Immersion In Staining Solutions Research Articles

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.

Protection Against Discolouration by Two Over-the Counter Desensitising Products.

To determine in vitro the protection potential against discolouration of two OTC (over-the-counter) desensitising products on enamel and dentin in comparison to a standard toothpaste and water by means of a spectrophotometer. A total of 96 samples of bovine enamel-dentin complex and 48 of bovine dentin were alternatively immersed in red wine, tea, coffee or water after having been treated by a sodium monofluorophosphate- and calcium phosphate-based product (Curodont Protect), an amine fluoride-based toothpaste (Elmex Red), a stannous chloride-based toothpaste (Elmex Protection Erosion) or distilled water (negative control). Initial (T0) and final colour (T1, after 4 weeks of immersion in staining solutions) of each specimen were assessed by a spectrophotometer. Statistical analysis was done by means of repeated measures ANOVA followed by Fisher's LSD post-hoc test. Differences between T0 and T1 were considered stastistically significant at p ≤ 0.05. When enamel samples were measured over a black background, ΔE00 values (T0-T1) varied from 2.2 (SD 0.7) for amine fluoride-based product/water to 53.9 (SD 7.6) for amine fluoride-based-product/red wine. When dentin samples were measured over a black background, ΔE00 values (T0-T1) varied from 5.4 (SD 0.9) stannous chloride based product/water to 61.6 (SD 3.7) amine fluoride-based product/red wine. Specifically, the application of the sodium monofluorophosphate was able to statistically significantly (p ≤ 0.05) reduce discolouration induced by the staining solutions tested only on the enamel-dentin complex, while distilled water and the stannous fluoride-based product were able to statistically significantly (p ≤ 0.05) reduce discolouration induced by the staining solutions tested in pure dentin samples.

Color stability of esthetic coatings applied to nickel-titanium archwires

Abstract Introduction Color stability is an important feature to be considered when using esthetic coated archwires. Objective To evaluate color changes on the surface of esthetic nickel-titanium archwires coated with Teflon (Ortho Organizers, USA) or epoxy resin (Tecnident, Brazil) after immersion in staining solution. Material and method Twelve 20-mm-long wire segments were used for each type of coating, which were mounted as two test specimens with a width of 7 mm each. The buccal surface of the archwires was evaluated for fluorescence and color measurements both at baseline and after immersion in a staining solution for 21 days using the VITA Easyshade® Compact spectrophotometer (Model DEASYC220). Differences in total color change according to coating type were compared using an independent samples t-test (p&lt;0.05). The surface characteristics of as-received coated archwires were assessed using scanning electron microscopy. Result Color changes were observed on the esthetic coatings, with a significant difference between the two brands analyzed. Surface analysis revealed flaws such as wear, pitting, elevations, lack of material, granulation, grooves, cracks, and lack of standardization in the coating process in all as-received archwires, but flaws were less evident in epoxy-resin coatings. Conclusion The two esthetic coatings did not show color stability, but Teflon coatings showed a more intense color change than epoxy-resin coatings.

Color Stability of New Esthetic Restorative Materials: A Spectrophotometric Analysis.

The aim of this in vitro study was to evaluate and compare the color stability of different esthetic restorative materials (one microfilled composite, one nanofilled composite, one nanoceramic composite, one microfilled hybrid composite, one microfilled hybrid composite, one nanohybrid Ormocer based composite and one supra-nano spherical hybrid composite) after exposure to different staining solutions (physiological saline, red wine, coffee). All materials were prepared and polymerized into silicon rings (2 mm × 6 mm × 8 mm) to obtain specimens identical in size. Thirty cylindrical specimens of each material were prepared. Specimens were immersed in staining solutions (physiological saline, coffee and red wine) over a 28-day test period. A colorimetric evaluation according to the CIE L*a*b* system was performed by a blind trained operator at 7, 14, 21, 28 days of the staining process. The Shapiro–Wilk test and ANOVA were applied to assess significant differences among restorative materials. A paired t-test was applied to test which CIE L*a*b* parameters significantly changed after immersion in staining solutions. All restorative materials showed significant color differences after immersion in coffee. Coffee caused a significant color change in all types of tested composite resins. Only Filtek Supreme XTE demonstrated a staining susceptibility to red wine; no other significant differences among the materials were demonstrated. Long-term exposure to some food dyes (coffee in particular) can significantly affect the color stability of modern esthetic restorative materials regardless of materials’ different compositions.

Surface characterization of polymers used in fabrication of interim prostheses after treatment with photopolymerized glaze

The material used for interim prostheses fabrication must present excellent physical properties for greater longevity in the face of environmental conditions, which can occur in the oral cavity. The purpose of this study was to evaluate the effect of a photopolymerized glaze on the physical and mechanical properties of polymers used for the fabrication of interim prostheses, before and after thermocycling and immersion in staining solutions. One hundred samples of composite and acrylic resins were fabricated: Dencor chemically activated acrylic resin (CAAR) (n=20) and heat-polymerized acrylic resin (HPAR) (n=20), Charisma (n=20), Structur (n=20), and Protemp (n=20). A mechanical polishing was performed on half of the samples, and a chemical polishing was performed on the remaining samples. Subsequently, all samples were submitted to thermocycling and immersion in coffee staining solution for 21days. Analysis of color and microhardness, as well as atomic force microscopy (AFM), scanning electron microscopy (SEM), and energy dispersive x-ray spectrometry (EDS) were performed. The data were submitted to repeated-measures analysis of variance (ANOVA), followed by the Tukey test (α=0.05) and the Student t-test (α=0.05). It was verified that the glaze decreased the chromatic alteration values, and increased the microhardness values of the samples, with the exception of the Charisma resin. The samples that did not receive chemical polishing had the greatest number of surface irregularities. This study concluded that the groups with glaze presented less color alteration. In addition, Charisma and Structur resins exhibited the greatest chromatic stability. As to the microhardness, the values were greater when the samples were treated with the glaze, with the exception of the Charisma group.

Colour stainability of indirect CAD–CAM processed composites vs. conventionally laboratory processed composites after immersion in staining solutions

ObjectivesThe aim of this study was to determine, by using a spectrophotometer device, the colour stainability of two indirect CAD/CAM processed composites in comparison with two conventionally laboratory-processed composites after being immersed 4 weeks in staining solutions such as coffee, black tea and red wine, using distilled water as control group. MethodsTwo indirect CAD/CAM composites (Lava Ultimate and Paradigm MZ100) and two conventionally laboratory-processed composites (SR Adoro and Premise Indirect) of shade A2 were selected (160 disc samples). Colour stainability was measured after 4 weeks of immersion in three staining solutions (black tea, coffee, red wine) and distilled water. Specimen's colour was measured each week by means of a spectrophotometer (CIE L*a*b* system). Statistical analysis was carried out performing repeated ANOVA measurements and Tukey's HSD test to evaluate differences in ΔE00 measurements between groups; the interactions among composites, staining solutions and time duration were also evaluated. ResultsAll materials showed significant discoloration (p<0.01) when compared to control group. The highest ΔE00 observed was with red wine, whereas black tea showed the lowest one. Indirect laboratory-processed resin composites showed the highest colour stability compared with CAD/CAM resin blocks. ConclusionsCAD/CAM processed composites immersed in staining solutions showed lower colour stability when compared to conventionally laboratory-processed resin composites. Clinical significanceThe demand for CAD/CAM restorations has been increasing; however, colour stainability for such material has been insufficiently studied. Moreover, this has not been performed comparing CAD/CAM processed composites versus laboratory-processed indirect composites by immersing in staining solutions for long immersion periods.

Color stability of siloranes versus methacrylate-based composites after immersion in staining solutions

The purpose of this study was to determine, by using a spectrophotometer device, the color stability of silorane in comparison with four methacrylate-based composites after being immersed in different staining solutions such as coffee, black tea, red wine, orange juice, and coke, and distilled water as control group. Four restorative methacrylate-based composites (Filtek Z250, TetricEvoCeram, Venus Diamond, and Grandio) and one silorane (FiltekSilorane) of shade A2 were selected to measure their color stability (180 disk samples) after 4 weeks of immersion in six staining solutions: black tea, coffee, red wine, orange juice, coke, and distilled water. The specimen's color was measured each week by means of a spectrophotometer (CIE L*a*b* system). Statistical analysis was carried out performing an ANOVA and LSD Test in order to statistically analyze differences in L*a*b*and ∆E values. All materials showed significant discoloration (p < 0.05) when compared to the control group (immersed in distilled water). The Highest ∆E observed was with red wine, whereas coke led to the lowest one. Silorane showed the highest color stability compared with methacrylate-based composites. Methacrylate-based materials immersed in staining solutions showed lower color stability when compared with silorane. Great differences in ∆E were found among the methacrylate-based materials tested. Although color stability of methacrylate-based composites immersed in staining solutions has been widely investigated, this has not been done for long immersion periods with silorane-based composites.

Color stability and fluorescence of different orthodontic esthetic archwires

To evaluate the color stability of six esthetic archwires at different time periods and their fluorescence. Samples were evaluated after 7, 14, and 21 days of immersion in staining solution. Color measurements were performed by means of a spectrophotometer according to the Commission Internationale de I'Eclairage L*a*b* system, and color changes (ΔE*) and National Bureau of Standards units were computed. The fluorescence of as-received samples was evaluated by two observers and compared with that of a bovine central incisor. Statistical differences were investigated using analysis of variance and Tukey's post hoc test. All brands showed statistically significant color change after 21 days (ΔE* from 1.88 to 12.06). The Optis archwire (fiber-reinforced composite) presented the highest color alteration, although staining was observed only near its ends. The Trianeiro archwire (coated nickel-titanium) and the Ortho Organizers archwire (coated stainless steel) presented with less color change. The Optis archwire was the only one that presented with fluorescence similar to that of bovine teeth. All esthetic archwires assessed showed clinically noticeable color change after 21 days in staining solution. The optical properties of currently available esthetic archwires may not yet be ideal.

Color stability of sealed composite resin restorative materials after ultraviolet artificial aging and immersion in staining solutions

The color alteration of resin-based materials is one of the most common reasons to replace esthetic dental restorations. This study assessed the influence of surface sealant (Biscover) on the color stability of nanofilled (Supreme XT) and microhybrid (Vit-l-escence and Opallis) composite resins after artificial aging. One hundred disc-shaped (6 × 1.5 mm) specimens were made for each composite resin. After 24 hours, all specimens were polished and sealant was applied to 50 specimens of each material. Baseline color was measured according to the CIE L*a*b* system using a reflection spectrophotometer. Ten specimens of each group were aged for 252 h in an ultraviolet (UV)-accelerated aging chamber or immersed for 4 weeks in cola soft drink, orange juice, red wine staining solutions or distilled water as control. Color difference (ΔE) after aging was calculated based on the color coordinates before (baseline) and after aging/staining treatment. Data were analyzed with 2-way ANOVA and Fisher's test (α=.05). The results showed significant changes in color after artificial aging in all the groups (P<.05). Independent of the material studied, red wine resulted in the highest level of discoloration. Intermediate values were found for orange juice, UV accelerated aging, and the cola soft drink. The lowest values of ΔE were found for specimens stored in distilled water. All composite resins showed some color alteration after the aging methods. The surface sealant did not alter the color stability of the tested materials.

Staining of a Conventional and a Nanofilled Composite Resin Exposed in vitro to Liquid Ingested by Children.

ABSTRACTAims and objective : To evaluate and compare the effect of coffee, chocolate drink and food dye on the color stability of conventional composite resin and nanocomposite resin.Design : The study sample consists of microhybrid composite and other nanocomposite of shade B1. 40 disks of each material with a diameter of 18 mm and thickness of 1 mm were prepared before discoloration procedure specimens were measured for L* a* b* values and then 10 specimens of each subgroup were immersed in each of three staining solution. The 10 remaining specimens of each main group were immersed in control solution.Discoloration values were analyzed at baseline, 1 week and 4 weeks following immersion in staining solution. The color and color difference of each specimen were measured by spectrophotometer.L* a * b* values of each specimens were measured 3 times by placing each specimen on the measuring head. Resistance to staining effect is expressed in ΔE unit and was calculated from the mean ΔL* a* and Δb* values for each specimens with the following formula.Equation : ΔE* = [(ΔL*)2 + (Δa*) + (Δb*)2]½.Result : Result of study showed that nanocomposite is more stain resistant and color change ΔE*. Conventional composite demonstrates unacceptable color change ΔE* more especially in specimens immersed in coffee.Conclusion : The result of this study indicated tested conventional composite resin was more susceptible to change in color in various media over an extended period of time as compared to nanocomposite.

Evaluation of Colour Stability of Temporary Fixed Partial Denture Materials : In -Vitro Study

Aim: The aim of this study is to evaluate the color stability of five different temporary fixed partial denture materials against external staining caused by commonly consumed beverages and medicament, using a Spectrophotometer. Materials and methods: Twenty samples of each five materials of which three methyl methacrylate based auto-polymerized resins (DPI selfcure tooth moulding powder, Unifast TRAD, Structur 2SC/QM) and two composite based bis-acryl auto-polymerized resins (Luxatemp Fluorescence, Integrity) , were prepared with a diameter of 30±1mm and 2mm thickness. After immersion in staining solution of synthetic saliva and tea, synthetic saliva and cold beverage, synthetic saliva and Chlorhexidine mouth wash, and synthetic saliva (control), the color measurements were made. Result: Colour measurements were made using reflectance spectrophotometer at baseline and at intervals of 1week, 2weeks, 4weeks, 6weeks and 8 weeks respectively and were

In vitro color stability, stain resistance, and water sorption of four removable gingival flange materials

Statement of problem Evaluation of the color stability of materials used for removable gingival flange prostheses may provide information on their serviceability. Purpose This in vitro study compared the color stability, stain resistance, and water sorption of 4 materials commonly used for gingival flange prostheses. Material and methods Forty-five cylindrical disks (15 mm in diameter and 10 mm thick) were fabricated out of 1 silicone (Gingivamoll), 1 copolyamide (Flexite Supreme), and 2 heat-polymerized acrylic resins (QC-20 and Vertex). Ten specimens of each material were evaluated by a spectrophotometer after 7, 14, 30, 60, 120, and 180 days of immersion in staining solutions of coffee and tea, whereas specimens placed in water and exposed to air, served as controls. Color differences before staining and after storage periods were assessed. Another 5 specimens of each material were tested for water sorption after 56 days. Data for color change (ΔE) and weight difference (ΔW) were analyzed by use of a repeated measures analysis of variance and Scheffe's multiple comparisons (α=.05). Results The coffee solution produced the highest discoloration value in the silicone material (ΔE=7.31 ± 0.57, P<.001), followed by the copolyamide (ΔE=4.22 ± 0.40, P<.001), and 2 acrylic resins. In the tea solution, the copolyamide had the greatest staining (ΔE=2.74 ± 0.56), whereas the other materials had smaller color changes ( P<.001). All investigated materials were relatively color stable (ΔE < 2) when stored in air and water for 6 months. The copolyamide material showed the greatest water uptake, whereas silicone adsorbed the least water ( P<.001). Conclusions All flange materials tested demonstrated color stability in air and water. However, the color changes of silicone and copolyamide materials stored in coffee solution for 180 days were greater than 3 NBS (National Bureau of Standards) units, which would be characterized as appreciable and considered clinically unacceptable.