) and 135 ± 35 μg per 24 hours (method B). The »secretion rate« in one adrenalectomized subject after the intravenous injection of 250 μg of aldosterone was 230 μg per 24 hours (method A) and 294 μg per 24 hours (method B). There was no significant difference in the mean values, and correlation between the two methods was good (r = 0.80). It is concluded that the densitometric method is suitable for clinical purposes as well as research, being more rapid and less expensive than the isotope derivative method. Method A also measures the urinary excretion of the aldosterone 3-oxo-conjugate, which is of interest in many pathological conditions. The densitometric method is obviously the less sensitive and a prerequisite for its use is an aldosterone secretion of 20—30 μg per 24 hours. Lower values are, however, rare in adults.


Author(s):  
Marcela Moreira Salles ◽  
Viviane de Cássia Oliveira ◽  
Ana Paula Macedo ◽  
Claudia Helena Silva-Lovato ◽  
Helena de Freitas Oliveira Paranhos

Implant-supported prostheses hygiene and peri-implant tissues health are considered to be predictive factors for successful prosthetic rehabilitation. Therefore, the purpose of this study was to evaluate the effectiveness of brushing associated with oral irrigation measured as biofilm-removing capacity, maintenance of healthy oral tissues, and patient satisfaction. A randomized, crossover clinical trial was conducted with 38 patients who wore conventional maxillary complete dentures and mandibular overdentures retained by the O-ring system. The patients were instructed to use the following hygiene methods for 14 days: mechanical brushing [MB (brush and dentifrice - Control)]; and MB with oral irrigation [WP (Waterpik - Experimental)]. Biofilm-removing capacity and maintenance of healthy oral tissues were evaluated by the Modified Plaque Index (PI), Gingival Index (GI), Probing Depth (PD), and Bleeding on Probing Index (BP) recorded at baseline and after each method. In parallel, patients answered a specific questionnaire using a Visual Analogue Scale after each hygiene method. Data were analyzed by Friedman and Wilcoxon tests (α=0.05). The results showed significantly lower PI, GI, PD, and BP indices after application of the hygiene methods (P&lt;0.001) than those observed at baseline. However, no significant difference was found between MB and WP. The satisfaction questionnaire responses to both methods showed high mean values for all questions, with no statistically significant difference found between the answers given after the use of MB and WP (P&gt;0.05). The findings suggest that WP was effective in reducing PI, GI, PD, and BP indices and provided a high level of patient satisfaction.


2017 ◽  
Vol 13 (1) ◽  
Author(s):  
Izabel Aparecida Soares ◽  
Mauro Sérgio Téo ◽  
Carlise DEBASTIANI ◽  
Suzymeire BARONI ◽  
Vanessa Silva RETUCI

O trabalho teve por objetivo verificar diferenças entre rendimento do concentrado proteico e proteína bruta da folha da mandioca (Manihot esculenta Crantz), obtidos a partir de três variedades comerciais: branca, cascuda e vermelha. As manivas foram plantadas seguindo o delineamento experimental inteiramente casualizado com três repetições. Nas comparações entre as variedades, considerou coletas escalonadas pós-plantio, realizadas aos 12, 14 e 16 meses. O concentrado proteico foi obtido a partir da farinha das folhas inteiras e submetido ao método de termo - coagulação ácido e a proteína bruta pelo método padrão AOAC. Os dados foram submetidos a análise de variância e comparados pelo teste de Tukey - 5% de probabilidade. Os resultados não indicaram diferença significativa entre as médias obtidas para rendimento de concentrado proteico. Para a variável porcentagem de proteína bruta a variedade Branca foi a que apresentou maior valor, com média de 46,25%, seguida pela Cascuda e Vermelha, 44,52% e 37,30%, sucessivamente. Conclui-se que outros estudos devem avaliar condições que possam influenciar no teor de proteína foliar, como clima e solo, e, avaliar os níveis de ácido cianídrico de cada variedade, indicando qual das três é a melhor para a extração do concentrado proteico das folhas. Palavras chaves: Manihot esculenta Crantz, variedades comerciais, concentrado proteico, proteína bruta. ABSTRACT: The study aimed to assess the differences between income protein concentrate, crude protein of cassava leaf (Manihot esculenta Crantz), obtained from three commercial varieties: white, red and cascuda. The cuttings were planted following the completely randomized design with three replications. Comparisons between the varieties considered after planting staggered collections, held on 12, 14 and 16 months. The protein concentrate was obtained from flour of whole sheets and subjected to the term method - acid coagulation and crude protein by AOAC standard method. The data were submitted to ANOVA and Tukey test - 5% probability. The results indicated no significant difference between the mean values obtained for protein concentrate income. For the variable percentage of crude protein White variety showed the highest, with an average of 46.25%, followed by cascuda and Red, 44.52% and 37.30%, successively. We conclude that further studies should evaluate conditions that may affect the leaf protein content, such as climate and soil, and evaluate the hydrocyanic acid levels of each variety, indicating which of the three is the best for the extraction of protein concentrate from leaves Key words: Manihot esculenta Crantz, commercial varieties, protein concentrate, crude protein.


2019 ◽  
pp. 84-92
Author(s):  
Anh Chi Phan ◽  
Xuan Anh Ngoc Ho

Background: The condylar position discrepancy between centric relation and maximal intercuspation has been still a controversial issue. Aims: To compare the condylar position between centric relation and maximal intercuspation using cone-beam tomography in patients without temporomandibular joints disorder. Materials and methods: To assess the condylar position in centric relation and maximal intercuspation using cone-beam tomography on 40 fifth-year and sixth-year dental students of Hue University of Medicine and Pharmacy without temporomandibular joints disorder. The condylar positions are assessed following Sener classification (2009) and are compared between centric relation and maximal intercuspation using pairedsamples t-test and Mann-Whitney U-test. Results: Among 480 condye-to-fossa measurement pairs, there are 91.2% pairs having difference between two reference position but there is no significant difference. The condylar position at the superior of mandibular fossa has the greatest percentage in both centric relation and maximal intercuspation (43.8% in centric relation and 51.2% in maximal intercuspation). This greatest percentage is followed by the condylar position at posterior of mandibular fossa (32.5% in centric relation and 36.3% in maximal intercuspation). Lastly, the condylar position at the anterior of mandibular fossa has the fewest percentage (23.7% in centric relation and 12.5% in maximal intercuspation). Conclusion: There is no significant difference of condylar position between centric relation and maximal intercuspation in patients without temporomandibular joints disorder. Key words: Condylar position, centric relation, maximal intercuspation, cone-beam tomography


2021 ◽  
Vol 80 (Suppl 1) ◽  
pp. 1078.1-1079
Author(s):  
I. Yoshii

Background:Patient’s global assessment (PGA) is one important component of Boolean composite criteria for remission in treat with rheumatoid arthritis (RA). However, PGA no more than 10mm is sometimes obstacle to attain clinical remission. In recent few years, one opinion that PGA no more than 20mm may be comparable as no more than 10mm.Objectives:The aim of this study is to analyze how difference of these PGA level affect disease activity and daily activities in living, and evaluate which is optimal for the remission with Boolean remission criteria from real world setting.Methods:RA patients who were followed up for more than three years in the institute were picked up in the study. Each patient was monitored with tenderness joint count (TJC), swollen joint count (SJC), PGA, evaluator’s global assessment (EGA), serum C-reactive protein level (CRP), calculated disease activity score with simplified disease activity index(SDAI), Health Assessment Questionnaire Disability Index (HAQ-DI), and pain score using visual analog scale (PS-VAS) every consulted time from the first encounter (Baseline). Patients were classified according to achievement of Boolean remission criteria. Group 1: a patient group who attained Boolean remission wih TJC≦1, SJC≦1, CRP≦1mg/dl, and PGA≦1 (G-1), Group 2: a patient group who could not attained the Boolean remission used in the G-1 evaluation, but could attained another Boolean remission with TJC≦1, SJC≦1, CRP≦1mg/dl, and PGA≦2 (G-2), and Group 3: a patient group who could not attain Boolean remission for neither criterion.Mean values of measured parameters at Baseline and after the Baseline were compared statistically with Student T-test. Mean values of the same parameters in the G-1 and G-2 at the time of attain Boolean remission for each criteria, mean values of each of these parameters thereafter, and changes of these parameters were compared statistically with Student T-test.Results:A total of 438 patients 385 in the G-1 group, 16 in the G-2 group, and 37 in the G-3 group, were recruited. In parameters at Baseline, level of TJC, SJC, PGA, EGA, SDAI, and HAQ-DI in the G-1 was significantly lower than in the G-3, whereas no significant differences in any parameters demonstrated between in the G-2 and G-3. Level of HAQ-DI, and PS-VAS after Baseline in the G-1 was lower than in the G-3, whereas no significant difference of these parameters after Baseline demonstrated between in the G-2 and G-3. TJC, SJC, PGA, and EGA demonstrated significant less level in the G-1 than in the other two groups. The mean SDAI score at the time of first achievement of Boolean remission in the G-1 and G-2 were 1.08 and 2.57, respectively. The mean value of SDAI score after remission in the G-1 and G-2 were 3.35 and 6.44, respectively. These values and PS-VAS including change of the SDAI score demonstrated significant difference between the two groups (p<0.01), whereas HAQ-DI in the two groups demonstrated no significant difference.Conclusion:These results suggested that setting PGA as no more than 10mm should be reasonable for the evaluation of clinical remission with the Boolean criteria.Disclosure of Interests:None declared


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