In quest for improvement of dyeing properties using agriculture waste: utilization of Oleaster as new bio-mordant for wool yarns.

Agricultural waste is an unwanted material that is not only unmarketable, but also has secondary costs such as environmental pollution. Oleaster, also known as olive Russian fruit, has various uses, but it also produces waste such as seeds and peels. Oleaster fruit and all its parts are tannin rich, which can be utilized as natural mordant. Improvement of fastness and color properties of natural dyed fibers is obtained by using mordant. The employing of this mordant is effective in reducing agricultural waste and the production of dyeing chemical waste. Reseda extract was utilized as natural dye to investigate the color characteristics. The study of the phenolic percentage of different components of the Oleaster fruit, including peel, seed, and flesh, showed that each of these materials can be used as natural mordant. The formation of physical bonds in the presence of all kinds of mordant was investigated using the FTIR method, and the results showed that their performance is similar and they are effective in surface treatment of wool. Investigation of color characteristics of the yarns showed that the color strength increases in the presence of mordant. Studying the fastness of yarns dyed with ISO methods showed that the samples have high washing fastness.

Effect of orthodontic bonding with different surface treatments on color stability and translucency of full cubic stabilized zirconia after coffee thermocycling.

Objective: To assess the color stability and translucency of full cubic stabilized zirconia (FSZ) following orthodontic bonding with different surface treatments and coffee thermocycling (CTC). Methods: This in vitro study was conducted on 120 disc-shaped specimens of FSZ. Thirty specimens were selected as the control group and remained intact. The remaining specimens were randomly divided into three groups based on the type of surface treatment (n = 30): airborne particle abrasion (APA), silica-coating (CoJet), and carbon dioxide (CO2) laser. After metal bracket bonding in the test groups, debonding and polishing were performed. Subsequently, all specimens underwent CTC (10,000 cycles). Color parameters, color difference (ΔE00), and translucency parameter (TP) were measured three times at baseline (t0), after debonding and polishing (t1), and after CTC (t2). Data were statistically analyzed (α = 0.05). Results: Significant difference existed among the groups regarding ΔE00t0t2 (p < 0.001). The APA group showed minimum (ΔE00 = 1.15 ± 0.53) and the control group showed maximum (ΔE00 = 0.19 ± 0.02) color stability, with no significant difference between the laser and CoJet groups (p = 0.511). The four groups were significantly different regarding ΔTPt0t2 (p < 0.001). Maximal increases in TP were noted in the CoJet (1.00 ± 0.18) and APA (1.04 ± 0.38) groups while minimal increase was recorded in the control group (0.1 ± 0.02). Conclusions: Orthodontic treatment makes zirconia restorations susceptible to discoloration and increased translucency. Nonetheless, the recorded ΔE00 and ΔTP did not exceed the acceptability threshold.

Effect of orthodontic bonding with different surface treatments on color stability and translucency of full cubic stabilized zirconia after coffee thermocycling / 대한치과교정학회지

Objective@#To assess the color stability and translucency of full cubic stabilized zirconia (FSZ) following orthodontic bonding with different surface treatments and coffee thermocycling (CTC). @*Methods@#This in vitro study was conducted on 120 disc-shaped specimens of FSZ. Thirty specimens were selected as the control group and remained intact. The remaining specimens were randomly divided into three groups based on the type of surface treatment (n = 30): airborne particle abrasion (APA), silica-coating (CoJet), and carbon dioxide (CO2) laser. After metal bracket bonding in the test groups, debonding and polishing were performed. Subsequently, all specimens underwent CTC (10,000 cycles). Color parameters, color difference (ΔE00), and translucency parameter (TP) were measured three times at baseline (t0), after debonding and polishing (t1), and after CTC (t2). Data were statistically analyzed (α = 0.05). @*Results@#Significant difference existed among the groups regarding ΔE00t0t2 (p < 0.001). The APA group showed minimum (ΔE00 = 1.15 ± 0.53) and the control group showed maximum (ΔE00 = 0.19 ± 0.02) color stability, with no significant difference between the laser and CoJet groups (p = 0.511). The four groups were significantly different regarding ΔTPt0t2 (p < 0.001). Maximal increases in TP were noted in the CoJet (1.00 ± 0.18) and APA (1.04 ± 0.38) groups while minimal increase was recorded in the control group (0.1 ± 0.02). @*Conclusions@#Orthodontic treatment makes zirconia restorations susceptible to discoloration and increased translucency. Nonetheless, the recorded ΔE00 and ΔTP did not exceed the acceptability threshold.

Effect of glazing and polishing on opalescence and fluorescence of dental ceramics.

OBJECTIVE: Tooth enamel has opalescence and fluorescence, which should be mimicked by esthetic dental restorations. The purpose of this study was to compare the effects of glazing and polishing on the opalescence and fluorescence of dental ceramics. MATERIALS AND METHODS: Twenty-four discs were fabricated of feldspathic, IPS e.max, zirconia, and Enamic ceramics with 10 mm diameter and 0.5 and 1 mm thicknesses (n = 12). Of the discs fabricated with 0.5 and 1 mm thicknesses, half of them were glazed and the remaining half were polished (n = 6). Opalescence was calculated as the difference in yellow-blue (CIE ∆b*) and red-green (CIE ∆a*) color axes between the transmitted and reflected colors. The fluorescence of specimens was measured by a novel technique. Data were analyzed using two-way analysis of variance at a 0.05 level of significance. RESULTS: In all groups (except for the Enamic ceramic), the mean opalescence of polished specimens (e.max = 2.704, feldspathic = 1.67, zirconia = 3.143) was higher than that of glazed specimens (e.max = 2.163, feldspathic = 1.016, zirconia = 2.690). The mean opalescence of glazed Enamic specimens (2.140) was higher than that of polished specimens (1.308). The fluorescence of glazed and polished specimens was not significantly different. CONCLUSION: Surface treatment (glazing/polishing) affects the opalescence, but not the fluorescence of dental ceramics evaluated in this study.

LED primary selection algorithms for simulation of CIE standard illuminants.

Although mixture of LEDs is being considered as a simulator of the CIE daylight series, the performance of the simulations is highly dependent on the SPD of the selected LEDs. An algorithm for selection of the best LEDs for simulation of the CIE daylight series is helpful in this regard. To address this problem, using 200 imaginary light primaries and 40 real LEDs, three algorithms based on concepts of equally spacing of wavelength range ("Equal"), Gram Schmidt orthogonalization in LEDs/light primaries spectral subspace ("Gram") and the generalization of Gram Schmidt orthogonalization in the LEDs/light primaries projections onto the illuminants subspace ("Ortho") were proposed and studied. Algorithms, in simulation and reality, were implemented for the CIE standard illuminants of D50, D55, D65 and D75, C and A. The results showed that the performance of the proposed algorithms generally increase with the higher number of selected LEDs/light primaries, while for the LEDs "Gram" and "Ortho" methods showed superior performance, simulations on the imaginary light primaries showed "Ortho" could be considered as the best algorithm.

Discoloration of teeth due to different intracanal medicaments.

OBJECTIVES: The objective of this study was to assess coronal discoloration induced by the following intracanal medicaments: calcium hydroxide (CH), a mixture of CH paste and chlorhexidine gel (CH/CHX), and triple antibiotic paste (3Mix). MATERIALS AND METHODS: Seventy extracted single-canal teeth were selected. Access cavities were prepared and each canal was instrumented with a rotary ProTaper system. The specimens were randomly assigned to CH, CH/CHX, and 3Mix paste experimental groups (n = 20 each) or a control group (n = 10). Each experimental group was randomly divided into 2 subgroups (A and B). In subgroup A, medicaments were only applied to the root canals, while in subgroup B, the root canals were completely filled with medicaments and a cotton pellet dipped in medicament was also placed in the pulp chamber. Spectrophotometric readings were obtained from the mid-buccal surface of the tooth crowns immediately after placing the medicaments (T1) and at 1 week (T2), 1 month (T3), and 3 months (T4) after filling. The ∆E was then calculated. Data were analyzed using 2-way analysis of variance (ANOVA), 3-way ANOVA, and the Scheffé post hoc test. RESULTS: The greatest color change (ΔE) was observed at 3 months (p < 0.0001) and in 3Mix subgroup B (p = 0.0057). No significant color change occurred in the CH (p = 0.7865) or CH/CHX (p = 0.1367) groups over time, but the 3Mix group showed a significant ΔE (p = 0.0164). CONCLUSION: Intracanal medicaments may induce tooth discoloration. Use of 3Mix must be short and it must be carefully applied only to the root canals; the access cavity should be thoroughly cleaned afterwards.

Fluorescence and Opalescence of Two Dental Composite Resins.

OBJECTIVE: Lifelike esthetic appearance of dental restorations is among the main goals in restorative dentistry. This study aimed to assess and compare the opalescence and fluorescence of two dental composite resins. MATERIALS AND METHODS: This in vitro experimental study evaluated the A2 shade of Filtek Z350 XT Enamel, Filtek Z350 XT Dentin, Aelite Aesthetic Enamel, and Aelite All Purpose Body composite resins. Composite discs were fabricated with 10 mm diameter and 0.5 and 1 mm thicknesses (n = 2) using a plexiglass mold and subjected to colorimetry. The color parameters were determined according to the International Commission on Illumination (CIE) L*a*b* system using a spectrophotometer. The fluorescence and opalescence were also measured and reported separately for 0.5 and 1 mm thicknesses of Z350, Aelite Body, and Enamel composite resins. To determine the opalescence, the color of samples in the reflectance mode was measured using a calibration cylinder and in the transmittance mode in presence of 100% ultraviolet (UV) light. To determine the fluorescence, the color of samples against a white background in the reflectance mode in presence or absence of 100% UV light was measured. STATISTICAL ANALYSIS: Data were analyzed using SPSS via three-way analysis of variance and independent t-test. RESULTS: The fluorescence of 0.5 mm thickness of all composites was higher than that of 1 mm thickness (p < 0.05). The fluorescence of Aelite was higher than that of Z350 (p < 0.05). The fluorescence of Aelite Enamel was higher than that of Aelite Body irrespective of their thickness, but the results were opposite for Z350 (p < 0.05). In Aelite composite, opalescence increased by an increase in thickness (p < 0.05). The opalescence of Aelite was significantly higher than that of Z350 (p < 0.05). The opalescence of 0.5 mm thickness of Aelite Enamel was higher than that of Aelite Body, while the opalescence of 1 mm thickness of Z350 Body was higher than that of Z350 Enamel (p < 0.05). CONCLUSION: Thickness, type, and brand of composite resins affected their fluorescence and opalescence.

Discoloration of teeth due to different intracanal medicaments

OBJECTIVES: The objective of this study was to assess coronal discoloration induced by the following intracanal medicaments: calcium hydroxide (CH), a mixture of CH paste and chlorhexidine gel (CH/CHX), and triple antibiotic paste (3Mix). MATERIALS AND METHODS: Seventy extracted single-canal teeth were selected. Access cavities were prepared and each canal was instrumented with a rotary ProTaper system. The specimens were randomly assigned to CH, CH/CHX, and 3Mix paste experimental groups (n = 20 each) or a control group (n = 10). Each experimental group was randomly divided into 2 subgroups (A and B). In subgroup A, medicaments were only applied to the root canals, while in subgroup B, the root canals were completely filled with medicaments and a cotton pellet dipped in medicament was also placed in the pulp chamber. Spectrophotometric readings were obtained from the mid-buccal surface of the tooth crowns immediately after placing the medicaments (T1) and at 1 week (T2), 1 month (T3), and 3 months (T4) after filling. The ∆E was then calculated. Data were analyzed using 2-way analysis of variance (ANOVA), 3-way ANOVA, and the Scheffé post hoc test. RESULTS: The greatest color change (ΔE) was observed at 3 months (p < 0.0001) and in 3Mix subgroup B (p = 0.0057). No significant color change occurred in the CH (p = 0.7865) or CH/CHX (p = 0.1367) groups over time, but the 3Mix group showed a significant ΔE (p = 0.0164). CONCLUSION: Intracanal medicaments may induce tooth discoloration. Use of 3Mix must be short and it must be carefully applied only to the root canals; the access cavity should be thoroughly cleaned afterwards.

Image-based spectral transmission estimation using "sensitivity comparison".

Although digital cameras have been used for spectral reflectance estimation, transmission measurement has rarely been considered in studies. This study presents a method named sensitivity comparison (SC) for spectral transmission estimation. The method needs neither a priori knowledge from the samples nor statistical information of a given reflectance dataset. As with spectrophotometers, the SC method needs one shot for calibration and another shot for measurement. The method exploits the sensitivity of the camera in the absence and presence of transparent colored objects for transmission estimation. 138 Kodak Wratten Gelatin filter transmissions were used for controlling the proposed method. Using modeling of the imaging system in different levels of noise, the performance of the proposed method was compared with a training-based Matrix R method. For checking the performance of the SC method in practice, 33 manmade colored transparent films were used in a conventional three-channel camera. The method generated promising results using different error metrics.

Retinopathy of Prematurity-assist: Novel Software for Detecting Plus Disease

PURPOSE: To design software with a novel algorithm, which analyzes the tortuosity and vascular dilatation in fundal images of retinopathy of prematurity (ROP) patients with an acceptable accuracy for detecting plus disease. METHODS: Eighty-seven well-focused fundal images taken with RetCam were classified to three groups of plus, non-plus, and pre-plus by agreement between three ROP experts. Automated algorithms in this study were designed based on two methods: the curvature measure and distance transform for assessment of tortuosity and vascular dilatation, respectively as two major parameters of plus disease detection. RESULTS: Thirty-eight plus, 12 pre-plus, and 37 non-plus images, which were classified by three experts, were tested by an automated algorithm and software evaluated the correct grouping of images in comparison to expert voting with three different classifiers, k-nearest neighbor, support vector machine and multilayer perceptron network. The plus, pre-plus, and non-plus images were analyzed with 72.3%, 83.7%, and 84.4% accuracy, respectively. CONCLUSIONS: The new automated algorithm used in this pilot scheme for diagnosis and screening of patients with plus ROP has acceptable accuracy. With more improvements, it may become particularly useful, especially in centers without a skilled person in the ROP field.

Metric for evaluation of filter efficiency in spectral cameras.

Although metric functions that show the performance of a colorimetric imaging device have been investigated, a metric for performance analysis of a set of filters in wideband filter-based spectral cameras has rarely been studied. Based on a generalization of Vora's Measure of Goodness (MOG) and the spanning theorem, a single function metric that estimates the effectiveness of a filter set is introduced. The improved metric, named MMOG, varies between one, for a perfect, and zero, for the worst possible set of filters. Results showed that MMOG exhibits a trend that is more similar to the mean square of spectral reflectance reconstruction errors than does Vora's MOG index, and it is robust to noise in the imaging system. MMOG as a single metric could be exploited for further analysis of manufacturing errors.