Staining of Hybrid Composites with Coffee, Oolong Tea, or Red Wine

The color stability of artificial white spot lesions treated with resin infiltration after exposure to staining beverages

BACKGROUND

To evaluate the effect of staining beverages on the color-changing of resin-infiltrated artificial white spot lesions (WSLs).

METHODS

Thirty-five artificial WSLs were created by pH cycling on flat bovine teeth specimens. The WSLs were treated with resin infiltration and were divided into five groups based on staining beverages: artificial saliva, coffee, wine, green tea, and Coca-Cola. These specimens were subjected to a 28-day exposure to the respective beverages. Color stability was assessed using a spectrophotometer at different time points: baseline, after 7, 14, 21, and 28 days of exposure, and repolishing. The color difference (∆E) between each time point and the baseline was calculated. Statistical analysis was performed using two-way measures ANOVA with a significance level of p = 0.05.

RESULTS

All resin-infiltrated specimens exposed to staining beverages for 7 days exhibited more significant color changes than those exposed to artificial saliva. The color change patterns varied based on the type of beverage. The color alterations intensified with extended immersion in the wine and Coca-Cola groups, while there were no significant differences in the color of specimens after 28 days of immersion in the coffee and green tea groups. However, after cleaning with pumice powder, all specimens showed significantly reduced color changes compared to those observed after 28 days of immersion, except those immersed in coffee.

CONCLUSIONS

Exposure of resin-infiltrated bovine tooth specimens to staining beverages resulted in a significant color alteration as the immersion time increased. However, the staining effect could be minimized by cleaning with pumice powder, except for the coffee group.

CLINICAL RELEVANCE

After resin infiltration treatment, patients should be advised to minimize the consumption of colored beverages to prevent staining that could impact esthetic appearance.

Impact of common social habits on optical properties of lithium disilicate glass ceramic crowns: An in vitro study

Statement of the problem

Patient stratifications considered the stability of color and treatment longevity are key success of restoration. Daily consumption of colored beverages, such as coffee, tea, and soft drinks, as well as the use of globally consumed materials, such as smokeless tobacco (ST), snuff, Khat, and Yerba mate, can change the color of restorative materials, such as lithium disilicate glass ceramics (LDGC). These changes can ultimately lead to treatment failure.

Purpose

This in vitro study aimed to evaluate color changes, translucency, and opalescence of full anatomical LDGC crowns exposed to commonly used and potentially colorant solutions.

Materials and methods

Ninety LDGC specimens/crowns were prepared and divided into nine groups according to immersion solution (control, Saudi Coffee, Cola, Khat, Yerba mate, Nescafe, ST Snuff, and Mixed Fruit Juice). The specimens were immersed in colorant solutions for 15 days with alternating twice daily at 37 °C. Color parameters were measured with a spectrophotometer and calculated using two backgrounds (black and white). Data were subjected to ANOVA followed by the Student t-test and Bonferroni test at a significant difference level (α = 0.05).

Results

The greatest color change (ΔE*) among groups after immersion was observed in Yerba mate (7.6 ± 1.6). The mean difference of before and after staining within Yerba mate group was 3.14 ± 1.6 (p = 0.001). Translucency mean values of groups after immersion into staining media were ranging between 7.6 ± 1.2 and 9.1 ± 2, showing a slight decrease compared with pre-staining values but was not significantly different. Immersion in Mixed Fruit Juice significantly reduced opalescence (7.4 ± 1.9) compared to (8.8 ± 1.7) before staining.

Conclusion

The findings confirm that appropriate user guidance helps to preserve both translucency and opalescence as well as prevent color changes. This can improve patient compliance and promote treatment longevity.

In Vitro Model to Evaluate the Development of Discolorations on Human Enamel Caused by Treatment with Mouth Rinses and Black Tea Considering Brushing

OBJECTIVES

 The study aimed to develop and test an in vitro model to investigate the staining potential of mouth rinses on human enamel, considering alternating intake of black tea and tooth brushing, thus mimicking the situation in the oral cavity more realistically.

MATERIALS AND METHODS

 Eight mouth rinses with six different active ingredients (benzydamine hydrochloride [BNZ], polyhexamethylene biguanide hydrochloride [PHMB], chlorhexidine digluconate [CHX], hexetidine gluconate [HEX], octenidine dihydrochloride [OCT] and octenidine dihydrochloride + 2-phenoxyethanol [OCTP]) and concentrations were tested. Sets of six halved human molar crowns were initially pretreated by soaking in artificial saliva (30 min). Afterward, the cyclic treatment was started by soaking in artificial saliva (2 min), staining with black tea (1 min), brushing with toothpaste (5 s), and soaking in the mouth rinse (30 s). Samples were rinsed with distilled water after each treatment step. The cyclic treatment was repeated 30 times, mimicking the consumer behavior after 15 days. Photographic images were taken after 0, 10, 20, and 30 cycles. Color measurements were conducted after each staining and brushing step using a VITA-Easyshade spectrophotometer to determine the difference in lightness ∆L and the total color difference ∆E.

STATISTICAL ANALYSIS

 Analysis of variance and post-hoc Tukey test (α = 0.05) were applied.

RESULTS

 The new testing model with included brushing sequences allowed to assess the staining behavior on human teeth and provided a clear differentiation between the different investigated products. In detail, up to cycle 10, ΔE values increased for all mouth rinses with each additional cycle number. However, while ΔE values continued to increase for 0.15% BNZ, 0.1% PHMB, and 0.2% CHX between treatment cycle 10 and 30, ΔE values only slightly increased after treatment with 0.08% OCTP, 0.1% OCTP, 0.1% OCT, and 0.1% HEX. After 20 and 30 cycles, significantly less staining was found for 0.08% OCTP, 0.1% OCT, 0.1% HEX as compared to 0.2% CHX, 0.15% BNZ, and 0.1% PHMB (p < 0.05). ΔE-values were significantly lower after treatment with 0.1% OCTP as compared to 0.2% CHX1 and 0.2% CHX2 (p < 0.05).

CONCLUSION

 The proposed new methodology was found to be appropriate for assessing the staining progression of mouth rinses over a simulated application period of 15 days. The model allows differentiation of products with different active ingredients and concentrations.

Effect of surface roughness and biofilm formation on the color properties of resin-infiltrated ceramic and lithium disilicate glass-ceramic CAD-CAM materials

STATEMENT OF PROBLEM

Computer-aided design and computer-aided manufacturing (CAD-CAM) materials have become popular for dental restorations; however, which materials should be preferred in terms of surface properties after biofilm formation is unclear.

PURPOSE

The purpose of this in vitro study was to investigate the effect of biofilm formation on the discoloration properties of resin-infiltrated ceramic and glass-ceramic CAD-CAM materials and human teeth and to examine the effect of the brushing procedure on color change.

MATERIAL AND METHODS

One hundred and six 2-mm-thick specimens were prepared from IPS e.max CAD and Cerasmart, and a total of 53 intact human teeth were used. Five specimens from each group were used to measure the amount of live biomass in the biofilm. The remaining 48 specimens in each group were divided into 4 subgroups: kept in distilled water without the formation of dental biofilm (DW), kept in tea without the formation of dental biofilm (T), kept in distilled water after the formation of dental biofilm (DWB), and kept in tea after the formation of dental biofilm (TB) (n=12). After finishing and polishing the materials, initial color measurements were made using a spectrophotometer, and surface roughness measurements were made using noncontact profilometer. After creating a biofilm layer in DWB and TB, all specimens were kept in their solutions at 37 °C for 24 hours, and the color measurements were repeated. After the biofilm layer had been removed by brushing, a third color measurement was made. The data were statistically analyzed with one-way analysis of variance (ANOVA) and two-way ANOVA (α=.05).

RESULTS

The lowest roughness value was observed in Cerasmart. Tooth-IPS e.max CAD gave similar results. The Cerasmart material had the most viable biomass, whereas the IPS e.max CAD material had the least. TB had the highest ΔE1 value for all materials and DW had the lowest (P<.05). The brushing procedure caused the materials to return to their initial colors or reduce the color change in most groups.

CONCLUSIONS

The presence of biofilm on CAD-CAM materials immersed in distilled water caused an unacceptable degree of discoloration (ΔE>1.8), and immersion in tea led to greater color change. The adhesion of biofilm to restorative dental materials plays an important role in the coloring of these dental materials.

Effects of various beverages on characteristics of provisional restoration materials

OBJECTIVE

To investigate the effect of common beverages on four currently used provisional restoration materials: Protemp®4, Integrity®, polymethyl methacrylate (PMMA) block, and acrylic resin. Flowable resin composite is included as a control group.

MATERIALS AND METHODS

Each material was formed into disks of 10-mm diameter and 4-mm thickness (N = 40) by loading the material into acrylic molds. The exposed surface in the mold was covered using a glass slide to prevent an oxygen inhibition layer, and polymerization then proceeded. The solidified disks were placed in distilled water for 24 h. These samples (n = 8) were then immersed for 14 days in one of four different beverages: water, orange juice, cola, and coffee. Changes in color dimension, hardness, and roughness were observed and then analyzed using two-way repeated analysis of variance.

RESULTS

The provisional materials had more obvious changes in all three color dimensions than the flowable resin composite. Integrity showed the biggest changes, followed by acrylic resin and PMMA block, whereas Protemp had the smallest changes. The hardness of all the materials significantly decreased after immersion in any of the beverages for 14 days. There were no changes in surface roughness when the materials were immersed in distilled water. The surface roughness of the PMMA block significantly decreased in orange juice whereas that of Integrity and acrylic resin significantly increased in cola.

CONCLUSION

Different kinds of provisional materials had different degrees of staining due to their composition. Moisture had a significant influence on the hardness of materials, and the acidity of cola significantly roughened the surface of the provisional materials.

Effects of two novel denture cleansers on multispecies microbial biofilms, stain removal and the denture surface: an in vitro study

BACKGROUND

The continuously increasing demand for removable denture appliances and the importance of adequate denture cleaning have led to the development of various denture cleansing products. The aim of this study was to evaluate the efficacy of two novel denture cleansing agents (GE and TM) and three commonly available cleansers (0.5% sodium hypochlorite; NaClO, 0.12% chlorhexidine gluconate; CHX, and Polident®; POL) on multispecies microbial biofilm formation, stain removal and physical properties of dentures.

METHODS

The antimicrobial activities of denture cleansing agents were determined against major oral opportunistic pathogens including Streptococcus mutans, Staphylococcus aureus, Escherichia coli and Candida albicans, using time-kill assays. Multispecies microbial biofilms grown on acrylic resins for 72 h were generated to determine the antibiofilm effects of cleansing agents by confocal laser scanning microscopy (CLSM). Evaluations of the tea and coffee stain removal properties and the alterations in the physical properties of dentures were also performed. The toxicity of cleanser residues released from denture acrylics to fibroblast cells was investigated using MTT assay.

RESULTS

All denture cleansing agents tested could effectively kill oral bacteria and Candida albicans. Furthermore, after immersion for more than 3 h, the cleansers Polident®, GE and TM could efficiently penetrate and inhibit multispecies denture biofilms with effects similar to 10 min of immersion in 0.5% NaClO. However, immersion in 0.12% CHX for 20 min showed less antibiofilm activity. The NaClO solution had the highest efficacy for removing stains from the artificial teeth. Conversely, the CHX solution enhanced tea and coffee staining, and the teeth immersed in this solution showed clinically unacceptable colour changes (ΔE > 5.5). However, the colour differences of teeth stained and immersed in POL, GE and TM cleansers were in the clinically acceptable range. There was no significant difference among the POL, GE and TM cleansers in terms of stain removal efficacy. The cleansers GE and TM did not alter the surface roughness and colour of the materials, moreover the residues of both cleansers did not exhibit cytotoxicity.

CONCLUSION

Two novel denture cleansing agents containing natural products, GE and TM exhibited effective antimicrobial activity, antibiofilm and stain removal capabilities without toxicity or disturbance of the physical properties of acrylics.

Coffee pulp: From a by-product of coffee production to a potential anticariogenic mouth rinse! An in vivo study

Background and Objectives

Dental caries is a prevalent disease despite various efforts made toward its prevention. The drawbacks of the available preventive agents have led to the quest for a potentially more effective agent with fewer adverse effects. Coffee, a local produce of Coorg, is one such herbal alternative. This study aims to assess the potential antimicrobial activity of Robusta coffee pulp extracts on Streptococcus mutans.

Methodology

A total of 39 participants were divided into three groups with 13 participants each, after obtaining ethical clearance and informed consent: Group A (negative control), sterile water; Group B (positive control), 0.2% chlorhexidine mouth rinse; and Group C, 2.5% coffee pulp extract rinse (prepared according to minimum inhibitory concentration). The saliva samples were collected from the patients in a sterile Eppendorf tube at prerinse for baseline, at 1-h postrinse, and at the end of 2 weeks. The S. mutans colony count was done using image-based software analysis. The acquired data were statistically analyzed with one-way ANOVA and repeated measures ANOVA followed by post hoc Tukey's test.

Results

Coffee pulp mouth rinse (P = 0.035) and positive control (P = 0.036) groups showed a statistically significant reduction in the microbial count at 2 weeks postrinse (compared to the negative control group).

Conclusion and Clinical Relevance

The coffee pulp extract-based mouth rinse is a potential anticariogenic agent that offers few advantages over chlorhexidine as no instances of staining, altered taste, or any allergic reactions were reported by the subjects.

Evaluation of the effects of whitening toothpaste containing nanohydroxyapatite on surface roughness and color change in restorative materials

Background

The effects of whitening toothpastes containing nanohydroxyapatite on the surfaces of restorative materials are not well known. This study evaluated the changes in surface roughness and color of coffee-stained restorative materials after brushing with nanohydroxyapatite and other whitening toothpastes.

Methods

Disc-shaped specimens were formed using microhybrid, nanohybrid, and supra-nano-filled composite (n = 30) and stained with a coffee solution. A brushing simulation was applied with toothpastes containing nanohydroxyapatite (Dentiste Plus White), perlite (Signal White System) and hydrogen peroxide (Colgate Optic White) for 7, 15, and 30 days. Color and surface roughness measurements were taken before and after brushing. Color change (∆E₀₀) was calculated using the CIEDE2000 system.

Results

Supra-nano-filled composite-Dentiste Plus White, supra-nano-filled composite-Colgate Optic White, and nanohybrid composite-Signal White System were the groups with the greatest color change observed on the 7th, 15th, and 30th days, respectively. The smallest color change was seen in the microhybrid composite-Signal White System, microhybrid composite-Dentiste Plus White, and nanohybrid composite-Dentiste Plus White groups on the 7th, 15th, and 30th days, respectively. No significant surface roughness changes were observed in the nanohybrid composite-Dentiste Plus White, supra-nano-filled composite-Colgate Optic White, supra-nano-filled composite-Dentiste Plus White, or supra-nano-filled composite-Signal White System groups.

Conclusions

Whitening toothpaste containing nanohydroxyapatite provided a high degree of color change in the short term and did not create significant surface roughness in nanohybrid or supra-nano-filled composites.

Chemical and Structural Assessment of New Dental Composites with Graphene Exposed to Staining Agents

Among the newest trends in dental composites is the use of graphene oxide (GO) nanoparticles to assure better cohesion of the composite and superior properties. Our research used GO to enhance several hydroxyapatite (HA) nanofiller distribution and cohesion in three experimental composites CC, GS, GZ exposed to coffee and red wine staining environments. The presence of silane A-174 on the filler surface was evidenced by FT-IR spectroscopy. Experimental composites were characterized through color stability after 30 days of staining in red wine and coffee, sorption and solubility in distilled water and artificial saliva. Surface properties were measured by optical profilometry and scanning electron microscopy, respectively, and antibacterial properties wer e assessed against Staphylococcus aureus and Escherichia coli. A colour stability test revealed the best results for GS, followed by GZ, with less stability for CC. Topographical and morphological aspects revealed a synergism between GZ sample nanofiller components that conducted to the lower surface roughness, with less in the GS sample. However, surface roughness variation due to the stain was affected less than colour stability at the macroscopic level. Antibacterial testing revealed good effect against Staphylococcus aureus and a moderate effect against Escherichia coli.

Hardness and surface roughness of differently processed denture base acrylic resins after immersion in simulated gastric acid

STATEMENT OF PROBLEM

The effect of gastric acid on the surface properties of denture base acrylic resin is unknown.

PURPOSE

The purpose of this in vitro study was to evaluate changes in the surface roughness and hardness of denture base acrylic resins after immersion in simulated gastric acid.

MATERIAL AND METHODS

Acrylic resin specimens (n=10) were prepared with 3 different processing techniques (compression-molded, injection-molded, and computer-aided design and computer-aided manufacturing [CAD-CAM] milled) and exposed to either gastric acid or artificial saliva (control). Surface roughness and hardness were measured at baseline (T0) and after 24-hour (T24) and 96-hour (T96) immersion in the solutions. The surface roughness and hardness data were analyzed by 3-way ANOVA and the Tukey HSD test (α=.05).

RESULTS

At T24, the greatest change in surface hardness was observed for compression-molded specimens in gastric acid (P<.05). At T96, changes in hardness values were higher in compression-molded specimens than those in milled specimens (P<.05). Regarding surface roughness, at T24, compression-molded and injection-molded specimens showed higher values than milled specimens in gastric acid (P<.05). Concerning specimens in artificial saliva, compression-molded specimens showed significantly higher changes in roughness than those of the others (P<.05). At T96, injection-molded specimens had the greatest roughness values (P<.05). Among specimens immersed in artificial saliva, milled specimens showed lower roughness values than the injection-molded or compression-molded specimens (P<.05).

CONCLUSIONS

Gastric acid exposure adversely affected the roughness and hardness of all the acrylic resins evaluated. CAD-CAM milled specimens showed better resistance to acid exposure after 24 and 96 hours in terms of roughness and hardness.

Evaluation of the Color Stability, Water Sorption, and Solubility of Current Resin Composites

This study aims to assess the color stability, water sorption, and solubility of 11 resin composites as commercially available dental products. Twenty samples (10 mm in diameter and 2 mm in thickness) of each material were fabricated using a customized silicone mold, followed by immersion in each of curry, coffee, wine, and distilled water for 28 days (n = 5). Baseline shade and color changes (ΔE) were measured using a reflection spectrophotometer. The CIE L*, a*, b* system was used to evaluate the color changes. Five samples of each resin composite were applied to test water sorption and solubility according to ISO 4049:2009. As a result, the ∆E values were significantly influenced by each of the three factors (composition of material, solution, time) and the interactions between them (p < 0.001). Highest resistance to discoloration was achieved by Ceram.X One Universal (CXU), followed by Magnafill Putty (MP). Generally, microhybrid composites showed fewer color changes than nanohybrid composites and giomers. DX. Universal and Filtek Z350 XT showed the highest ΔE values in all colorants. All materials tested in this study fulfilled the criteria of ISO 4049:2009; CXU and MP had the lowest water sorption and solubility. The Pearson test showed statistically significant positive correlations between water sorption and ΔE and between solubility and ΔE.

Color changes of dental zirconia immersed in food and beverage containing water-soluble/lipid-soluble pigments

The present study examined color changes in the tooth-colored restorative materials, zirconia (3Y-TZP), resin composite, and porcelain. The colors (CIELab) of these materials were measured using a spectrophotometer. Specimens were immersed in black tea or curry for 1 and 7 days, after which colors were re-assessed. Color differences (∆E^*ab) before and after immersion were calculated. Specimens after the 7-day immersion were ultrasonically cleaned, and colors were measured again to assess the color recovery rate. The surface free energy, roughness, and water sorption/solubility of each material were also evaluated. Specimens were observed under a scanning electron microscope. The ∆E^*ab of 3Y-TZP was the smallest with both immersions. Resin composite had the smallest recovery rate. The surface free energy and roughness of 3Y-TZP were smaller than those of porcelain. 3Y-TZP and porcelain showed almost no sorption during the 7-day period. The present results revealed that 3Y-TZP exhibited the strongest resistance to discoloration.

Effects of Charcoal Toothpaste on the Surface Roughness, Color Stability, and Marginal Staining of Resin Composites

OBJECTIVE

This study was designed to evaluate the effects of charcoal toothpaste on the surface roughness, color stability, and marginal staining of resin composite restorations.

METHODS

A total of 100 bovine incisors was collected. The crowns were sectioned and randomly divided into 10 groups (n=10) according to two study factors: toothpaste groups and nanoparticle resin composite groups. Five toothpastes-Bianco Pro Clinical (Bianco Oral Care, Uberlândia, MG, Brazil) - Control group; Bianco Carbon (Bianco Oral Care); NAT, Natural Suavetex Carvão Ativado (Suavetex, Uberlândia, MG, Brazil); Nano Action Black Be Emotion (Polishop, Jundiaí, SP, Brazil); and BIW, Black is White (Curaprox, Curaden AG, Kriens, Switzerland)-and two resin composites-Z350XT, Filtek Z350XT (3M Oral Care) and Vittra, Vittra APS (FGM, Joinville, SC, Brazil)-were used. Circular cavities with a diameter of 4 mm and a depth of 1 mm were prepared on the buccal face of the tooth crowns and restored with resin composites. The specimens were subjected to three months of simulated toothbrushing. The surface roughness (right angle [Ra], in micrometers [μm]) of the resin composites was measured before and after toothbrushing in five areas per specimen. The resin composite color and luminosity changes (ΔE and ΔL, respectively) were measured using reflectance spectroscopy (Vita EasyShade). Macro photographs were taken before and after toothbrushing to qualitatively analyze the marginal staining (MSt) of the resin composite restorations. Scanning electron microscopy (SEM) was performed before and after the simulated toothbrushing. Ra data were analyzed using two-way analysis of variance with repeated measures and the Tukey HSD test; MSt was analyzed using Kruskal-Wallis and Dunn tests (α=0.05), and the resin composite color change was analyzed using the clinically unacceptable level of ΔE > 3.3.

RESULTS

Simulated brushing increased Ra irrespective of the resin composite or toothpaste used. No significant differences were found in Ra between the control group and all groups on which the charcoal toothpastes were tested. A clinically unacceptable level of resin composite color change (ΔE>3.3) was found after the use of most charcoal toothpastes. Use of Bianco Carbon resulted in marginal staining similar to that of the control group and was lower than that of the other charcoal toothpastes. Vittra brushed with black toothpaste showed the highest marginal staining.

CONCLUSION

Use of charcoal toothpaste resulted in Ra values of resin composites similar to those found with conventional toothpastes. Charcoal toothpaste generally resulted in clinical resin composite color changes (ΔE). All charcoal toothpastes, except Bianco Carbon, caused marginal staining of the resin composite restorations.

Effect of finishing protocols and staining solutions on color stability of dental resin composites

Objective

The objective of this study was to evaluate the effect of finishing protocol and exposure to staining solutions on color stability of dental resin composites.

Materials and Methods

A nanofill and microhybrid composite, three finishing protocols (mylar, Soflex disc, and white polishing stone) and four staining solutions (tea, red wine, khat extract—two concentrations, control—distilled water) were evaluated. A digital spectrophotometer was used for color change (ΔE) measurements employing the CIE‐Lab‐color system. Paired/independent‐sample t test and two‐way analysis of variance (ANOVA) followed by Tukey's honestly significant difference posthoc test were used for inferential statistics at α = .05.

Results

Soflex finish was associated with least staining and comparable color stability for the two materials in tea and red wine. In Khat 2, microhybrid composite had statistically significant better color stability than nanofill for Soflex finish (14 days t = 3.270, p = .011). For microhybrid composite, mylar resulted in highest mean ΔE, whereas Soflex recorded the least in all staining solutions. For nanofill composite, white stone resulted in highest mean ΔE, whereas Soflex demonstrated the least mean ΔE in all staining solutions, except red wine where mylar demonstrated the least mean ΔE. For mylar finish, nanofill demonstrated statistically significant better color stability than microhybrid in both red wine (14 days t = 4.902, p = .001) and Khat 1 (14 days t = 3.252, p = .012). For stone finish, microhybrid demonstrated statistically significant better color stability than nanofill in all staining solutions (14 days t ≥ 4.785, p ≤ .001). Two‐way ANOVA showed a statistically significant difference in mean ΔE between and within specimens (F = 42.658, p < .001). All staining solutions caused clinically unacceptable discoloration for mylar and white stone finish. For Soflex finish, red wine produced clinically unacceptable color difference beyond 48 h.

Conclusion

There was a difference in color stability of resin composites depending on filler type, further influenced by finishing protocol. Soflex disc finish results in better color stability than mylar and white stone in both microhybrid and nanofill composites.

Clinical significance

Esthetic dental restorations such as resin composites are routine in contemporary restorative practice. Color stability of composites may be influenced by surface finish, dependent on the filler type, and consumption of chromogenic substances such as khat. To prolong their service, selection of suitable finishing protocols is an important consideration.

The Impact on Dental Staining Caused by Beverages in Combination with Chlorhexidine Digluconate

OBJECTIVES

 There are several hypotheses regarding how chlorhexidine (CHX) digluconate causes staining with the role of beverages, specifically the precipitation of anionic dietary chromogens onto adsorbed cations, the most probable cause. The aim of this study was to investigate and compare the staining potential of common beverages using an in vitro staining and brushing model to better understand the interactions between chromogens from different beverage categories and the teeth.

MATERIALS AND METHODS

 Human enamel samples were exposed to a cyclic treatment of artificial saliva and 0.2% CHX mouthwash combined with a range of beverages, with and without brushing, simulating a period equivalent to 2 weeks. Eleven beverages were tested: diet coke, diet lemonade, white wine, red wine, lager beer, black tea, coffee, black tea with milk, coffee with milk, ginger and lemon infusion, and water. Toothbrushing was performed in a brushing simulator with toothpaste and also with water. Colorimetric differences were determined by ΔE using a VITA Easyshade dental spectrophotometer. Statistical analyses were performed by one-way analysis of variance with post hoc Tukey's honestly significant difference test and Levene's test.

RESULTS

 Black tea and red wine produced highest staining, which agrees with the literature. Significant staining was also observed for a ginger and lemon infusion, coffee, coffee with milk, tea with milk, and lager beer compared with water (p < 0.05). The staining potential of diet coke in combination with brushing appeared to be connected to its low pH. Both white wine and diet lemonade produced stain comparable to the water control. After treatment with high staining beverages, scanning electron microscope evaluation confirmed the formation of a surface layer. The mechanical resistance of the stain differed depending on the beverage, black tea stain was the most resistant. The addition of milk to tea and coffee considerably modified the stain layer and the adhesion to the tooth surface.

CONCLUSION

 The data may help demonstrate that appropriate user guidance can avoid stain and in turn help improve user compliance during short-term use of this gold standard antimicrobial treatment.

Color stability of 3D-printed denture resins: effect of aging, mechanical brushing and immersion in staining medium

PURPOSE

This in-vitro study evaluated and compared the color stability of 3D-printed and conventional heat-polymerized acrylic resins following aging, mechanical brushing, and immersion in staining medium.

MATERIALS AND METHODS

Forty disc-shaped specimens (10 mm in diameter and 3 mm thick) were prepared from two 3D-printed [DentaBASE (DB) and Denture 3D+ (D3D)] and one conventional polymethylmethacrylate (PMMA) denture materials. The specimens were thermo-cycled, subjected to mechanical brushing, and were immersed in either coffee, lemon juice, coke, or artificial saliva (AS) to simulate one and two years of oral use. Color measurements of the specimens were recorded by a spectrophotometer at baseline (T0), and after one (T1) and two years (T2) of simulation. The color changes (∆E) were determined and also quantified according to the National Bureau of Standards (NBS) units. Descriptive statistics, followed by factorial ANOVA and Bonferroni post-hoc test (α=.05), were applied for data analysis.

RESULTS

The independent factors, namely material, staining medium, and immersion time, and interaction among these factors significantly influenced ∆E (P<.009). Irrespective of the materials, treatments, and time, the highest and the lowest mean ∆Es were observed for PMMA in lemon juice (4.58 ± 1.30) and DB in AS (0.41 ± 0.18), respectively. Regarding the material type, PMMA demonstrated the highest mean ∆E (2.31 ± 1.37), followed by D3D (1.67 ± 0.66), and DB (0.85 ± 0.52), and the difference in ∆E between the materials were statistically significant (P<.001). All the specimens demonstrated a decreased color changes at T2 compared to T1, and this difference in mean ∆E was statistically significant (P<.001).

CONCLUSION

The color changes of 3D-printed denture resins were low compared to conventional heat polymerized PMMA. All the tested materials, irrespective of the staining medium used, demonstrated a significant decrease in ∆E values over time.

Can We Prevent Coffee Stains on Teeth?

This study evaluates whether some common beverages treated before coffee could protect or increase tooth staining caused by coffee. Initial color of 50 incisor teeth were measured with a spectrophotometer and recorded according to CIELAB color system. Teeth were randomly divided into five groups, water (control), milk, green tea, orange juice, and cola (n = 10) and were kept in selected beverage for 10 min. Immediately afterward, they were immersed in coffee and allowed to stand for 24 h. The treatment was repeated for 5 days. At the end of the fifth day, L*a*b* color measurements of the teeth were repeated. Calcium, phosphorus, potassium, and magnesium changes on representative teeth surfaces were also investigated with X-ray fluorescence spectroscopy. Color differences were calculated with both CIE_ab and CIE₀₀ formulas. Groups were compared with Kruskal-Wallis test complemented by the Bonferroni correction and Mann-Whitney U test for pairwise comparisons (P = .05). The teeth submitted to coffee challenges after distillated water or beverages showed a perceptible color change. Soaking in cola or orange juice before coffee immersion caused severe tooth discoloration. All the beverages tested here were not able to protect the tooth from coffee staining. People should be informed that some acidic beverages consumed before a coffee can worsen the coffee-based tooth discolorations.

Colour stability of stained composite resins after brushing with whitening toothpaste

OBJECTIVE

The aim of this study was to evaluate the effect of brushing with whitening toothpaste on the colour change of composite resins discoloured with coffee.

METHODS

Disc-shaped samples were prepared using one nano-hybrid (Clearfil Majesty Esthetic), one micro-hybrid (GC G-aenial Anterior) and one nano-ceramic composite (Zenit) (n = 6). After initial colour measurements, the samples were coloured in the coffee solution for 5 days. Colour measurements were made again after the colouring process, and brushing simulation was applied for 7, 15 and 30 days with two different whitening toothpastes containing calcium carbonate+perlite (Signal whitening system, SWN) and hydrated silica+hydrogen peroxide (Colgate optic White, COW) and a conventional non-whitening toothpaste containing hydrated silica (Sensodyne pronamel, SPN). Colour change (∆E₀₀ ) after brushing was calculated using the CIEDE2000 system. Repeated measures variance analysis was used for the analysis of data.

RESULTS

G-aenial anterior and Zenit showed significant coloration compared to Majesty esthetic after coloration with coffee (p < 0.05). The colour change in all composite resins was above the clinically acceptable limit (ΔE₀₀  > 1.8). Colour change over time after brushing with both whitening toothpastes differed significantly (p < 0.05). SWN and COW exhibited a significantly higher whitening effect than SPN (p < 0.05). While there was no significant difference in composite groups brushed with the SWS (p > 0.05), there was a significant difference between Majesty esthetic, G-aenial anterior and Zenit in groups brushed with COW (p < 0.05).

CONCLUSIONS

Colour change was high in micro-hybrid and nano-ceramic composites which were discoloured in coffee. The whitening toothpastes were effective in reducing the coloration caused by coffee.

Effect of acidic beverages on surface roughness and color stability of artificial teeth and acrylic resin

PURPOSE

The aim was to evaluate the effect of four acidic beverages on the roughness (Ra) and color change (ΔE_ab) of two brands of artificial teeth and a heat-polymerized acrylic resin (HPAR) for use in a prosthetic base.

MATERIALS AND METHODS

All materials were divided into 5 groups, according to the used acidic beverage (artificial saliva - control, red wine, orange juice, coke-based, and lemon juice-based soft drink). The immersion process was divided into two stages: T1 - immersion in the acidic solutions for 10 minutes for 14 days; T2 - after T1, the samples were immersed in grape juice for 14 days. The Ra of the samples was evaluated in a rugosimeter and the ΔE_ab in a spectrophotometer, before and after the immersions. The analysis of variance of one (ΔE_ab) and two factors (Ra) and Tukey were performed (α=.05).

RESULTS

There was a statistical difference for roughness after immersion (T1) for Trilux and Tritone teeth, regardless of the acid solution. For Trilux teeth, all acid solutions increased Ra (P<.05). For Tritone teeth, only the coke-based soft drink did not statistically change Ra. Grape juice (T2) altered Ra only of artificial teeth (P<.05). The color was changed for all materials, after T1 and T2.

CONCLUSION

In general, the acidic solutions changed the Ra and ΔE_ab of HPAR and artificial teeth after T1. The grape juice altered the roughness only of the artificial teeth, promoting a clinically acceptable color change in the materials.

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.

A Comparison of the Color Stability of Conventional and CAD/CAM Polymethyl Methacrylate Denture Base Materials

Objective

The aim of this study was to evaluate the color stability of a heat polymerized resin, an auto-polymerizing resin, a urethane dimethacrylate resin and a CAD/CAM PMMA block resin stored in different storage media.

Materials and methods

60 disc-shaped specimens (15×2 mm) were fabricated for each group. A total of 240 disc-shaped specimens were thermal-cycled for 5,000 cycles. Then specimens were randomized into 4 groups (n= 15) according to storage media: coffee, coke, red wine and distilled water (control group). The color measurement of each sample was performed using a spectrophotometer before and after storage (after 7 and 30 days), and color changes (ΔE) were calculated.

Results

All the denture base materials demonstrated dissimilar color changes after stored in the different storage media in both evaluation stages. In all storage media, CAD-CAM denture base resins showed the minimum in color change. In all denture base resins, red wine showed a higher degree of color change than coke or coffee.

Conclusion

The color stability of CAD-CAM denture base resins is better than any of the other kind of denture base resins. The color change values of all groups except Eclypse stored in red wine had clinically detectable values.

Surface degradation of composite resins under staining and brushing challenges

Background/purpose

The primeval evaluation of the properties of composite resins with different compositions that impact clinical behavior is very important in guiding use in clinical settings. The aim of this study was to evaluate color stability (ΔE) and Knoop microhardness (KHN) of composite resins containing different compositions.

Materials and methods

Forty-five disks were made composite resins: Filtek Z350 XT/3MESPE and Beautifill II/SHOFU and divided into 3 subgroups: Control - immersed in artificial saliva; OB - brushing with Oral B 3D White; CT - brushing with Colgate Total 12. The OB and CT groups had the disks brushed daily with 120 cycles after immersion in coffee solution (10 min) for a period of 30 days. ΔE and KHN was obtained at baseline and after the treatments. Data were analyzed ANOVA and Tukey tests (p < 0.05).

Results

ANOVA revealed significant differences for ΔE and KHN. ΔE: the highest mean was observed in Beautifil II composite resin group, which differed significantly from Z350 group. For the Beautifil II, the treatments were significantly different from each other. For the Z350, the control group showed significant differences in relation to OB e CT groups. KHN: the highest mean was observed in Z350 group, which differed significantly from Beautifil II group. For Z350, the control group showed significant differences in relation to OB e CT groups. For Beautifil II, the treatments did not differ significantly among themselves.

Conclusion

The composite resin containing fluoride in the composition showed higher color alteration (ΔE) and lower Knoop microhardness (KHN), thus demonstrating that composition is an important factor in the clinical performance of esthetic restorative materials.

Evaluation of colour change and surface roughness of two resin-based composites when exposed to beverages commonly used by children: an in-vitro study

AIM

To evaluate and compare the surface roughness and colour change of microhybrid and nanocomposite after exposure to beverages commonly used by children.

METHODS

Thirty discs were prepared using Filtek Z250 and Filtek Supreme composites. Discs were immersed in distilled water, orange juice and Coca-Cola. Colour and surface roughness were measured at baseline and on days 15 and 30.

RESULTS

Filtek Z250 and Filtek Supreme showed no significant difference in surface roughness and colour change at all measurement times. Immersion solution had a significant effect on surface roughness as well as colour change. Specimens immersed in Coca-Cola demonstrated the highest effect, followed by those immersed in orange juice, while specimens immersed in distilled water had the least effect. There was a significant increase in surface roughness and colour change over time. The change in colour was more evident in the period between baseline measurements and after 15 days. There was a significant interaction between media type and time.

CONCLUSIONS

Both composites showed no significant difference in roughness and colour change at all measurement times. There was a significant increase in surface roughness and colour change in all immersion solutions tested over time. Coca-Cola caused unacceptable colour change.

Effect of alcoholic beverages on shear bond strength of composites to enamel

Background:

Longevity of composite restoration in the oral cavity is dependent on various factors. One such factor is exposure to various foods and beverages which could alter the properties of the material.

Aim:

The aim of this in vitro study was to evaluate the effect of most widely consumed alcoholic beverages on shear bond strength of composites to enamel.

Material and Methods:

A total of seventy human premolars were embedded in acrylic resin blocks. Labial enamel surfaces was flattened, etched, bonded, and restored with composite resin (Tetric N Ceram – Ivoclar Vivadent AG, Schaan, Liechtenstein). The specimens were randomly divided into four groups: Group I: beer; Group II: wine; Group III: whiskey, and Group IV: artificial saliva. Group I to Group III were again divided into moderate (Group IA, IIA, and IIIA) and heavy (Group IB, IIB, and IIIB) consumption subgroups. The specimens were soaked in their respective groups for 90 min daily in Group IA, IIA, and IIIA and for 30 min every alternate day in Group IB, IIB, and IIIB until 30 days. Universal testing machine was used to determine the shear bond strength of composite with enamel.

Statistical Analysis Used:

The values obtained were statistically analyzed using two-way analysis of variance followed by post hoc test with the significant level set at P < 0.05, using GraphPad prism software version 6.01.

Results:

Group IIB showed the highest reduction in shear bond strength, with a mean value of 6.6 ± 1.2 Mpa in comparison to control with a mean value of 21.8 ± 1.6 Mpa.

Conclusion:

As the content of alcohol and time of exposure increased along with a decrease in the pH of alcoholic beverages, shear bond strength between composite and enamel decreased.

Evaluation of the staining potential of silver diamine fluoride: in vitro

BACKGROUND

Silver diamine fluoride (SDF) is a cariostatic agent used to adjunctively manage dental caries in high-risk groups. However, black staining is a frequently reported side effect following SDF application and influences the acceptability of this treatment.

AIM

To evaluate the staining potential of SDF and the influence of the potassium Iodide (KI) application on the degree of black staining over time.

DESIGN

Extracted carious primary molars were collected and sorted into pairs matched by tooth type, size and location of the carious lesion (n = 35). Teeth were stratified to receive either 38% SDF, KI immediately after SDF application, or 12% SDF. Standardised timelapse photography and image processing software was used to evaluate staining over a period of 7 days.

RESULTS

Following SDF application, the onset of black staining occurred within 2 min and increased in value for up to 6 h post-application. The use of KI immediately after SDF application resulted in no noticeable staining of the carious dentine or surrounding enamel. No significant differences were evident in the staining potential between the different SDF concentrations (38% and 12%). Furthermore, root surface and cementum was found to stain darker and more readily when compared with the coronal enamel surface.

CONCLUSION

SDF has the ability to visibly stain dental hard tissues and its staining potential may be modified by application of KI.

The relevance of alcohol to dental practice

Alcohol is a very widely used drug which can cause dental disease and influence dental treatment. It is therefore important that dental professionals take an alcohol history from all patients and are aware of how to give alcohol reduction advice. This article discusses the impact of alcohol on oral health, including oral cancer, trauma, halitosis, tooth wear, periodontal disease and caries, with reference to the available literature. It also outlines current alcohol risk level advice and guidance regarding giving alcohol reduction advice in a dental setting.

Evaluation of color changes of dental luting materials in food colorant solutions

BACKGROUND

The purpose of this study was to compare the color stability and water absorption of 3 commercially available resin cements in vitro by storing them in 0.15% erythrosine, dark brown and sunset yellow for 30 days.

METHODS

2 self-adhesive resin cements and 1 dual/light curing, resin-based dental luting material were evaluated (total 120 samples). The CIE L, a, b of 10 mm diameter-2.0 mm height disk shaped samples was measured using a spectrophotometer for color stability on a white background, 10 mm diameter-1.0 mm height disk shaped samples were measured for water absorption before and after storage in food colorant solutions.

RESULTS

The self-adhesive resin cement-sunset yellow group caused the most severe discoloration (27.89 ± 3.64) that is clinically unacceptable. The lowest discoloration was seen in the self-adhesive resin cement control group (3.35 ± 1.13). The highest water absorption was observed in the self-adhesive resin cement-dark brown group (2.41 ± 0.60) and the lowest water absorption in the dental luting material-control group (0.65 ± 0.17).

CONCLUSIONS

Storage food colorant solutions affected the color stability and water absorption of different resin cement materials.

In vitro evaluation of a silica whitening toothpaste containing blue covarine on the colour of teeth containing anterior restoration materials

OBJECTIVES

To investigate the effects of a silica-based whitening toothpaste containing blue covarine on the colour of restorations in extracted human teeth.

METHODS

Human extracted teeth were mounted in acrylic resin. A cavity was cut into the enamel surface and the specimen restored with either glass ionomer or composite dental materials. Following 4 weeks storage in water, specimens were treated with either water, red wine or a toothpaste containing blue covarine (n=10) for 24h followed by brushing with a silica-based toothpaste. Specimens were imaged with a digital imaging system at baseline, after 24h treatment and after brushing with a silica-based toothpaste. CIELAB colour parameters were determined for the restoration and the whole specimen and overall mean colour changes calculated (ΔE). Baseline and post-brushing images were compared subjectively for overall stain and staining around the restoration margin.

RESULTS

Red wine produced the largest ΔE values for whole specimens and for all restoration materials and the largest subjective stain scores for whole specimens and restoration margins. The red wine stain was not completely removed by brushing with a silica-based toothpaste. Comparisons of the red wine group with either the blue covarine toothpaste group or the water group were of statistical significance for all parameters (ANOVA, Tukey-Kramer, p<0.05). Following brushing with the silica-based toothpaste, specimens from the blue covarine toothpaste group were not significantly different (p>0.05) to the water group, for all restoration material types.

CONCLUSIONS

Exaggerated treatment with a blue covarine containing toothpaste does not significantly affect the colour of the restoration or the restoration margin of the dental materials tested versus a water alone treatment.

CLINICAL SIGNIFICANCE

The silica-based blue covarine containing toothpaste does not permanently stain the restorative materials tested or their margins.

The combined effect of food-simulating solutions, brushing and staining on color stability of composite resins

Objective: This study evaluated the effect of food-simulating media associated with brushing and coffee staining on color stability of different composite resins.

Materials and methods: Eighty specimens were prepared for each composite: Grandio SO (Voco), Amaris (Voco), Filtek Z350XT (3M/ESPE), Filtek P90 (3M/ESPE). They were divided into four groups according to food-simulating media for 7 days: artificial saliva (control), heptane, citric acid and ethanol. The composite surface was submitted to 10,950 brushing cycles (200 g load) in an automatic toothbrushing machine. The specimens were darkened with coffee solution at 37 °C for 24 h. After each treatment, color measurements were assessed by spectrophotometry, using CIE L*a*b* system. The overall color change (ΔE) was determined for each specimen at baseline (C1) and after the treatments (food-simulating media immersion/C2, brushing/C3 and dye solution/C4). Data were analyzed by two-way repeated measures ANOVA and Tukey’s tests (p < .05).

Results: The results of RM-ANOVA showed significant differences for composites (p = .001), time (p = .001) and chemical degradation (p = .002). The mean of ΔE for composites were: Z350XT (5.39)^a, Amaris (3.89)^b, Grandio (3.75)^bc, P90 (3.36)^c. According to food-simulating media: heptane (4.41)^a, citric acid (4.24)^a, ethanol (4.02)^ab, artificial saliva (3.76)^b. For the treatments: dye solution (4.53)^a, brushing (4.26)^a, after food-simulating media (3.52)^b.

Conclusions: The composite resin Filtek Z350XT showed significantly higher staining than all other composite resin tested. The immersion in heptane and citric acid produced the highest color alteration than other food-simulating media. The exposure of samples to brushing protocols and darkening in coffee solution resulted in significant color alteration of the composite resins.

Effect of Salivary pH on Color Stability of Different Flowable Composites - A Prospective In-vitro Study

INTRODUCTION

Scientifically and clinically there has been lot of development in the field of aesthetic dentistry. However, there is limited or restricted information regarding the color stability of flowable composite materials.

AIM

The aim of this study was to evaluate the spectrophotometric color stability of three different flowable composite materials with respect to three different pH of saliva.

MATERIALS AND METHODS

The study included 90 different samples. Thirty samples in each composite group; (Group A: G-aenial universal flo; Group B: Z 350 XT flowable; Group C: Esthet x flow). All samples from each group were immersed in distilled water for 24 hours. Total color difference (ΔE) was recorded for each sample. After this 10 samples from each group were respectively immersed in 6.5, 7 and 7.5 pH of artificial saliva. All samples were kept in dark room for seven days and then ΔE for each sample was recorded and was compared to previous recorded ΔE for the same sample.

RESULTS

Maximum color change was seen irrespective of material in 6.5 pH of saliva. G-aenial universal flo showed least change irrespective of pH of saliva.

CONCLUSION

Thus, the present study reveals that acidic pH level affects the coloration of composite resins by affecting the surface integrity and as reported in previous studies, various coloring agents in beverages and other dietary components assists the process due to absorption of these coloring substances into the resin matrix.

Six-month color change and water sorption of 9 new-generation flowable composites in 6 staining solutions

Color match and water sorption are two factors that affect restorative materials. Discoloration is essential in the lifespan of restorations. The aim of this study was to evaluate color change and water sorption of nine flowable composites at multiple time points over 6 months. 60 samples of each composite were divided into two groups (Color Change and Water Sorption/Solubility). Each Color Change group was divided into six subgroups, which were immersed in distilled water (DW), coffee (CF), Coca-Cola (CC), red wine (RW), tea (TE) and orange juice (OJ). The color was measured at the baseline, 1, 2, 3 and 4 weeks, and 3 and 6 months and color change values (ΔE) were calculated. Each Water Sorption [WS]/Solubility [WL] group was tested according to ISO 4049:2009. The data were evaluated using two-way ANOVA, Fisher's post-hoc test and Pearson's correlation test. The composite with the lowest ΔE differed for each solution: Filtek™ Bulk Fill in DW (∆E = 0.73 (0.17-1.759)); Vertise Flow in CF (∆E = 14.75 (7.91-27.41)), in TE (∆E = 7.27 (2.81-24.81)) and OJ (∆E = 3.17 (0.87-9.92)); Tetric EvoFlow® in CC (∆E = 1.27 (0.45-4.02)); and Filtek™ Supreme XTE in RW (∆E = 8.88 (5.23-19.59)). RW caused the most discoloration (∆E = 23.62 (4.93-51.36)). Vertise Flow showed the highest water sorption (WS = 69.10 ± 7.19). The Pearson test showed statistically significant positive correlations between water sorption and solubility and between water sorption and ∆E; the positive solubility-∆E correlation was not statistically significant. The findings suggest that water sorption is one factor associated with the ability of composites to discolor; however, discoloration is a multifactorial problem.

The effect of red and white wine on color changes of nanofilled and nanohybrid resin composites

Objectives

This study investigated the effect of red and white wine on color changes of nanofilled and nanohybrid resin composite.

Materials and Methods

Sixty specimens of each resin composite were prepared. Baseline data color values were recorded using a spectrophotometer. Three groups of discs (n = 20) were then alternately immersed in red, white wine, and deionized water (as a control) for twenty five minutes and artificial saliva for five minutes for four cycles. Specimens were then stored in artificial saliva for twenty two hours. This process was repeated for five days following immersion in artificial saliva for two days. Subsequently, the process was repeated again. Data were analyzed by two-way repeated ANOVA, one-way ANOVA, and Tukey's HSD.

Results

Red wine caused significantly higher color change (ΔE^* > 3.3) than did white wine and deionized water (p < 0.05). Nanohybrid resin composites had significantly more color changes than nanofilled resin composite (p < 0.05).

Conclusions

The effect of red and white wine on the color changes of resin composite restorative materials depended upon the physical and chemical composition of the restorative materials and the types of wine.

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.

Effect of the Purple Corn Beverage "Chicha Morada" in Composite Resin during Dental Bleaching

During dental bleaching the staining potential of the surface would increase. This study aims to evaluate the staining susceptibility of one bleached composite resin after the exposure to three different beverages: Peruvian purple corn based beverage (chicha morada), green tea, and distilled water. Thirty disk-shaped specimens of one nanofill composite resin were prepared. The specimens were then divided into six groups (n = 5): purple corn (P), purple corn + bleaching (PB), green tea (T), green tea + bleaching (TB), distilled water (W), and distilled water + bleaching (WB). In groups that received bleaching, two sessions of bleaching with 35% hydrogen peroxide were done. Following bleaching, specimens were exposed to each liquid thirty minutes daily. Color was measured with a digital spectrophotometer. For statistical analysis, color measurement differences between the obtained results were used: during bleaching, after bleaching, and during + after bleaching. Two-way ANOVA was used to compare the color changes in the resins of all groups (p < 0.05). We conclude that all the evaluated beverages produced changes of color in the composite resin regardless of the bleaching procedure. However, purple corn was the only beverage that caused a perceptible color change (ΔE > 3.3).

Evaluation of Stain Penetration by Beverages in Demineralized Enamel Treated With Resin Infiltration

PURPOSE

To evaluate stain penetration by different beverages in artificially demineralized human teeth treated with resin infiltration.

METHODS AND MATERIALS

Sixty extracted human permanent molars were demineralized, treated with resin infiltration (Icon), and immersed in four different beverages (coffee, grape juice, iced tea, and distilled water; N=15) for four weeks. After aging, teeth in the distilled water group were stained with 2% methylene blue for 24 hours. All teeth were sectioned, and stain penetration was evaluated under light microscopy. Chi-square test, independent and paired sample t-test, analysis of variance with the Fisher least significant difference post hoc test, and the Kruskal-Wallis test were used to analyze the results (p<0.05).

RESULTS

Resin infiltration-treated surfaces (Icon surfaces) had statistically significant fewer samples with presence of stain penetration compared to untreated surfaces (control surfaces) (p<0.001). There was also a significant decrease in depth of stain penetration in Icon surfaces compared to the control surfaces (p<0.001). Among tested beverage groups, iced tea showed significantly greater depth of stain penetration (0.134±0.029 mm), followed by grape juice (0.118±0.047 mm), methylene blue (0.022±0.019 mm), and coffee (0.008±0.017 mm; p<0.001).

CONCLUSION

Both Icon and control surfaces exhibit stain penetration by different beverages (iced tea, grape juice, and coffee). However, resin-infiltrated enamel surfaces allow significantly less depth of stain penetration compared to untreated surfaces. The iced tea group presents greatest depth of stain penetration, followed by grape juice, methylene blue, and coffee.

Color stability and surface roughness of polished anterior restorative materials

The purpose of this study was to investigate the effects of different finishing-polishing techniques on the color stability and surface roughness of various anterior restorative materials after staining. A composite, a compomer, and a resin-modified glass ionomer were used to prepare 120 specimens. Specimens were divided into subgroups: polishing discs, liquid polishing material, aluminium oxidebonded discs, and control. The specimens were stained in a coffee solution. Color parameters (L*a*b*) and surface roughness before and after staining were measured. The color was affected by the material type (p<0.05) and finishing-polishing systems (p<0.05). The composite showed the highest color stability; however, the color differences of all groups were visible even to the nonskilled operator. The Ra values did not significantly change after staining for any of the restorative groups (p>0.05). The finishing-polishing systems had an effect on color after storing in staining solution.

Effect of toothbrushing on color changes of esthetic restorative materials

PURPOSE

The aim of this study was to evaluate the effects of various drinks and toothbrushing on the color changes of esthetic restorative materials used in pediatric dentistry.

MATERIALS AND METHODS

Forty specimens were prepared from each of three restorative materials (compomer [Dyract AP], glass ionomer cement [Ionofil Molar AC, Voco], composite resin [Filtek Z 250]). Specimens were divided into four groups for immersion in three different staining solutions (cherry juice, cola, chocolate milk) and distilled water. Each group was subdivided into brushing and non-brushing groups. The specimens in the brushing subgroups were brushed with toothpaste once a day using an electric toothbrush. Color was measured using a colorimeter, and color changes were calculated between baseline and 1, 7, 30, 60 days. Data was analyzed using Kruskal-Wallis, Mann-Whitney U, Wilcoxon, and Wilcoxon Signed Rank tests.

RESULTS

All the solutions evaluated yielded color changes, and these changes were significantly greater for composite resin than for glass ionomer cement or compomer (p < 0.006). Brushing significantly decreased the color changes of restorative materials (p < 0.004).

CONCLUSION

Brushing significantly influenced the color stability of esthetic restorative materials. The results of this study also showed that glass ionomer cements and compomers had higher color stability than composite resins.

CLINICAL SIGNIFICANCE

The color stability values after brushing may better reflect the discoloration of the esthetic restorative materials. Any color stability study model should consider the effects of toothbrushing that can remove the adsorbed colorants. The results of this study also showed that glass ionomer cements and compomers can be used in anterior restorations of children with their higher color stability than composite resins.

Colour Stability of Self-Adhesive Flowable Composites before and after Storage in Water

Objectives:The aim of this study was to compare colour stability of two self-adhesive flowable composites with four methacrylate-based composites (three flowable composites and one universal resin-based composite) after immersion in water at 60°C for 30 days.Methods:The study was conducted using the following five shade A2 flowable composites (n=30): one microhybrid (G-aenial Universal Flo), one universal (X-Flow), one nanohybrid (Premise flowable) and two self-adhesive (Vertise Flow and experimental GF-10) and one microhybrid universal resin-based composite (G-aenial Posterior). A spectrophotometer (CIEL*a*b* system) was used to measure colour stability before and after immersion. Statistical analysis was performed with one-way ANOVA and Fisher test.Results:Samples immersed in water at 60°C for one month showed a significant colour change in all groups (p<.001) that was visually perceptible (∆E>3.3). Experimental self-adhesive flowable (12.25±0.84) and X-Flow (11.56±3.26) composites showed higher levels of ∆E, while Premise flowable showed a lower level of colour change (3.47±1.26). These results approximated clinically acceptable colour change values (∆E≤3.3). Water ageing at 60°C produced a significant change in colour in all the composites. The high temperature may explain the degradation of the resin matrix.

Spectrophotometric evaluation of color changes of bleach-shade resin-based composites after staining and bleaching

Spectrophotometric evaluation of color changes of Bleach-shade resin-based composites after staining and bleaching.

AIM

The aim of this study was to evaluate the color stability of two commercially available bleach-shade resin composites (RC) after exposure to 3 storage solutions and the effect of 3 bleaching agents on the color stability and stain removal from stained RC.

MATERIALS AND METHODS

Two bleach-shade RC were evaluated in this study, including a nanoflled RC, Filtek(TM) Z350 XT (FZ), and a nanohybrid RC, Tetric(®) N-Ceram (TC), in the extra-white body (shade) (XWB) and L shades, respectively. Twenty-seven disk-shaped specimens, each measuring 12 mm in diameter and 2 mm in thickness, were prepared for each RC, with a total of 54 specimens. Specimens were randomly allocated into 3 groups of 9 specimens each and immersed in 3 storage solutions (distilled water, tea and coffee) for 7 days period. The 9 specimens in each staining group were further divided into 3 subgroups. Specimens in each subgroup (n = 3) were bleached using one of the bleaching agents (10 and 16% Zoom NiteWhite amorphous calcium phosphate (ACP), and Zoom 2 chairside with light activation) for 5 days period. The specimen colors were measured with spectrophotometer. The measurements were performed on each sample three times at baseline, after staining, and after bleaching. Color was expressed using the commission international de I'Eclairage (CIE) L*a*b* color space. The color differences (ΔE) between the three measurements were calculated and the results were statistically analyzed using Two-way and Three-way analysis of variance (ANOVA) and Tukey's posthoc tests. Level of significance was set at p < 0.05.

RESULTS

Tetric(®) N-ceram materials demonstrated significantly less color change than the FZ and the color change, which was greater after storage in coffee compared to tea, was statistically significant. The bleaching agents significantly influence the color changes of composite specimens. All groups showed (ΔE) values below 3.3 after bleaching, except for 'Zoom 2 chairside' with light activation groups, which is shown clinically unacceptable lighter shade (ΔE >3.3).

CONCLUSION

Bleach-shade composites showed significant discoloration (ΔE > 3.3) after being immersed into coffee and tea solutions. Nanoflled composites discolored more than nano-hybrid composites, and carbamide peroxide-based bleaching agents were effective in reducing the discoloration to a clinically acceptable value (ΔE > 3.3).

Physical properties of polyamide-12 versus PMMA denture base material

OBJECTIVES

Polyamide-12 (PA) is a flexible material suited for denture bases and clasping. This study investigated its potential aging effects with a focus on surface roughness, color stability, and elasticity.

METHODS

PA specimens (Valplast) of 40×10×2 mm and equally measuring PMMA specimens (Palapress) as control were fabricated. Color changes after storage in air, water, coffee, and red wine (n=10) were measured using the CIE L*a*b* color specification. Elasticity after thermocycling (1000, 3000, and 7000 cycles,  n=15) was measured by three-point bending testing. Mean surface roughness (Ra) was determined after storage in the liquids mentioned above and thermocycling (n=10).

RESULTS

Tukey's HSD test (P<0.05) revealed statistically significant color changes of PA in red wine (ΔE=4.27 after 12 days, ΔE=6.90 after 12 days) and coffee (ΔE=3.93 after 36 days) but no color changes in PMMA. Elastic modulus of PA was 845 MPa and not affected by thermocycling (Tukey's HSD test,  P>0.81). Dry specimens showed significantly decreased elasticity (P<0.001). Mean surface roughness (PA 0.20  μ m, PMMA 0.28  μ m) did not change significantly after thermocycling or storage (Mann-Whitney U-test,  0.16<P<0.65).

SIGNIFICANCE

PA exhibited a higher susceptibility to discoloration than PMMA. Neither surface roughness nor elasticity of PA was altered by artificial aging.

Effect of cigarette smoke on color stability and surface roughness of dental composites

OBJECTIVE

To evaluate the color stability and surface roughness of 3 dental composites subjected to cigarette smoke and brushing.

METHODS

Twenty specimens were prepared for each type of restorative material used: nanohybrid (Tetric N-Ceram); hybrid (Z250-3M ESPE) and silorane-based microhybrid (Filtek P90-3M ESPE), which were divided into 2 groups (n=10), according to the type of finishing/polishing received: Group 1 - papers with decreasing abrasive grit and Group 2 - polyester matrix (without polishing). After initial readouts of color (Easy Shade-VITA) and surface roughness (SJ-201P Mitutoyo), specimens were subjected to action of smoke from 20 cigarettes, (Marlboro Red-Philip Morris). After each cigarette, the samples were submitted to brushing in a standardised device. After this, final readouts were taken to calculate change in color (ΔE and ΔL) and roughness (ΔRa), which were statistically analysed (2-way ANOVA, Bonferroni, and Student's-t tests respectively, p<0.05).

RESULTS

Tetric N-Ceram presented color change at clinically unacceptable levels (ΔE>3.3) when the polyester strip was used for finishing, a result differing (p<0.05) from those of the other composites, which presented no difference between them (p>0.05). Unpolished composites presented higher Ra values than those that were polished (p<0.05), with exception of the silorane based composite.

CONCLUSION

Absence of polishing increases cigarette capacity to stain composites and surface roughness of composites, with exception of the silorane based type.

Effects of commonly consumed beverages on surface roughness and color stability of the nano, microhybrid and hybrid composite resins: an in vitro study

BACKGROUND

Consumption of certain beverages may affect the esthetic and physical properties of the resin composite, thereby undermining the quality of restorations.

AIM

To analyze the effect of three beverages (cola, coffee, tea) on color stability and surface roughness of three different types of resin composites at various time intervals in vitro.

MATERIALS AND METHODS

Nano, microhybrid and hybrid resin composites were used. Each material was randomly divided into four equal subgroups of 10 samples each according to the beverages used (cola, coffee, tea, distilled water). The samples were immersed in each beverage for 1, 15 and 30 days. Surface roughness and color changes measurements were noted at the baseline-the first, fifteenth and thirteenth day.

RESULTS

It was found that nanoresin composite followed by microhybrid and hybrid showed least surface roughness and color change. The Coke beverage subgroup showed more surface roughness and the subgroup coffee has shown more color changes with respect to other subgroups.

CONCLUSION

All specimens showed discoloration after completion of the test period which was visually perceptible and clinically unacceptable. At the end of 30th day, among the materials, nanofilled composite resin showed comparatively less surface roughness and color change than microhybrid and hybrid composite resins.