Maintain Color Stability Research Articles

Effects of different remineralizing agents on color stability and surface characteristics of the teeth following vital bleaching

The aim of the study was to investigate the effects of various remineralizing agents on the color stability and surface characteristics of the teeth after vital bleaching. The extracted 96 human incisors were used for the study. Initially, the samples were randomly divided into two groups and exposed to in-office and at-home bleaching agents. Then, the groups were divided into six subgroups (n = 8), including the control group did not undergo remineralization after bleaching, according to five remineralizing agents (Gelato APF Gel, Remin Pro, Tooth Mousse, MI Paste Plus, Curodont Protect). Surface roughness was assessed at baseline, after bleaching and remineralization procedures. Color measurements of the samples were obtained at baseline, after bleaching and then after immersion in the staining solution following remineralization process. Scanning electron microscopy and atomic force microscopy (AFM) analyzes were carried out in order to examine the morphological changes on the surface of the enamel. The independent t-test, paired-samples t-test, and one-way ANOVA was used to compare the data and post-hoc LSD test to compare the difference among the study groups (α = .05). Surface roughness increased following in-office and at-home bleaching in all groups, and reduced after application of remineralizing agents in all groups. Significant differences were found among the groups with respect to changes in surface roughness and color values following treatment with remineralizing agents (p <.05). AFM analyses revealed increased surface roughness after bleaching and a reduction of rough surfaces following treatment with remineralizing agents. Remineralizing agents can be used to reduce postbleaching increase in surface roughness and to maintain color stability after bleaching.

Yacon-based Beverage as Non-dairy Vehicle for Bifidobacterium animalis ssp. lactis: Stability and In vitro Probiotic Viability

Probiotics are health-promoting microorganisms commonly applied to functional foods. Dairy products are the most common source of probiotics, which difficult probiotics’ consumption by lactose intolerants. In this work, a yacon-based (Smallanthus sonchifolius) beverage was evaluated as a non-dairy vehicle for probiotics (Bifidobacterium animalis ssp. lactis, BB-12®), concerning stability and probiotics viability, during 28 days. x The yacon-based beverage was properly obtained. To determine the better treatment to stabilize it during storage, combined treatments were optimized via experimental design, and the color stability evaluated the initial changes. The beverage was incubated with the probiotic strain Bifidobacterium animalis ssp. lactis and the fermentation were carried out at 45 °C and 35 °C for 10 h in anaerobic jars. The storage viability was evaluated for 28 days, and the viable cell counting was carried out every seven days. A combination of the immersion of yacon slices into ascorbic acid 0.5% (w/v), blanching (3 min), and the addition of 0.4% (w/v) of ascorbic acid as an antioxidant was the most promising treatment to maintain color stability. Moreover, the fermentation applying 35 °C maintained the beverage with probiotic status for 14 days. In this work, a probiotic beverage was proposed, with potential health benefits, based on an underused root with great productivity, which will result in a potential low-cost probiotic product compared to dairy-based probiotic beverages.

Color Stability of Glass Ionomer Cement (GIC) Modified with Silica from Beach Sand after Immersion in Arabica Gayo Coffee

The discoloration is a condition that can affect the color stability of a material. The discoloration of glass ionomer cement (GIC) can occur due to extrinsic and intrinsic factors. GIC has poor mechanical properties, which are brittle, which shows high microporosity in GIC. Microporosity of GIC can affect the ability of materials in maintaining color stability. Therefore, it is necessary to add material alternatives to improve the mechanical properties in order to maintain color stability in GIC, such as silica. This study aims to determine the color change in GIC which is added with 5% silica after immersion in gayo arabica packaging coffee. Cylindrical specimens with a diameter of 5 mm and 2 mm thick. Specimens amounted to 16 pieces consisting of two treatment groups, the first group using conventional GIC and the second group using GIC with the addition of silica. Both groups were immersed in arabica gayo coffee for 4 days. Color changes were observed with a stereomicroscope and then the value of CIELab was used using Adobe Photoshop, which measured its average color change parameter (ΔE). The average value of discoloration of conventional GIC ΔE = 5.77 and GIC with the silica addition ΔE = 7.94. The results of the unpaired t-test show a value (p&gt; 0.05) which means that there is a significant color change. It can be concluded that the two groups had discoloration after immersion in Arabica gayo coffee, and the color change value in conventional GIC with the addition of silica was higher than conventional GIC.

The Effects of Natural Antioxidants on Protein Oxidation, Lipid Oxidation, Color, and Sensory Attributes of Beef Patties during Cold Storage at 4℃.

This study aimed to investigate the use of golden thread extract (GTE), clove extract (CE), and commercially available nitrite for retarding lipid and protein oxidation and for maintaining color stability and sensory attributes in beef patties stored at 4℃. GTE, CE, and nitrite treatment samples were found to be efficient in retarding lipid oxidation as all three treatments resulted in low thiobarbituric acid reactive substance (TBARS) content (p<0.05). By using GTE, CE, and nitrite into beef patties, protein oxidation was not developed. Incorporation of GTE and CE into beef patties maintained color stability by protecting against the decrease of L*, a*, b*, chroma, and hue angle values and exhibited significant influence on sensory characteristics, including color and odor of beef patties (p<0.05). Compared to commercially available nitrite, GTE and CE were more effective as antioxidants for inhibiting lipid oxidation, and preserving color stability of fresh beef patties. The study indicated that GTE and CE could be utilized efficiently to extend the shelf life of beef patties.

Mild high hydrostatic pressure pretreatments applied before soaking process to modulate wholegrain brown rice germination: An examination on embryo growth and physicochemical properties

This investigation aimed to examine the effects of a novel processing pattern, combining high hydrostatic pressure (HHP) with germination, on the embryo growth and physicochemical characteristics of wholegrain brown rice (WBR). WBR grains were firstly subjected to mild HHP stress (30–90 MPa/5 min) and then incubated at 37 °C for 52 h for obtaining germinated samples (GBR). The results showed that HHP shock resulted in a delayed embryo growth of WBR grains, maintaining acceptable sprouting rates ranging from 65% to 76% when germination was finished. The contents of gama-aminobutyric acid in GBR were greatly increased responding to HHP stress, showing pressure intensities dependent. Total digestible and resistant starch contents in samples stressed at 60/90 MPa were decreased, mainly associated with high pressure-induced amorphization as revealed by SEM imaging and FTIR, which promoted starch hydrolysis during germination. Besides, the levels of zinc and iron were influenced by HHP pretreatments due to the high pressure-mediated degradation behavior for phytic acids. The storability of HHP-stressed GBR grains was significantly enhanced through reducing free fatty acids formation and maintaining color stability during a storage testing. These results obtained from the current work demonstrated that mild HHP stress pretreatment prior to germination process could be used as a promising strategy to modulate certain physicochemical characteristics of WBR products.

The Effects of Storage Conditions on Lycopene Content and Color of Tomato Hot Pot Sauce.

Tomato hot pot sauce (THPS) at different storage temperatures (0, 25, and 37°C) and with two kinds of packaging for 120 days was investigated in this study. High performance liquid chromatography was employed for detecting lycopene and 5-hydroxymethylfurfural (HMF). The changes of lycopene and HMF during storage were regressed with kinetic equation of both zero-order and first-order models, and the latter fitted better. The kinetic equation constant (k value) of lycopene or HMF at 37°C was higher than that at 25°C. The k value of lycopene of PET/PE (P1) packaged THPS was 1.60 times of that of PET/Al/EAA/PE (P2) packaged at 37°C, while it was 2.12 times at 25°C. The k value of HMF of P1 packaged THPS was 1.69 times of that of P2 packaged at 37°C, while it was 1.01 times at 25°C. Significant correlations between color index of L⁎, a⁎, and a⁎/b⁎ and lycopene or HMF were found at storage temperature. Browning color was attributed to both Maillard reaction and degradation of lycopene. In conclusion, lower storage temperature and stronger oxygen barrier property of package could maintain color stability and extend shelf life.

Effect of Staining and Bleaching on Color stability and Surface Roughness of Three Resin Composites: An in vitro study.

Aim:This study evaluated the effect of staining and subsequent bleaching on the color stability and surface roughness of three resin composites.Materials and Methods:One hundred and eight customized plastic disks from a plastic mold with an outer diameter of 10 mm and thickness of 1.02 mm were fabricated. Samples were divided into three groups of 36 specimens each – Group I (Estelite® α – Supranano), Group II (Filtek™ Z250 XT – Nanohybrid), and Group III (Filtek™ P90–Silorane). Subsequently, baseline surface color and roughness values were tabulated using spectrophotometer and profilometer, respectively. The specimens were then subjected to staining with coffee and turmeric for a period of 3 h/day for 40 days and following this, bleaching of the samples was done using a bleaching agent carbamide peroxide gel 15% for 8 h/day for 14 consecutive days.Results:Estelite® α performed better by maintaining color stability with minimal roughness compared to Filtek™ P90 and Filtek™Z250 XT. Turmeric had a greater potential to stain composites compared to coffee in all the groups.

Pomegranate Rind Extract Limits Ground Beef Color Discoloration and Lipid Oxidation

ObjectivesMeat color has a substantial influential in purchasing decisions as consumers associate color with freshness. Discoloration of beef at retail has resulted in a loss of about $1 billion annually. Many additives, including antioxidants, have been utilized in products such as ground beef to increase their shelf life. Therefore, the overall goal of this study was to evaluate the effects of pomegranate rind extract on ground beef color stability and lipid oxidation. Materials and MethodsThe pomegranate rind extract was prepared by mixing dried ground rind powder in boiling water. The mixture was centrifuged to extract the pomegranate rind extract. Course ground beef (80% lean) was mixed with 0, 1, and 1.5% of pomegranate rind extract. The pomegranate rind extract was included into the sample, reground and then formed into a 100 g patty, utilizing the adjust-a-burger patty press. Patties from each treatment were then assigned to 4 different packaging types: PVC, Hi-Ox, CO, and vacuum. Patties packaged in CO and vacuum bags were stored in dark storage 5 d prior to display. The vacuum patties were removed form the bags, packaged in PVC and allowed 1 h to bloom prior to evaluation. Patties packaged in PVC, CO and vacuum were on display for 3 d while patties packaged in Hi-Ox were left on display for 5 d. Patties were evaluated each day by trained color panelists (6 members). Patties were evaluated for display color and surface discoloration. Thiobarbituric acid values were used to indicate lipid oxidation. Lipid oxidation was measured on the control patties on d 0 and then evaluated on all treatments at the end of their assigned display time. The experiments were replicated 6 times (n = 6). The data were analyzed using the Mixed Procedure of SAS, and considered significant at a level of P < 0.05. ResultsDisplay color was brighter cherry red for samples with pomegranate solution compared to the control samples (P < 0.05). Similarly, surface discoloration decreased for patties with the addition of pomegranate solution compared to the controls (P < 0.05). Patties packaged in Hi-Ox maintained color stability longer (P < 0.05) than patties packaged in PVC, CO, and vacuum. There were decreases (P < 0.05) in the lipid oxidation levels of the patties enhanced with 1.0 and 1.5% pomegranate solution compared to the control patties, for all packaging types. Samples enhanced with 1.5% pomegranate solution in vacuum and PVC packaging had 50% less lipid oxidation after display than the control. Similarly, samples with 1.5% pomegranate solution packaged in CO had 65% and Hi-Ox had 75% less lipid oxidation compared to the controls. ConclusionThe use of pomegranate as an antioxidant in ground beef patties had major positive impacts on both color stability and overall freshness (lipid oxidation). The addition of pomegranate will increase the shelf life of ground beef and ultimately decrease the economical loss that results from discoloration of meat.

Methylation of Brazilein on Secang (Caesalpinia sappan Linn) Wood Extract for Maintain Color Stability to the Changes of pH

The stability of natural dyes to the changes of pH is really necessary when the natural dyes are applied either on fabric or food. This research aimed to increase the stability of brazilein, a compound contained within the secang wood extract, to the changes of pH. The methylation process was done by reacting Dimethyl Carbonate (DMC) with the brazilein on the secang wood extract. DMC acts as a substance that substitute hydroxyl group on brazilein. The methylation reaction of brazilein on secang wood extract was operated on a three-necked round-bottomed flask fitted with mercury-sealed stirrer and reflux condenser under 80°C temperature and 250 rpm stirring speed. There were two variables observed in this research; the DMC amount ratio to the amount of secang wood extract and the time of the methylation process. The research showed that at the 1:10 the DMC amount ratio to the amount of wood extract and 8 hours of the methylation process give the better stability of color of the secang wood extract than the variation of the other variables.

EFFECT OF HEATED COMPOSITE CEMENT AND WEAR WITH DIFFERENT OPPOSING SURFACES ON COLOR OF CAD/CAM CERAMIC OCCLUSAL VENEERS

Statement of problem: improvement and maintain color stability of ceramic restorations is necessary factor for long success of esthetic fixed Prosthodontic restorations. Posterior occlusal ceramic and hybrid ceramic veneers are widely used as a clinical restorative treatment to improve appearance and restore the lost enamel. The abrasiveness limitation of different ceramics materials and its effect on color stability of both enamel and different opposing occlusal restorative materials are very important when selecting as an esthetic restorative material. In addition, recently, composite resin has been used as luting cement for indirect aesthetic restorations. The flow of the pre-heating composite as luting agent improves the adaptation and facilitate the placement of the restoration. Therefore, the effect of heat on color stability of composite as luting agent and its reflection on the color of occlusal ceramic veneers restorations are neededObjectives: this study was to investigate the effect of heating of flowable composite as luting agent and the wear of occlusal veneer ceramic restoration with different opposing(enamel, e. max and v. enamic) on the color of e. max and vita enamic CAD/CAM posterior occlusal veneers ceramic restorations.Materials and Methods: 20 extracted human upper premolars were prepared for occlusal veneers were scanned and CAD-CAM restorations were milled using e max and vita enamic CAD/CAM blocks with the same milling parameters. CAD/CAM posterior ceramic occlusal veneers restorations were cemented using flowable composite material before and after heating. Wear of occlusal veneers using chewing simulator (ROBOTA) with different opposing: human enamel, e. max and v. enamic CAD/CAM discs was used. The effect of wear and flowable composite heating on color stability were measured and the data were tabulated and analyzed statistically.Results: Total effect of heating of composite cement; regardless to occlusal veneers restorations material groups or mechanical wear, it was found that composite resin cement heating affected color stability significantly (p=0.00095 heated composite cement (ΔE) mean value = 4.53). Total effect of mechanical wear; irrespective of occlusal veneer material groups or composite resin cement heating, it was found that mechanical wear affected color stability non-significantly (p=0.5776> 0.05) as indicated three way ANOVA test where ( After aging (ΔE) mean value = 5.38 ≥ before aging (ΔE) mean value = 5.09) Conclusions: selection of the occlusal veneers materials should consider wear properties because the occlusal wear rate varies according to the materials of the occlusal veneers restoration and opposing surfaces as well as the applied load. Moreover, for best aesthetic results, clinicians must be taken in considerations the color, translucency of ceramics and the effects of the luting agent on optical properties.

Color stability of heat polymerized polymethyl methacrylate resin denture base after addition of high molecular nano chitosan

Background: The addition of other ingredients to maintain color stability of heat polymerized polymethylmethacrylate is being developed. One of them is by adding high molecular nano chitosan. Purpose: This study aimed to determine the color stability of heat polymerized polymethyl methacrylate denture base resin after an addition of high molecular nano chitosan. Method: 30 sample pieces of acrylic plate (40x10x2 mm) were divied into 6 groups: control group and groups with the addition of chitosan nano gel percentages of 0.25, 0.50, 0.75, 1.0 and 1.50%. 2 ml chitosan nano gel was added into the mixture of acrylic resin with 23 g : 10 ml (P : L). After the mixture was inserted into a mold and then pressed and cured at 74oC for 120 minutes and then 100o C for 60 minutes. Acrylic plates were then released from the mold and finished. Color stability of acrylic resin were measured using UV-Vis Spectrophotometer and analyzed with a one way Anova. Result: The results showed significant differences in color stability after the addition of high molecular nano chitosan. The best color stability found in 1.0% the addition of chitosan nano gel group, the value was 0.07589 cm-1. Conclusion: The chitosan nano gel can be used to maintain color stability of heat polymerized polymethyl methacrylate denture base resin.

Color stability of denture resins after staining and exposure to cleansing agents

Statement of problemHard denture acrylic resins must maintain color stability to remain esthetic. PurposeThe purpose of this in vitro study was to measure the color stability of denture resins subjected to staining agents and cleaned with denture cleansers Material and methodsForty-five disks (10-mm diameter, 2-mm thick) fabricated from 3 denture resins (light polymerized Eclipse; heat polymerized Lucitone 199 Heat; autopolymerized Lucitone 199 Repair) were stored for 24 hours in 37°C water. After baseline colorimetry measurement were made, the specimens were soaked for 8 hours in a staining agent: coffee, cola, or grape juice. Subsequently, the specimens were soaked for 12 hours in a commercial denture cleanser (Polident, GlaxoSmithKline; Efferdent, Prestige Brands Inc) or water (control). This procedure was repeated every 24 hours. Staining agents and cleansers were replenished every 24 hours. Color change (ΔE) was determined after 2, 4, 6, and 8 weeks (n=5). Results were submitted to analysis of variance and Tukey honest significant difference test (α=.05). ResultsSignificant interaction was found between cleansers and staining agents (P=.006), cleansers and resins (P=.034), and resins and staining agents (P<.001). For the staining agent of grape juice, water allowed more discoloration (ΔE=16.93) than Efferdent (ΔE=14.41) or Polident (ΔE=14.81); Efferdent and Polident effects were not significantly different (P=.761). The Lucitone 199 Repair resin cleaned with water discolored more (ΔE=15.24) than with Efferdent (ΔE=14.14) or Polident (mean ΔE=13.82); the difference between Polident and Efferdent was not significant (P=.566). For Eclipse, grape juice discolored more (ΔE=16.43) than coffee (ΔE=12.23; P<.001) or cola (ΔE=13.78; P=.001); coffee and cola staining were not significantly different (P=.071). ConclusionsEclipse resin stained most, especially in grape juice. Compared with water, Polident and Efferdent reduced discoloration better in Lucitone 199 Repair and grape juice stains. Nevertheless, discolorations in all 3 resins were perceivable, regardless of cleanser.

Color Stability of Teeth Restored with Biodentine: A 6-month In Vitro Study

IntroductionWhite mineral trioxide aggregate (WMTA) has been reported to cause dental discoloration. A previous study on the color stability of 5 calcium silicate–based materials investigated the color stability of Biodentine (Septodont, Saint-Maur-des-Fossés, France) in different experimental environments; however, no data are available on the color stability of teeth restored with Biodentine. In this study, we assessed the color stability under artificial light of ex vivo human teeth restored coronally with WMTA or Biodentine. MethodsCavities were prepared on coronal tooth specimens and restored with WMTA + composite (n = 16), Biodentine + composite (n = 16), or composite alone (control, n = 3). Color was assessed spectrophotometrically at 6 time points (initial, 1 week, 2 weeks, 1 month, 3 months, and 6 months), and color difference values were calculated. Statistical analysis was performed using analysis of variance and the Fisher least significant difference test for which P < .05 was considered statistically significant. ResultsThe WMTA group showed discoloration at 1 week, which increased over time. The Biodentine and control groups showed color stability and were not significantly different from one another. ConclusionsTeeth treated with WMTA exhibited discoloration, whereas those treated with Biodentine maintained color stability throughout the study. However, further in vivo studies are necessary to corroborate these results.

The Effects Catechin on Stability of Grape Anthocyanin – Copigment Complex

The color of anthocyanins is unstable and quickly decolourized by reactions. Thus anthocyanins in living cells may have mechanisms for resistance to maintain color stability. Copigmentation is the main color – stabilizing mechanism. In this study copigmentation of anthocyanin in Seedless Red grape were investigated with catechin copigment. The dependence of the copigmentation process on the heating, UV and copigment concentration was studied. Five levels of copigment concentrations as: 0, 120, 240, 480, 960 (mg/l) were examined. The copigmentation effects increased with copigment contain. During UV irradiation, anthocyanin-copigmentation complex showed higher stability in comparison with anthocyanins. Also UV irradiation has the biggest effect on the copigmentation complex in comparision with heating. Keyword: Anthocyanin, Catechin, Copigment, Heating, Seedless Red

Potential mechanisms of carbon monoxide and high oxygen packaging in maintaining color stability of different bovine muscles

The objectives were to compare the effects of packaging methods on color stability, metmyoglobin-reducing-activity (MRA), total-reducing-activity and NADH concentration of different bovine muscles and to explore potential mechanisms in the enhanced color stability by carbon monoxide modified atmosphere packaging (CO-MAP, 0.4% CO/30% CO2/69.6% N2). Steaks from longissimus lumborum (LL), psoas major (PM) and longissimus thoracis (LT) packaged in CO-MAP, high-oxygen modified atmosphere packaging (HiOx-MAP, 80% O2/20% CO2) or vacuum packaging were stored for 0day, 4days, 9days, and 14days or stored for 9days then displayed in air for 0day, 1day, or 3days. The CO-MAP significantly increased red color stability of all muscles, and especially for PM. The PM and LT were more red than LL in CO-MAP, whereas PM had lowest redness in HiOx-MAP. The content of MetMb in CO-MAP was lower than in HiOx-MAP. Steaks in CO-MAP maintained a higher MRA compared with those in HiOx-MAP during storage. After opening packages, the red color of steaks in CO-MAP deteriorated more slowly compared with that of steaks in HiOx-MAP.

Influence of Light and Oxygen on the Color Stability of Five Calcium Silicate–based Materials

IntroductionDifficult handling, long setting time, and potential discoloration are important drawbacks of white mineral trioxide aggregate (WMTA). The development of Biodentine, a recently developed calcium silicate–based material (CSM), has overcome some of these shortcomings; however, there are no available data on its color stability. A previous study showed that WMTA discolors under light irradiation in an oxygen-free environment. The present study evaluated the influence of light irradiation and oxygen on the color stability of 5 CSMs. MethodsFifteen samples of 5 CSMs (ProRoot WMTA, Angelus WMTA, White Portland Cement [PC], PC with bismuth oxide, and Biodentine) were divided into 5 groups. Each group was exposed to different oxygen and light conditions. A spectrophotometer was used to determine the color of each specimen at 0, 120 seconds, and 5 days. Data were analyzed by using analysis of variance and Tukey honestly significant difference test. ResultsThe materials PC with bismuth oxide, Angelus WMTA, and ProRoot WMTA showed dark discoloration after light irradiation in an oxygen-free environment, which was statistically significantly different from Biodentine and PC. In groups that were exposed to no light irradiation or to an oxygen atmosphere, all materials showed color stability over time, and no significant differences were observed among them. PC and Biodentine maintained color stability in all conditions over time and showed no significant differences. ConclusionsThe combination of light and anaerobic conditions (similar to those in clinical situations) results in differences in color of the tested CSMs during a period of 5 days, of which Biodentine and PC demonstrated color stability.

Effects of vitamin E on color stability and palatability of strip loin steaks from cattle fed distillers grains

The objective of this study was to determine the effect of preslaughter antioxidant supplementation to cattle fed wet distillers grains on carcass yield and quality grade, and on the color stability and consumer acceptability of steaks. Two hundred five crossbred steers were fed 35% wet distillers grains with the supplementation of 4 different levels of α-tocopheryl acetate: 0, 125, 250, and 500 IU•animal(-1)•d(-1) for 97 d. Chuck rolls (n = 69) and strip loins (n = 185) were collected and processed at 4 and 7 d postslaughter, respectively. Chucks were ground and separated into 0.23-kg samples. Strip loins were faced and cut into 2.54-cm steaks and packaged in a polyvinyl chloride overwrapped (PVC) package, a vacuum package, or modified atmosphere packages (MAP) for further color, α-tocopherol, objective tenderness, palatability, and proximate analysis. Color was measured objectively using a HunterLab Miniscan XE spectrophotometer (HunterLab Associates Inc., Reston, VA) and subjectively by a trained color panel, and a consumer panel was used to indicate which treatments affected retail acceptability and purchase decisions. Warner-Bratzler shear force measurements were used for objective tenderness, and a trained panel assessed subjective palatability characteristics. Instrumental color measurements revealed little difference for ground beef in both PVC and MAP packages, but diets with 500 and 250 IU•animal(-1)•d(-1) of vitamin E had a longer (P < 0.05) retention of redness and yellowness in steaks as compared with steaks from animals receiving less vitamin E. Subjective color evaluation for strip steaks indicated that greater vitamin E was more likely (P < 0.05) to maintain color stability, overall acceptability, and consumer purchase preference while decreasing percentage of discoloration. No significant differences (P > 0.10) were observed for objective tenderness and sensory attributes of strip steaks, and no differences (P > 0.10) were observed in protein, fat, and moisture percentages of ground beef. Lipid oxidation analysis indicated that steaks packaged in PVC for 7 d and MAP for 1, 3, and 7 d, and ground beef packaged in MAP and PVC for 0 and 7 d of retail display required greater inclusion of vitamin E (500 and 250 IU•animal(-1)•d(-1)) to remain below the 2.28 mg of malonaldehyde/kg threshold. Ultimately, 500 IU•animal(-1)•d(-1) of vitamin E should be supplemented to cattle fed wet distillers grain-based diets when products are packaged in MAP to maximize retail shelf life.

A technique for indirect fabrication of an implant-supported, screw-retained, fixed provisional restoration in the esthetic zone

This article describes an alternative technique for the fabrication of an implant-supported, screw-retained, fixed provisional restoration in the esthetic zone. After an implant-level impression is made with a polyether impression material, the provisional restoration is fabricated indirectly. This technique is easy, saves time, and has economic advantages, while maintaining color stability and esthetic properties for the provisional restoration. It may be contraindicated for severely misaligned implants that require extensive reduction of the implant temporary abutments and denture teeth laminates.

Advances in Technology of KODAK NEXPRESS Digital Production Color Presses

The stochastic screen has traditionally been used to preserve images with fine features as well as to reduce printing Moir&#xE9; of images that contain input periodic structures. However, the stochastic screen also has experienced more difficulty in maintaining color stability in long press runs. Kodak, using its multilevel printing architecture, has created a new stochastic screening technology, with long-run color stability comparable to that of traditional screens. The new screening process has a unique AM and FM structure consisting of variable dot size, dot shape, dot density, and dot positions. The structure simulates the receptive field structure of the human retina to achieve the desired image smoothness. Kodak's high information capacity, multilevel printing technology in conjunction with nonlinear LED exposure, can further be expanded to production printing with even finer contone-screen printing. This paper will discuss the advances of these technologies.

Stability of flower colors due to anthocyanin-flavone copigmentation in Japanese garden iris, Iris ensata Thunb.

The fading of flower color in bluish purple and reddish purple cultivars of Iris ensata and the in vitro stability of malvidin 3RGac5Gand petunidin 3RGac5G due to copigmentation with isovetixin under different pH conditions were examined. The bluish purple cultivars exhibited higher flower color stability than the reddish purple cultivars 2 days after anthesis. In the absence of isovitexin, malvidin 3RGac5G and petunidin 3RGac5G were not able to maintain color stability except at low pH. However, the color stability of malvidin 3RGac5G and petunidin 3RGac5G was increased by copigmentation with isovitexin under all pH conditions tested. Most remarkable was the stabilization of both anthocyanins due to the copigmentation at pH 4.2–6.2. Therefore, it can be concluded that the stability of flower color in the bluish purple cultivars of malvidin 3RGac5Gand petunidin 3RGac5G type of I. ensata is caused at least in part by the copigmentation between these anthocyanins and isovitexin.