Staining Beverages Research Articles

Surface Quality Evaluation of Removable Thermoplastic Dental Appliances Related to Staining Beverages and Cleaning Agents

(1) Background: Thermoplastic materials are not inert and subject to changes in the oral environment, which affect their surface quality. Color stability and topographic characteristics of clear thermoplastic appliances are critical considerations. The study aimed to evaluate the optical changes and surface topography of different thermoplastic materials related to staining beverages and cleaning agents. (2) Methods: Thermoplastic polyethylene terephthalate glycol (PET-G) material specimens were selected for the study: S (Duran, Scheu-Dental GmbH, Iserlohn, Germany), D (Biolon, Dreve Dentamid GmbH, Unna, Germany), and B (Crystal, Bio Art Dental Equipment, Sao Carlos, Brazil). Four different media were involved for immersion: coffee (C) and black tea (T) at 55 °C, Coca-Cola (K) at 5 °C, and distilled water (W) at 22 °C. As for cleaning, chemical options and mechanical brushing were selected (P-powder, T-tablets, and X-brushing). Color changes, and mean surface roughness were measured at 24 h, 48 h, and after 7 days. Statistical analysis was performed. After the testing period, atomic force microscopy (AFM) analyses and SEM images were registered in order to characterize the surface topography. (3) Results: Quantitative color change evaluations revealed a slight change in color after 24 h and an extremely marked change after 48 h, respective 7 days. Mean roughness values are kept below the clinically acceptable limit of 0.20 µm for all samples. Related to mean nanoroughness values Sa, and 3D evaluations of the surface quality, Biolon samples have demonstrated the most constant behavior, while Crystal samples are visibly influenced by water immersion. Related to the cleaning method, the topography of Duran samples was influenced by mechanical brushing. (4) Conclusions: Nanoscale investigations provided high accuracy and more realistic surface quality examinations of the examined samples compared to profilometry. Both SEM and AFM should be used for a more detailed description of the surface topography.

Thermoplastic Disks Used for Commercial Orthodontic Aligners: Complete Physicochemical and Mechanical Characterization.

Invisible orthodontic aligners (IOAs) have been introduced in the orthodontic field as an innovative alternative for fixed brackets, in relation to their ability to be easily inserted/removed from the oral cavity without affecting the chewing ability and the aesthetic of the patients. The paper provides a complete physicochemical and mechanical characterization of thermoplastic materials in the form of disks used for commercial IOAs. A wide palette of specific techniques is considered, from tensile tests and dynamic-mechanical analysis, to X-Ray diffraction (XRD), differential scanning calorimetry (DSC), Fourier transformation infrared spectroscopy (FTIR-ATR) analyses and water absorption tests. The disks are investigated before and after immersion into staining beverages (red wine, coffee, nicotine and artificial saliva), in terms of colour variations, transparency, and microscopic surface modifications by means of colorimetry, UV-VIS absorbance and scanning electron microscopy (SEM). Among all the samples, polyurethane (PU) exhibited the highest crystallinity and the highest values of mechanical and thermal resistance, while the poly(ethylene terephthalate)-glycol (PETG) samples presented better transparency and less ability to absorb water. Moreover, red wine and coffee give noticeable colour variations after 14 days of immersion, together with a slight reduction of transparency.

Effect of different beverages and storage period on bis‐acryl color stability using two assessment methods

This study aimed to evaluate the color stability (ΔE00 ) of bis-acryl resins after different immersion solutions and storage time by different evaluation methods. Sixty specimens (n = 30) were prepared from Protemp 4 and Structur 3. The specimens were divided into three groups (n = 10), according to the immersion solution (artificial saliva, cola beverage, and yerba mate tea) and evaluated at two storage times (7 and 14 days). The ΔE00 of each group was calculated using color coordinates obtained by a spectrophotometer and by a digital method, using the CIEDE2000 color difference formula. Data were analyzed by three-way ANOVA and Tukey test (α = 0.05). The 7-day period presented the lowest ΔE00 values, regardless of the material and solution evaluated for both evaluation methods (ΔE00 < 0.93; ΔE00 < 3.12). The immersion solution with the highest color change was yerba mate tea after 14 days (ΔE00 > 2.11). For digital analyses, all materials and solutions at both times presented ΔE00 values higher than the clinically acceptable (ΔE00 > 1.8), while in spectrophotometer only in yerba mate tea (14 days) Structur was above the clinical acceptability level. Yerba mate tea was the immersion solution with a higher color change in both materials and assessment methods. The highest values were found after 14 days of immersion, regardless of the solution. The ΔE00 for the digital method was higher than the spectrophotometer analysis. It is important to identify the influence of staining beverages on interim materials used in patients requiring temporary rehabilitation. The use of a spectrophotometer seems to be more accurate than the digital method for the evaluation of color parameters of the tested materials.

Stainability of acrylic resin materials used in CAD-CAM and conventional complete dentures

Statement of problemThe effect of staining beverages on the color of dentures made with computer-aided design and computer-aided manufacturing (CAD-CAM) is unknown. PurposeThe purpose of this in vitro study was to evaluate the stainability of acrylic resins used in CAD-CAM–fabricated complete dentures compared with conventional materials. Material and methodsAcrylic resin denture teeth from 3 different manufacturers (2 conventional and 1 milled) were obtained (N=45). Denture base acrylic resin specimens were made with 3 different techniques (compression molding, injection molding, and milling) (N=45). Conventional and/or milled acrylic resins were used to make specimens comprising both denture teeth and denture base acrylic resins (4 conventional, 2 milled denture bases with bonded teeth, and 1 all-milled) (N=105). All specimens were then immersed in coffee, red wine, or distilled water as control. The CIELab color differences between before and after immersion were determined by using a VITA Easyshade spectrophotometer. The tooth-denture base interface of the denture blocks was evaluated visually for the presence of stain. The CIELab data were analyzed by using ANOVA, and chi-square test was used for visual assessment (α=.05). ResultsSignificant interactions were found between each acrylic resin material and each staining solution immersion when compared with distilled water immersion (P<.001). Denture teeth had similar color change after immersion in coffee (P=.149), while the most pronounced color change was observed with Portrait teeth upon immersion in wine (P<.001). Injection-molded denture base specimens exhibited less color change upon staining in wine than compression-molded or milled specimens (P<.001). Upon staining in coffee, milled specimens were not significantly different from injection- (P=.053) and compression-molded specimens (P=.180). The chi-square test showed a significant association between processing technique and stain accumulation at the tooth-denture base interface when evaluated visually (P<.001). Stain accumulation was greatest with compression-molded specimens (58%), followed by injection-molded (43%) and milled specimens with bonded teeth (8%). Monolithic teeth with milled denture base had no stain deposits at the tooth-denture base interface. ConclusionsThe stainability of milled acrylic resins was no better than that of conventional materials. However, CAD-CAM milled denture blocks with teeth and base acrylic resins had greater resistance to stain accumulation at the tooth-denture base interface than those of conventional processing methods.

Influence of composite type and light irradiance on color stability after immersion in different beverages.

The aim of this study was to evaluate the color stability of two resin-based composites photo-activated by two light curing units (LCU) with different irradiances. Hundred disc-shaped specimens (2-mm thick) of a nanofilled (FZ- FiltekTM Z350 XT, 3M ESPE) and a microhybrid (ED-Empress® Direct, Ivoclar Vivadent) composites were photo-activated with two LCU: Valo® Cordless, Ultradent (VA-1800 mW/cm2 ) or Radii-cal, SDI (RA-900 mW/cm2 ). Samples (n = 5) were immersed during 12 days in distilled water (WT), orange juice (OJ), red wine (RW), coffee (CF), or Brazilian tea (BT). CIELAB coordinates were obtained using a spectrophotometer (Easyshade 4.0, Vita Zahnfabrik) before (T0 ) and after (T1 ) immersion. CIEDE2000 color difference (ΔE00 ) and whiteness index for dentistry (WID ) were calculated. Data was analyzed by two-way ANOVA and Tukey's test (α = 0.05%). FZ light-activated by VA showed higher L* and WID values (T0 ) and lower ΔE00 values after immersion in WT, OJ, and RW. However, there was no effect of both factors on ΔE00 when samples were immersed in BT and CF. ED light-activated by RA showed significant higher C* values (p ≤ .05). The nanofilled composite photo-activated with higher irradiance showed greater L* and WID values and better color stability. However, all samples immersed in colored beverages showed ΔE00 values above the acceptability threshold. Initial color of resin-based composites can change after immersion in staining beverages. However, the best color stability was obtained by the nanocomposite photo-activated by a light-curing unit of higher irradiance.

Effect of surface protection, staining beverages and aging on the color stability and hardness of recently introduced uncoated glass ionomer restorative material

AimEvaluation of the effect of coating, staining beverages and aging on the color stability and hardness of recently introduced glass ionomer (GI) restorative material and to determine whether there was a correlation between these two variables. Materials and methodsTwo commercially available conventional GI restorative materials were used; Ketac™ Universal Aplicap™ and Ketac™ Fil Plus Aplicap™ GI restoratives. A total of 84 disc-shaped specimens (5 × 2 mm) were prepared and divided into 3 main groups (n = 28). Fifty six specimens were prepared from Ketac Universal Aplicap where half of them was coated (CU) and the other half was uncoated (U) and 28 coated specimens from Fil Plus Aplicap™ (CF) that act as a control group. Coating was performed with Ketac Glaze. Each group was further subdivided into 4 subgroups (n = 7) according to the beverages (tea, coffee, coke and distilled water). Color changes (ΔE) and hardness (MPa) were measured by scanning spectrophotometer and Vickers's hardness (VH) test respectively. Measurements were recorded at the baseline, after 7 and 30 days of aging in each beverage. Chemical analysis of the glass powders was performed by EDXA. Additionally, the filler size was examined by the SEM. The data were statistically analyzed (P ≤ 0.05). ResultsThe CU subgroups possessed lower ΔE than U subgroups in tea and coffee. The impact of staining beverages and aging on the ΔE was material's dependent. The CU subgroups recorded higher VH than the U and CF subgroups after aging in coke (30 days). Aging of the U subgroups in tea and coke significantly decreased its VH. The SEM revealed smaller average filler size in Ketac Universal Aplicap (7.2 μm) than Ketac Fil Plus Aplicap (17.9 μm). Clinical significanceIt is advisable to use the recently introduced uncoated GI restorative material for patients who are not consuming tea and/or coffee but with surface protection to maintain its color acceptability up to 3 year clinically. Not all color changes could be associated with surface degradation.

Effect of staining beverages on color and translucency of CAD/CAM composites.

Direct, indirect, and CAD/CAM composites are all susceptible to various degrees of discoloration and translucency changes after exposure to staining beverages. Red wine generally caused the most discoloration and translucency changes. Although CAD/CAM composites were more color stable than direct and indirect materials when exposed to red wine, color changes were still clinically perceptible.

Discoloration of different esthetic restorative materials: A spectrophotometric evaluation.

Objective:A crucial property of esthetic restorative materials is their long-term color stability. The aim of this in vitro study was to evaluate the color stability of esthetic restorative materials (one microfilled flowable composite, one nanofilled composite, one nanoybrid composite, one microfilled composite, and one nanoybrid ormocer-based composite) after surface roughening with cola and exposure to different staining solutions (coffee and red wine).Materials and Methods:All materials were polymerized into silicone rubber rings (2 mm × 6 mm × 8 mm) to obtain 150 specimens identical in size. Seventy-five specimens of Group A were first exposed to cola for 24 h, and then samples were immersed in coffee or red wine over a 28-day test period. A colorimetric evaluation, according to the CIE L*a*b* system, was performed at 7, 14, 21, 28 days. Shapiro–Wilk test and Kruskal–Wallis analysis of variance were applied to assess significant differences among restorative materials. Means were compared with Scheffe's multiple comparison test at the 0.05 level of significance.Results:Specimens of Group A showed higher variations when compared with Group B's specimens (P < 0.05). After 28 days, the immersion protocols caused a clinically perceivable color change for all materials tested (P < 0.05). CeramX Universal and Admira Fusion showed the lowest ΔE variations (P < 0.05).Conclusions:Staining beverages caused significant discolorations for all the materials tested. The first exposure to cola enhanced the subsequent staining with coffee or red wine. Nanohybrid composites reported the lowest color variations.

Staining Beverages and Cigarette Smoke on Composite Resin and Human Tooth Fluorescence by Direct Spectrometry.

This study evaluated the fluorescence intensity (FI) of different brands of composite resins (CRs) and compare those values with the FI of human tooth, under the action of cigarette smoke (CI), coffee (CA), and soft drink (CO), measured by direct spectrometry. A total of 30 specimens of each brand (Filtek Z350, Esthet-X, Amelogen, Durafill) were made. Others 30 tooth specimens (3 mm/diameter) were obtained from human molars using a trephine bur. The specimens were randomly divided into three groups (n = 10), according to substances: CI, CA, CO. The FI was directly measured using an optic fiber associated with a spectrometer and was measured at baseline and after staining. Data were submitted to Kruskal-Wallis, Dunnett, and Dunn tests. Staining influenced FI mean values among CRs and between those with human tooth. Z showed the closest FI mean values of tooth after staining. Staining beverages and cigarette smoke negatively influenced on FI of CR and human tooth. The study shows darkening treatments influenced on the fluorescent property of the dental tissues and restorative materials according to the direct spectrometry analysis.

Color recovery effect of different bleaching systems on a discolored composite resin

Discoloration of resin-based composites is a commonly encountered problem, and bleaching agents may be used for the therapy of the existing discoloration. The purpose of this study was to investigate in vitro color recovery effect of different bleaching systems on the heavily discolored composite resin. Fifty disk-shaped dental composite specimens were prepared using A2 shade nanohybrid universal composite resin (3M ESPE Filtek Z550, St. Paul, MN, USA). Composite samples were immersed in coffee and turnip juice for 1 week in each. One laser activated bleaching (LB) (Biolase Laserwhite*20) and three conventional bleaching systems (Ultradent Opalescence Boost 40% (OB), Ultradent Opalescence PF 15% home bleaching (HB), Crest 3D White [Whitening Mouthwash]) were tested in this study. Distilled water was used as control group. The color of the samples were measured using a spectrophotometer (VITA Easy shade Compact, VITA Zahnfabrik, Bad Säckingen, Germany). Color changes (ΔE00) were calculated using the CIEDE2000 formula. Statistical analyses were conducted using paired samples test, one-way analysis of variance, and Tukey's multiple comparison tests (α = 0.05). The staining beverages caused perceptible discoloration (ΔE00 > 2.25). The color recovery effect of all bleaching systems was statistically determined to be more effective than the control group (P < 0.05). Although OB group was found as the most effective bleaching system, there was no statistically significant difference among HB, OB, and LB groups (P > 0.05). Within the limitation of this in vitro study, the highest recovery effect was determined in office bleaching system among all bleaching systems. However, home and laser bleaching systems were determined as effective as office bleaching system.

An In Situ Study of the Influence of Staining Beverages on Color Alteration of Bleached Teeth.

The aim of this study was to evaluate overall color change in bovine tooth fragments submitted to dental bleaching treatment performed simultaneously with the ingestion of beverages containing dyes. For this purpose, tooth fragments assembled into intraoral devices were submitted to at-home dental bleaching using 10% carbamide peroxide (CP) for 14 days and to immersion in staining beverages for 10 minutes daily. The specimens were divided into the following study groups according to bleaching treatment and staining substance (n=12): G I (negative control): no bleaching + distilled water; G II (positive control): bleaching + distilled water; G III: bleaching + coffee; and G IV: bleaching + grape juice. Twelve volunteers used the device continually, except during meals, oral hygiene, dental bleaching, and pigment challenge. Color readings were performed using a spectrophotometer both before the bleaching treatment and after each treatment week. The results were submitted to the normality test. The data obtained were submitted to analysis of variance and the Tukey or Kruskal-Wallis and Dunn tests (α=0.05). All bleached groups showed similar ΔE results at the end of treatment. Staining beverages generated negative ΔL mean values, and the lowest result was obtained in the treatment with coffee after 14 days. The Δa values in the groups that received treatment with staining beverages were higher when compared to the control groups. Dental bleaching associated with the consumption of staining substances may not affect overall tooth color change by the end of the treatment, although the consumption of staining substances did influence the different color dimensions.

The Color Stability of Resin Composite After Exposure to pH Solutions and Immerse Into Staining Beverages

본 연구는 3가지 다른 pH 용액에 노출된 후 착색 음료에 침전된 복합 레진의 색 변화를 평가하였다. 실험을 위해 A3색을 가진 복합레진 Z350 XT(3M ESPE, St. Paul, MN, USA)으로 직경 8 ㎜, 두께 2 ㎜의 시편을 제작하였다. 각 10개의 시편으로 서로 다른 3가지 pH용액(pH 3, pH 6, pH 9)에 14일 동안 노출 후 시편들을 다시 3그룹의 착색음료(증류수, 커피, 포도주스)에 3일 동안 침전시켰다. 착색음료 침전 전과 후의 L * , a * , b * 값을 spectrophotometer로 측정하고 측정값으로 색 변화와 투명도의 변화를 계산하였다. 계산된 결과값을 ANOVA와 Tukey’s test로 분석하여 다음과 같은 결과를 얻었다. 실험 결과, 색 변화(ΔE) 값은 착색음료 종류에 따른 통계학적 유의한 차이는 있었으나(p ＜ 0.05), 이전의 노출된 pH 용액에 따른 유의한 차이는 없었다(p ＞ 0.05). 착색 음료 침전 후 반투명도 지수(TP) 값은 증류수를 제외하고 감소되는 경향이었고, 반투명도 지수 변화(ΔTP)는 포도주스에서 가장 높았다. 결론적으로 복합 레진의 색 안정성은 기존의 다양한 pH 용액에 노출된 상태가 아니라 착색 음료에 의존하는 것으로 사료된다.

Effect of potentially chromogenic beverages on shear bond strength of acrylic denture teeth to heat-polymerized denture base resins.

Background:Detachment of denture acrylic resin artificial teeth from denture base resin is one of the most common problems presented by denture wearers. Purpose: This study investigated the shear bond strength (SBS) and fracture type of bonding interface of two commercial acrylic teeth (Vipi Dent Plus e Biolux) to two denture base resins (Vipi Cril e Lucitone 550) after immersion in potentially chromogenic beverages (coffee, cola soft drink, and red wine) or control solution (distilled water).Materials and Methods:Maxillary central incisor acrylic teeth were placed at 45° to denture base resin and submitted to short polymerization cycle according to manufacturers. Specimens were divided according to the combination tooth/resin/solution (n = 8) and submitted to bond strength tests in a universal testing machine MTS-810 (0.5 mm/min). Subsequently, fracture area was analyzed by stereomicroscope at a magnification of ×10 and categorized into adhesive, cohesive, or mixed failure.Results:The bond strength of teeth/denture base resins interface was not significantly affected by tested solutions (P > 0.087), except for Biolux teeth immersed in coffee (P < 0.01). In all conditions, the Vipi Dent Plus teeth showed higher bond strength to Lucitone and Vipi Cril resins when compared to Biolux teeth (P < 0.003). All specimens’ failure modes were cohesive.Conclusions:The SBS of acrylic teeth to denture base resins was not generally influenced by immersion in the tested staining beverages.

Surface properties of multilayered, acrylic resin artificial teeth after immersion in staining beverages.

Objective To evaluate the effect of staining beverages (coffee, orange juice, and red wine) on the Vickers hardness and surface roughness of the base (BL) and enamel (EL) layers of improved artificial teeth (Vivodent and Trilux).Material and Methods Specimens (n=8) were stored in distilled water at 37°C for 24 h and then submitted to the tests. Afterwards, specimens were immersed in one of the staining solutions or distilled water (control) at 37°C, and the tests were also performed after 15 and 30 days of immersion. Data were analyzed using 3-way ANOVA and Tukey’s test (α=0.05).Results Vivodent teeth exhibited a continuous decrease (p<0.0005) in hardness of both layers for up to 30 days of immersion in all solutions. For Trilux teeth, similar results were found for the EL (p<0.004), and the BL showed a decrease in hardness after 15 days of immersion (p<0.01). At the end of 30 days, this reduction was not observed for coffee and water (p>0.15), but red wine and orange juice continuously reduced hardness values (p<0.0004). Red wine caused the most significant hardness changes, followed by orange juice, coffee, and water (p<0.006). No significant differences in roughness were observed for both layers of the teeth during the immersion period, despite the beverage (p>0.06).Conclusions Hardness of the two brands of acrylic teeth was reduced by all staining beverages, mainly for red wine. Roughness of both layers of the teeth was not affected by long-term immersion in the beverages.

Preheating impact on the colour change of pit-and-fissure sealants after immersion in staining beverages

BackgroundThe development of techniques improving the colour stability on restorative materials has become of great importance due to pigmentation as an important factor that induces colour changes. This study aimed to evaluate the influence of the preheating of resin-based pit-and-fissure sealants on colour stability when in contact with staining beverages. MethodsThe Fluroshield (Dentsply, USA) sealant was used in white and clear shades. One hundred and twenty specimens were light-cured at different temperatures (25°C and 68°C) and immersed in distilled water (37°C) for 24h (T0). Thereafter, the specimens were submerged in different solutions, such as cola soft drinks, distilled water or grape juice (n=10), for 7 days (T1) (37°C). The colour was measured by a digital spectrophotometer (Easy Shade, Vita Zahnfabrik) right after T0 and T1 following the CIE-L*a*b* parameter. Results were obtained after calculating the colour change after T1 (ΔE) and analysed through 3-way ANOVA test and Tukey post hoc test (p<0.05). ResultsPreheating resulted in decreased colour change in both materials. The white Fluroshield sealant showed lower ΔE values and grape juice promoted the highest colour change. ConclusionThe preheating was effective to improve colour stability of resin-based pit-and-fissure sealants when in contact with grape juice and cola drink.

In vitro assessment of color changes of clear orthodontic elastomeric module materials after exposure to high-pigment beverages

BackgroundAesthetic elastomeric modules are subject to staining as a result of exposure to foods and beverages that can cause staining. The objective of this study was to assess, in vitro, color changes of clear orthodontic elastomeric module materials exposed to different staining beverages. MethodsSamples of four brands of clear orthodontic elastomeric modules (Morelli, TP Orthodontics, RMO, and GAC) were immersed for 15 minutes, three times weekly, in four beverages that can cause staining: coffee, cola, black tea, and red wine. Between sessions, samples were stored in artificial saliva at 37°C. Color changes were assessed after 4 weeks using the yellowness index (YI) (ASTM International D-6290/E-313-10 standard practices), calculated according to the Comission Internationale de l'Eclairage L*a*b* system with the aid of a spectrophotometer (range 0 to 100, with higher values indicating more yellowness). YI results were analyzed using ANOVA and the Tukey multiple comparisons test. ResultsDifferent degrees of discoloration were observed across the brands, despite the similarity of chemical structures. Coffee caused the most severe color change (mean ± SD YI 56.1 ± 0.79), followed by red wine (38.0 ± 0.78) and black tea (31.9 ± 0.63); these differences were significant. The GAC modules were the least affected by yellowness, whereas Morelli showed the highest degree of discoloration. Conclusion(s)The intake of foods and beverages with a high pigment content can cause discoloration of clear orthodontic elastomeric modules and thus lead to aesthetic complaints. Our findings can help practitioners select the most appropriate brand of elastomeric modules according to the dietary habits of each patient.

The translucent and color change of nanofilled composite resin according to resin shades and staining solutions

This study examined the color changes in a resin composite with different shades after exposure to different drink media. A nanohybrid resin composite (Filtek Z350 XT) was exposed to a pH 6 solution for 2 weeks and then immersed in a staining solution (Coffee or Grape juice) or distilled water (as control) for 3 days. The color coordinates of the specimen before and after immersion in the staining solutions were measured using a spectrophotometer. The color difference (ΔE ) and the change in the translucency parameter (ΔTP ) were calculated using the CIEL*a*b* system. The data was statistically analyzed using ANOVA and a Tukey’s test. The ΔE of the specimens tested differed significantly according to the staining solutions (p<0.05) and the shades of the composite resins (p<0.05). Coffee and B1 shade showed the greatest color change. The values of TP after immersion in the staining beverages decreased except for distilled water. The absolute ΔTP values of grape juice were higher than the others regardless of the shades. Overall, the color stability of the resin composites differs according to the staining media used and shade of the composite resins.

Cytotoxicity of dental light-cured calcium hydroxide cements on human dental pulp stem cell

This study examined the color changes in a resin composite with different shades after exposure to different drink media. A nanohybrid resin composite (Filtek Z350 XT) was exposed to a pH 6 solution for 2 weeks and then immersed in a staining solution (Coffee or Grape juice) or distilled water (as control) for 3 days. The color coordinates of the specimen before and after immersion in the staining solutions were measured using a spectrophotometer. The color difference (ΔE ) and the change in the translucency parameter (ΔTP ) were calculated using the CIEL*a*b* system. The data was statistically analyzed using ANOVA and a Tukey’s test. The ΔE of the specimens tested differed significantly according to the staining solutions (p<0.05) and the shades of the composite resins (p<0.05). Coffee and B1 shade showed the greatest color change. The values of TP after immersion in the staining beverages decreased except for distilled water. The absolute ΔTP values of grape juice were higher than the others regardless of the shades. Overall, the color stability of the resin composites differs according to the staining media used and shade of the composite resins.

Influence of Different Staining Beverages on Color Stability, Surface Roughness and Microhardness of Silorane and Methacrylate-based Composite Resins

To investigate the influence of different staining beverages on color stability, surface roughness and microhardness of silorane and methacrylate-based composite resins. Three different composite resins (Filtek Silorane, Filtek P60, Filtek Supreme XT) were tested. Thirty cylindrical specimens (10 × 2 mm) per material were prepared and polished with a series of aluminum-oxide polishing disks. Each group was then randomly subdivided into three groups according to the test beverages: distilled water (control), cola and coffee. The samples were immersed into different beverages for 15 days. Color, surface roughness and microhardness values were measured by a spectrophotometer, prophylometer and Vickers hardness device respectively, at baseline and after 15 days. The data were subjected to statistical analysis. Immersion in coffee resulted in a significant discoloration for all the composites tested, although the color change was lower in Filtek Silorane than that of MBCs (p < 0.05). All the composites tested showed similar surface roughness changes after immersion in different beverages (p > 0.05). Besides coffee caused more roughness change than others. Immersion in coffee caused highest microhardness change in Filtek Supreme XT (p < 0.05). Cola and coffee altered, to some degree, the color, surface roughness and/or microhardness of the tested resin composites, depending on the characteristics of the materials.

Color Stability of Restorative Materials in Response to Arabic Coffee, Turkish Coffee and Nescafe

To evaluate the effect of Arabic coffee, Turkish coffee and Nescafe on the color stability of four different composite resins after a period of aging time 1, 7 and 30 days. Twenty specimens from each type of tested composite resin material were prepared. Five specimens from each tested material (Z350 XT, Artist, GC and Z250) was evaluated after storage in Arabic coffee, Turkish coffee, Nescafe and distil water (control) at 37°C in a dark container for 1, 7 and 30 days. Color measurement was done using colorimeter based on the CIE L* a* b* color scale. Color differences ΔE*ab, Δb* and Δa* among specimens immersed in distil water and staining coffee beverages were evaluated overtime. Mean values were statistically analyzed with one-way analysis of variance (ANOVA), followed by Tukey test with p < 0.05 as significance level. All tested composite resins showed increase color change after a period of 1, 7 and 30 days. The color change ΔE*ab , Δb* and Δa* exhibited by Arabic coffee, in Turkish coffee and Nescafe except Δa*. The highest total color difference ΔE*ab after 30 days was in group A Arabic coffee (ΔE > 1.5 perceivable) and not perceivable in group B Turkish coffee and group C Nescafe. For Δb* all materials discolored toward yellowness after 30 days except Arabic coffee group which shifted from yellowness toward blueness (Δb*> 1.5 perceivable). The effect of staining beverages on the resin composite materials increases with time of aging toward yellowness and not perceivable in all groups except with Arabic coffee which had highest effect after 30 days and the discoloration shifted from yellowness to blueness perceivable.