Immersion In Staining Solutions Research Articles

Evaluation of Color Stability for Two Types of Denture Base Materials: Heat Cured Acrylic and Flexible Resin.

Commonly consumed beverages used by human being daily (Tea & Cola) caused external staining. This study is done to evaluate the color stability for two different types of denture base materials against this external staining caused by (Tea & Cola). Sixty (60) samples were prepared, divided into two groups, 30 samples of heat cure acrylic material & 30 samples of flexible resin material (Valplast). Each group divided into three subgroups 10 samples in each, according to the type of staining solution that immersed in it, (synthetic saliva & tea), (synthetic saliva & Cola), and (synthetic saliva alone as a control). Tea & Cola were mixed with synthetic saliva in order to create intraoral environment to certain extent. Color measurement was made at Baghdad University, Collage of Engineering, using reflected spectrophotometer before immersion (at baseline) & after immersion, at intervals of (24 hours) & (1 week) respectively. The result was a highly significant difference between, heat cure acrylic & flexible resin a t baseline & the (flexible samples) were the higher value in discol oration than (heat cure acrylic samples) regardless the type of s taining solution. Maximum discoloration was seen in (synthetic sal iva & tea) solution for both denture base materials. Followed by (synthetic saliva & Cola) & (synthetic saliva alone) respectively . Both denture base mater ials had a color changes after immersion in staining solution (tea , Cola & synthetic saliva). The color changes, for two materi als, were increased with the increase of immersion time.

Color Stability, Gloss Retention, and Surface Roughness of 3D-Printed versus Indirect Prefabricated Veneers.

The long-term color stability and surface properties of anterior laminate veneers are among the crucial factors affecting the clinical longevity of aesthetic restorations. Novel 3D-printed materials are being introduced as definitive restorative treatment. In light of the existing variety of indirect yet minimally invasive composite resin veneers, research on their surface properties is warranted. This in vitro study evaluated the effect of artificial aging by immersion in different staining solutions on the color changes, gloss, and surface roughness (Ra) of 3D-printed veneers compared to the prefabricated resin composite veneer systems (PRCVs) manufactured by Componeer and Edelweiss. Moreover, this study compared the effects of two methods for stain removal: repolishing with Sof-Lex disks and in-office bleaching with 40% hydrogen peroxide. The veneers (n = 24) were randomly divided according to the immersion solutions used, i.e., tea and coffee. Colorimetric measurements, surface roughness, and surface gloss were determined before and after staining and surface treatment with either in-office bleaching or surface polishing. The data were statistically analyzed using two-way ANOVA followed by the Tukey's post hoc test (α = 0.05). Artificial aging with immersion in staining solutions led to significant color changes, increased surface roughness, and gloss reduction in all materials (p < 0.05). The 3D-printed veneers showed higher ΔE values (coffee = 10.112 ± 0.141) and (tea = 10.689 ± 0.771) compared to baseline after 7 days of aging. The 3D-printed veneers had a statistically significant surface roughness Ra (0.574 µm ± 0.073). The gloss was >70% in all groups at baseline; these values dropped in all groups after 7 days of artificial aging. After the stain-removing procedures, the ΔE values decreased in all tested veneers. That being said, they failed to return to the baseline values, and both stain-removing methods were found to have an adverse effect on surface roughness and gloss retention in all tested veneers.

Effect of chemical or mechanical finishing/polishing and immersion in staining solutions on the roughness, microhardness, and color stability of CAD-CAM monolithic ceramics.

To evaluate the effects of various surface treatments and immersion in coloring substances on the roughness, microhardness, and color stability of CAD-CAM monolithic ceramics. The ceramics used were lithium disilicate reinforced with zirconium dioxide (Suprinity), lithium disilicate (E.max) or leucite (Empress). They were subjected to two surface treatments: glazing (group G) (n=20) or mechanical polishing (group P) (n=20). Then they were divided into two subgroups (n=10) to be treated with the staining substance (coffee or water). Roughness, microhardness and color were measured before and after treatment. Data were subjected to analysis of variance and multiple comparisons were performed with Tukey tests at 5% significance level. Roughness was lower in all tested ceramics after polishing than after glazing. Microhardness was the same for polished and glazed E.max, higher in glazed than polished Empress, and higher in polished than glazed Suprinity. Analysis of the effects of glazing and polishing on the individual ceramics showed that the ΔE2000 and ΔWID data of the E.max ceramic subjected to polishing showed greater change. Mechanical polishing is a good option for surface treatment of monolithic ceramics. Glazing was inferior and less satisfactory than polishing. Glazing generates changes that can lead to color instability.

Comparative Efficacy of Four Stain Removal Methods for Bleach-Shade Composite Resins after Immersion in Staining Solutions: An In Vitro Study.

Bleach-shade composite resins were recently introduced to the market due to the high demand of patients for whiter teeth. This study sought to compare four stain removal methods for bleach-shade composite resins. Seventy-two discs were fabricated from each of the Filtek Z350 XT and Gradia XBW composite resins and immersed in coffee or sour cherry juice staining solutions. Each group was then divided into four subgroups to assess the efficacy of four stain removal methods (finishing with soft-lex disk "brush with pumice" bleaching with carbamide peroxide 16%, bleaching with hydrogen peroxide 40%). The color of each specimen was measured by Easyshade spectrophotometer, and data were analyzed using SPSS 25 statistical package for social sciences. The home-bleaching technique was more effective than the office-bleaching and pumice for the removal of sour cherry juice stain (ΔE = 1.93) and coffee stain (ΔE = 3.32) from Gradia composite discs, almost returning the baseline original color. The Sof-Lex discs were more effective than the pumice for the removal of sour cherry juice stain (ΔE = 4.11) and coffee stain (ΔE = 4.93) from Z350 composite discs but not return the baseline original color. Filtek Z350 had more discoloration than Gradia Direct. The different materials and solutions reacted differently to the four stain removal methods. In GCJ group after all stain removal methods, ΔE reduced to a clinically acceptable level.

The Effect of Different Immersion Media, Polymerization Modes, and Brushing on the Color Stability of Different Composite Resins.

This in vitro study investigated color stability of two photo-polymerized nano-filled and nano-hybrid composite resins in different polymerization modes immersed in different staining solutions before and after brushing. Disc-shaped specimens (n = 120) were prepared from two composite resins based on filler particle size: nano-filled (Filtek Z350, shade A1, 3M ESPE) and nano-hybrid (Spectra ST-HV, shade A1, Dentsply Sirona) composite resins (n = 60 per composite type). Specimens of each resin type were photopolymerized using the following polymerization modes: LED conventional, ramp, and pulse (n = 20 specimens per resin type and LED mode). After preparation, baseline color of the specimens was evaluated using a spectrophotometer (Easyshade V, VITA), and color change was evaluated using the CIE L*a*b* formula. Specimens were soaked in distilled water for 4 weeks in separate containers. The specimens from each polymerization-mode group were separated into two groups of 10 specimens; one group was stored in tea and the other group was stored in cola, each 1 hour daily for 4 weeks. After 4 weeks, the color was measured again. The specimens were brushed for 2 minutes under 200-g weight using an electronically powered toothbrush on the polymerized side of the specimen. The color was reevaluated immediately after brushing. Color-difference data (ΔE) between groups were analyzed by one-way analysis of variance for main comparison and by independent t test for color change after brushing. Nano-filled composite resin was more color-stable than nano-hybrid composite resin (P < .001), regardless of the staining media. For both composite resin types, the conventional polymerization method produced a more color-stable result (P < .0001). ΔE after brushing was reduced significantly (P < .0001). Both staining solutions have significant effects on color change, with tea staining more than cola (P < .0001). Nanofilled composite resin had greater color stability than nano-hybrid composite resin after immersion in staining solutions. Polymerization mode influences the color stability of both composite resin types. Int J Periodontics Restorative Dent 2023;43:247-255. doi: 10.11607/prd.6427.

Color changes of esthetic elastomeric ligatures due to exogenic pigmentation

Vytautas Sabataitis1, Vilija Berlin2 1Institute of Odontology, Medical Faculty, Vilnius University, Vilnius, Lithuania 2Vilnius University Hospital Zalgiris Clinic, Vilnius, Lithuania Abstract Backround and aim of the work: a contemporary patient seeks to achieve the most aesthetically pleasing orthodontic treatment therefore chooses colorless elastic ligatures instead of metal ligatures. However, elastic ligatures tend to change their color due to food colorings and impair esthetics. Aim of this study is to evaluate and compare in vitro color change due to staining solutions of the most frequently used aesthetic orthodontic elastic ligatures offered by different companies in Lithuanian market. Materials and Methods: fourteen different types ligatures were immersed for 72 hours in four different solutions: distilled water (control), coffee, black tee, and wine. Ligatures’ color change was measured with spectrophotometer and evaluated by the Commission Internationale d’Éclairage color system and National Bureau of Standards units Results: Coffee was the most staining solution. Color change of all ligatures were from 4,32 (appreciable) to 24,71 (change to another color). Statistically significant and the smallest color change was observed in these ligatures: “Tooth” (GC), “Tooth” (America Orthodontics) and “Clear” (3M) with “Pearl” (American Orthodontics). The biggest color change was observed in “Clear” (American Orthodontics), “Clear” (GC), “Clear” (Ormco) and “Tooth” (Ormco) ligatures after the immersion. In group of all “Clear” ligatures only elastic ligatures by 3M showed statistically significant smallest colour alteration (p<0,01). Conclusion: all tested elastic orthodontic ligatures change their color after immersion in staining solutions and the color alteration is perceptible by human eye. Statistically significant color change between different types of ligatures was found. Keywords: Easthetic orthodontic, orthodontic appliances, Orthodontic ligatures.

Color Stability of Different Denture Teeth Following Immersion in Staining Solutions.

Objectives: This study aimed to assess the color change (∆E00) of 7 brands of denture teeth (conventional acrylic and composite teeth) following immersion in staining solutions. Materials and Methods: Maxillary central incisor denture teeth made of 4 conventional acrylic resins (Vitapan, SR Vivodent PE, Beta Star and Crystal) and 3 composite resins (Finex, Emeral and Phonares II) were randomly divided into four groups (n=5). Denture teeth of different brands were immersed in tea, coffee, cola, and turmeric solutions. The solutions were incubated at 37°C. The baseline color of the teeth was measured using an intraoral spectrophotometer. The color of the teeth was measured after 24 h (∆E12), 1 week (∆E13), 2 weeks (∆E14), and 1 month (∆E15). ∆E00 was calculated and analyzed using one-way ANOVA. Pairwise comparisons were performed by the Tukey’s post-hoc test (P<0.05). Results: The color stability of all teeth was significantly affected by the solutions (P<0.001). The type of tooth and coloring solution had significant interactions at all times (P<0.05). Turmeric caused the maximum color change in all teeth after 1 month. Repeated measures ANOVA showed that ∆E00 of all teeth was significantly affected by the duration of immersion in the solutions (P<0.001). Conclusion: within the limitations of this study, 1-month immersion of denture teeth in coffee, tea and cola solution altered the ∆E values; however, they were within the acceptable range, except for Beta Star. Turmeric solution caused unacceptable color change in all denture teeth even after 24 h of immersion.

Evaluation of the colour and translucency parameter of conventional and Computer-aided design and computer-aided manufacturing (CAD-CAM) feldspathic porcelains after staining and laser-assisted bleaching.

Aims:The present study aimed to evaluate the color and translucency changes of the feldspathic porcelain samples made using the conventional or computer-aided design/computer-aided manufacturing (CAD/CAM) methods after immersion in staining solutions and laser bleaching.Materials and Methods:A total of 72 samples of feldspathic porcelain were fabricated using the conventional (n = 36) or CAD/CAM (n = 36) methods. Afterward, each group was randomly divided into three subgroups (n = 12), which underwent exposure to coffee, orange juice, or distilled water for 6 weeks. Then, the samples underwent diode laser-assisted bleaching. A spectrophotometer assessed the samples’ color and translucency preintervention, after staining, and after bleaching.Statistical Analysis Used:One-way and two-way analysis of variance and independent t-test were used. The significance level was 0.05.Results:Staining for 6 weeks significantly changed the color of both types of feldspathic porcelains. Furthermore, there were significant differences between the ceramics made using different methods and immersed in different staining solutions (P < 0.001). Furthermore, laser-assisted bleaching changed the color of immersed specimens significantly (P = 0.005). However, there were no significant translucency changes in all the subgroups after staining (P = 0.215) and laser bleaching (P = 0.325).Conclusions:The staining-induced discoloration of all the subgroups was in the clinically acceptable range (ΔΕ<3.3). In addition, bleaching could effectively remove the stains in both types of ceramics while not affecting the primary color. Moreover, the translucency of the ceramics was not affected by staining or laser-assisted bleaching.

Color Stability of Dental Reinforced CAD/CAM Hybrid Composite Blocks Compared to Regular Blocks.

This study compares the color stability of dental reinforced computer-aided design/computer-aided manufacturing (CAD/CAM) hybrid composite blocks to that of regular blocks. One hundred fifty disc-type specimens (n = 15) were prepared from five sets of hybrid composite blocks (Cerasmart-200/Cerasmart-300, KZR-CAD HR/KZR-CAD HR3, Estelite Block/ Estelite-P Block, Avencia Block/Avencia-P Block, Mazic Duro/Duro Ace). The specimen color and translucency parameter (TP) were assessed using a spectrophotometer before and after immersion in staining solutions (water, 10% ethanol, simulated red wine). Changes in color (ΔE) and translucency (ΔTP) of specimens were calculated. The data were analyzed using the analysis of variance (ANOVA) and Tukey’s post hoc test (p < 0.05). Microstructural features of the hybrid composite blocks were also examined using FE-SEM. Immersion in deionized water or 10% ethanol made no significant color or translucency changes (except for Avencia-P Block); however, the simulated red wine caused significant changes to the color and translucency of almost all specimens, especially after 4 weeks of immersion. The reinforced hybrid blocks (except for Estelite-P Block and Duro Ace) showed lower color stability than corresponding regular blocks. Avencia-P Block showed significantly reduced color stability compared to Avencia Block. Even in deionized water and 10% ethanol, Avencia-P Block showed perceptible ΔE and decreased translucency. Estelite Block/ Estelite-P Block and Mazic Duro/Duro Ace showed better color stability than the other materials tested.

Color Stability of Artificial White Spot Lesions treated with Resin Infiltration

Objective: To evaluate the color stability of artificial white spot lesions treated with three different surface treatments after immersion in staining solution. Materials and Methods: An artificial white spot lesion was created in the middle of the labial surface using demineralizing solution. Sixty-five bovine teeth were randomly assigned into 5 groups (n=13) according to surface treatment. G1: Enamel submitted to demineralization only. G2: Polished Enamel. G3: Demineralized enamel treated with low-viscosity resin infiltrant. G4: Demineralized enamel treated with CPP-ACP for 1 month. G5: Demineralized enamel treated with Artificial saliva for 1 month. All specimens were then immersed in a staining solution (coffee) for 8 weeks. Color measurements, using the CIE L*a*b* system, were done immediately after treatment and after 2, 4 and 8 weeks of immersion, by Spectrophotometry. Digital photographs were also taken at each stage to a representative specimen from each group. In addition, representative specimen for each group was evaluated using Polarized Light microscope. Color change (ΔE) was analyzed by two-way mixed ANOVA. Results: Resin infiltrant group exhibited the lowest color change values at all times of measurement, followed by CPP-ACP and polished enamel, while the highest color change values were recorded in samples without treatment. Conclusion: Resin infiltrant can be considered an effective treatment in masking and reducing long-term staining susceptibility of white spot lesions after treatment.

COLOR STABILITY AND SURFACE ROUGHNESS OF AN ORGANICALLY MODIFIED CERAMIC (ORMOCER) AND A METHACRYLATE BASED COMPOSITE RESINS (AN IN-VITRO STUDY)

Introduction: Any esthetic restorative material largely depends on the color match and the color stability of the material in long term use. Also the smooth surface appear to be critical for composite performance and it's aesthetic outcome. However resin composites are materials that can show color changing when exposed to staining media. Objectives: The aim of this invitro study is to evaluate the color stability, change in opacity and change in surface roughness of an ORMOCER, and two methacrylate based composites after being immersed in different staining solutions with different time intervals. Materials and methods: A total of one hundred twenty disc specimens (10mm in diameter and 2mm in thickness) were prepared from three composite resins, A bulk fill ORMOCER based (Admira fusion X-tra) and a bulk fill methacrylate based (X-tra fill) and an incremental fill methacrylate based (Esthet-X HD) composite resins (n = 40). Specimens of each type were divided in to four groups according to immersion solutions (n = 10). Group A= Specimens were immersed in coffee (Nescafe classic, Nestle, Egypt), Group B= Specimen were immersed in tea (Lipton yellow lable, Unilever brand, Egypt), Group C = Specimen were immersed in cola (Coca cola company, Egypt) and Group D= Specimen were immersed in distilled water as a control group. Color evaluation was done at base line before staining and then at periods of 7 days, 14 days, 28 days using spectrophotometer. Change in color (∆E*) and opacity (∆Op) were obtained using the CIE L*a*b* system. Surface roughness was evaluated using Atomic Force microscopy at baseline before staining and then at 28 days from immersion in staining solutions. Results:All composite used showed change in color values at the end of the time intervals after 28 days of immersion in staining solutions. Group A (coffee) was the highest effecting group (ΔE >3.3) and Admira fusion X tra was the material with the highest change in color. Surface roughness also increased especially in group C (cola) for all materials after 28 days with no statistically significant difference between groups (p>0.05). Conclusions: Coffee has a higher effect on staining composite resin than tea and cola. While cola affected the surface roughness of the composite resins used more than the other solution used.

Evaluation of the effect of tooth polishing on color stability after in-office bleaching treatment

Abstract Introduction One of the most commonly used corrective methods for staining teeth is tooth bleaching. However, subclinical alterations may occur in the micromorphology of dental tissues during the bleaching procedure, such as increases in porosity and surface roughness. Consequently, dental enamel may become more permeable and susceptible to staining. Objective To evaluate the influence of tooth polishing after in-office bleaching treatment on color stability. Material and method Thirty-three extracted human molars were used. The teeth were cut in the mesiodistal direction to obtain two samples per tooth (total of 66). The samples were randomly divided into six groups (n=11). Before and after the bleaching treatment, the lightness of the samples and change in lightness (∆L) were determined with a digital spectrophotometer (Easy Shade). The samples were bleached with 35% hydrogen peroxide (three sessions weekly). Three groups were submitted to polishing with felt discs and polishing paste after each session. To simulate the oral conditions during the consumption of colored beverages, the samples were submitted to alternating cycles of immersion in staining solutions (coffee, red wine, and Coca Cola). Result Polishing resulted in an increase of mean lightness of 4.49 in the red wine group, 2.73 in the coffee group, and 4.08 in the cola group. The difference was significant in the red wine group (p&lt;0.022), but not in the coffee or cola group. Conclusion Polishing after in-office bleaching using felt discs and polishing paste can reduce the degree of pigment impregnation in patient with red wine rich diet.

Influence of Staining Solutions on Color Change and Enamel Surface Properties During At-home and In-office Dental Bleaching: An In Situ Study.

The purpose of this in situ study was to evaluate the influence of staining solutions (coffee and cola) on the color change, microhardness, roughness, and micromorphology of the enamel surface during at-home and in-office dental bleaching. One hundred and thirty-five enamel bovine blocks were prepared to perform the evaluations. Fifteen volunteers used an intraoral appliance with nine enamel blocks for 15 days. The enamel blocks were randomly assigned among the different groups according to the three treatments: in-office bleaching with high hydrogen peroxide concentration (Opalescence Boost PF 40%, Ultradent) for 40 minutes in three sessions (first, eighth, and 15th days of treatment), at-home bleaching with low carbamide peroxide concentration (Opalescence PF 10%, Ultradent) for 60 minutes daily for 15 days, and a control group (no bleaching agent applied). The enamel blocks were immersed daily in different staining solutions (coffee or cola) for 30 minutes for 15 days or were not submitted to staining (control) to obtain a factorial scheme (3×3) of the dental bleaching treatment and staining solution (n=15). The microhardness analyses (Knoop), roughness evaluations (Ra), surface micromorphological observations, and color measurements (using the CIELAB system and the VITA Classical scale) were made before and after the bleaching treatments to assess immersion in staining solutions. Mixed model tests showed that there was a decrease in enamel microhardness after exposure to cola compared with coffee and the control group (p<0.0001) for both bleaching techniques. Roughness was higher for the cola groups (p<0.0001), and there was no significant difference between the coffee and the control groups. Generalized linear models showed that when no staining solution was applied, lighter color scores were found for the VITA Classical scale (p<0.0001). Without the staining solutions, there was an increase in luminosity (ΔL) (p=0.0444) for in-office bleaching. Lower values of Δa (p=0.0010) were observed when the staining solutions were not used. The Δb (p=0.3929) did not vary significantly between the bleaching agents, but when cola was applied, the values were significantly higher than for the control (p=0.0293). Higher values of ΔE (p=0.0089) were observed for in-office bleaching without staining solutions, while lower values of ΔE were observed for the in-office associated with coffee immersion. Regardless of whether being submitted to bleaching, the enamel stained with cola showed a decrease in microhardness, an increase in roughness, and changes in the micromorphology. The efficacy of the bleaching agents was greater when no staining solution (cola or coffee) was used, and in-office bleaching showed greater color change than the at-home bleaching technique.

Spectrophotometer analysis of bulk-fill composites on various beverages: An in-vitro study

Spectrophotometer analysis of bulk-fill composites on various beverages: An in-vitro study - IJCE- Print ISSN No: - 2581-9534 Online ISSN No:- 2581-8988 Article DOI No:- 10.18231/2456-8953.2019.0004, IP Indian Journal of Conservative and Endodontics-IP Indian J Conserv Endod

Polishing Methods' Influence on Color Stability and Roughness of 2 Provisional Prosthodontic Materials.

To evaluate the roughness and color change of a conventional acrylic resin and a bis-acryl resin, submitted to different types of polishing and exposed to a staining solution. One hundred specimens were manufactured from an autopolymerizing conventional acrylic resin (Duralay, shade 66) (n = 50) and a bis-acryl resin (Protemp 4, shade A3) (n = 50) according to the manufacturers' instructions. Specimens were subdivided into 10 groups (n = 10), according to the type of resin and polishing method, including no-polishing (control groups for acrylic resin [tungsten bur finishing] and bis-acryl resin [cotton and alcohol]), Enhance System, Edenta kit, Labordental kit, and sandpaper. The specimens were immersed in a staining solution (coffee at 60°C) for 7 days. Surface roughness was evaluated before the first immersion (baseline - Ra1) and after 7 days (Ra2). The color change (∆E) was determined after 24 hours (∆E1) and 7 days (∆E2), by CIE L* a* b* scale. Data were statistically analyzed with 3-way ANOVA for repeated measures test and Tukey test (α = 0.05). According to 3-way ANOVA test, material, polishing techniques, and polishing*material factors exhibited statistically significant influence (p < 0.0001) on the roughness, and, for color change, material, polishing techniques, time, polishing*material, and material*time factors were statistically significant (p < 0.0001). The polishing techniques successfully reduced the surface roughness of acrylic resin groups, when compared to control (p < 0.001), but for bis-acryl resin, results were not different from the control group (Enhance: p = 0.954, Edenta: p = 0.866, sandpaper: p = 0.366, Labordental: p = 0.945). Surface roughness was not affected by the immersion in staining solution for 7 days. Color change of acrylic resin groups after 24 hours and 7 days of immersion exhibited a clinically acceptable value (ΔE < 3.7) with the exception of the Enhance group, and all bis-acryl resin groups exhibited a clinically unacceptable color change value (ΔE > 3.7) independent of polishing technique and time interval (∆E1 and ∆E2). Roughness of both materials was similar when the polishing techniques studied were performed, although Ra values were superior to the clinically acceptable values (0.20 µm), and were not affected by the immersion protocol studied; however, when esthetics are critical, the selection of material type is more important than the surface treatment technique used, and bis-acryl resin was more susceptible to clinically unacceptable color change after immersion in a staining solution.

Effect of different surface treatments on the alteration of color of ceramic

The objective of this study was to evaluate the effect of different surface treatments on the pigmentability of the ceramic after immersion in staining solution. 44 disks of 10 mm radius and 3 mm thickness were made. Samples were randomly assigned among 4 experimental groups (n=11) receiving surface treatment according to the different groups M, H, B, L. (n=10) were distributed for color evaluation and Roughness (RU) and a sample of each group used for scanning electron microscopy (SEM) analysis. For (RU), the data were subjected to ANOVA on ranks (α=0.05), and for the color ANOVA a factor (α=0.05). In the microphotographs of the surface, a qualitative/descriptive analysis was carried out. Results: In the (RU) compared before and after immersion for each group, no statistical difference was observed (p> 0.05). When comparing the types of polish before immersion, a difference was observed between the L group with the other M, H, B (p <0.05). In the analysis of the groups after immersion, there was a difference of group L with B and M (p <0.05). When comparing the color alteration, after immersion, there was a difference between all the ANOVA groups (p <0.05). In the analysis by (SEM) all groups had partially porous surfaces; however, the varnishes produced the best result groups H and B.The texture of the surface is an important factor in the pigmentability of ceramics. the varnished materials showed less color alteration.

Color Stability of Acrylic Resin Teeth After Immersion in Staining Solutions

Color Stability of Acrylic Resin Teeth After Immersion in Staining Solutions

Evaluation of Nanomechanical Properties, Surface Roughness, and Color Stability of Esthetic Nickel-Titanium Orthodontic Archwires.

Objectives:The objective of the study is to evaluate the surface roughness, nanomechancial properties the color stability of three brands of coated (rhodium, epoxy, and Teflon) nickel-titanium (NiTi) esthetic archwires.Materials and Methods:Three brands of coated (rhodium, epoxy, and Teflon) esthetic NiTi archwires and three brands of uncoated (NiTi) archwires from the same manufactures were evaluated for the surface roughness, nanomechanical properties, and color stability. The specimens with 20 mm length (n = 5) were cut from the straight buccal segments of the coated and uncoated archwires. The specimens with 20 mm length (n = 10) were subjected to color measurement after immersion in a coffee staining solution. The color measurement was evaluated after 7, 14, 21, and 28 days after immersion in staining solution using color eye 7000 spectrophotometer. The experimental data were analyzed using descriptive statistics, analyses of variance, and Tukey's post hoc test.Results:Epoxy (1.517 ± 0.071) and rhodium (0.297 ± 0.015) coated archwires showed the highest and lower value of surface roughness. All the intergroup comparisons showed a significant difference (P < 0.05) in surface roughness except between rhodium and control group (P = 0.998). There were significant differences between control and the experimental groups for both nanohardness and elastic modulus was observed. All the three NiTi-coated esthetic archwires demonstrated trace” (extremely slight change) color changes as measured by the National Bureau of Standards units after 4 weeks of immersion.Conclusion:Surface roughness of rhodium-coated archwires was almost similar to that of uncoated wires. Whereas Teflon and epoxy coated archwires showed a significant difference in surface roughness compared to uncoated archwires. Uncoated archwires showed higher nanohardness values compared to the coated archwires. Teflon-coated archwires demonstrated significantly slight color change after 4 weeks of immersion in staining solution.

STUDY OF COLOR STABILITY OF SOME DENTURE TEETH MATERIALS

Objective: To study the color stability of some denture teeth materials (acrylic &porcelain) and to evaluate some mechanical properties of these denture teeth materials. Material and methods: Forty samples of both acrylic and porcelain teeth were immersed in three staining solutions and distilled water. Color measurements were performed by using spectrophotometer. Before immersion, the initial color value of each tooth was recorded. Color change values were determined after 1 day, 1 week, 2 weeks, 4weeks and 6 weeks of immersion. Color differences were characterized using the CIE L*a*b* color space. Also water sorption and surface roughness were evaluated. Results: showing significant color changes of the different denture teeth materials upon immersion in tea, coffee, cola, or distilled water. This color change was greater in case of immersion in either tea or coffee solutions. The least color change was obtained from samples immersed in distilled water. The different materials used showed no significant statistical difference in water sorption values. Finally the results showed that, there were significant statistical differences in surface roughness of all tested materials after immersion in any of the tested solutions. Conclusion: The acrylic denture teeth material is much more subjected to discoloration than the porcelain denture teeth material. Water sorption of the tested materials was of close values. Surface roughness of the denture teeth material show significant statistical difference by immersion in staining solutions

Color stability of different composite resins after polishing.

The goals of the present study were to evaluate, in vitro, the staining of different composite resins submitted to different common beverages, and to compare the staining effect of each of these solutions. A total of 288 specimens were randomly divided into six groups and immersed for 4weeks in five staining solutions represented by red wine, orange juice, coke, tea and coffee or in artificial saliva as a control group. When analyzed over a black background, mean ΔE00 values varied from 0.8 for Venus Diamond, Saremco Microhybrid and ELS in saliva and Estelite Posterior in coke to 37.6 for Filtek Supreme in red wine. When analyzed over a white background, mean ΔE00 values varied from 0.5 for Saremco Microhybrid in saliva to 51.1 for Filtek Supreme in red wine. All materials showed significant changes in color after 4weeks of immersion in staining solutions. Significant differences were found between the tested composite resins and also between the staining solutions.