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- Eur J Dent
- v.8(2); Apr-Jun 2014
- PMC4054058
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Eur J Dent. 2014 Apr-Jun; 8(2): 249–253.
PMCID: PMC4054058
PMID: 24966778
Muhammet Karadas1 and Nilgun Seven2
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Abstract
Objective:
This study evaluated the influence of coffee, tea, cola, and red wine staining on the color of teeth after home bleaching.
Materials and Methods:
A total of 45 samples were obtained from 45 sound maxillary central incisors. The home bleaching procedure was performed using 10% carbamide peroxide gel applied to the sample surface for a period of 6 h each day, for 14 days. After bleaching, baseline color measurements were taken, and the samples were immersed in four staining solutions (coffee, tea, cola, and red wine) or artificial saliva (n = 9). Following 15 min and 6 h of immersion on the first day and next day, respectively, the samples were washed with distilled water for 10 s. After 15 min, 6 h, 1 week, and 1 month immersions, the color values of each sample were remeasured and the color change values (∆E) were calculated. Color change analysis was performed using a spectrophotometer. The results were analyzed using analysis of variance and Tukey's honestly significant difference test (P <0.05).
Results:
Of all the staining solutions, the lowest ∆E values were observed with coffee staining versus artificial saliva (control group), for all time intervals evaluated after whitening. Although no statistically differences were observed between the coffee and control group at all the time points evaluated, there were statistically significant differences between the red wine, cola, and tea solutions.
Conclusion:
Following tooth whitening, patients should avoid drinks that cause tooth staining, particularly red wine, tea and cola.
Keywords: Bleaching, color change, spectrophotometry
INTRODUCTION
Bleaching treatment is an effective method for restoring the color of discolored vital teeth,[1] and has been associated with peroxide concentration and bleaching time.[2] Another significant factor regarding the efficacy of bleaching techniques is patient cooperation, particularly with regard to home bleaching.[3]
The home bleaching technique, introduced by Haywood and Heyman[4] in 1989, involves selfapplication of 10% carbamide peroxide, in a customfitted plastic tray, used nightly for approximately 6 to 8 h, for a period ranging from 2 to 6 weeks. Bleaching mechanisms are based on the application of hydrogen peroxidereleasing agents. Hydrogen peroxide may be applied directly, or it may be produced from carbamide peroxide. It penetrates the tooth and produces free radicals, which then attack and break apart the chromophore bonds of large, longchain, dark colored molecules, eventually breaking these molecules down so far that they have no chromophore bonds, which results in the whitest possible teeth.[5]
Dentists advise patients to reduce the consumption of coffee and tea, and to avoid smoking or any other habit that may cause the teeth to stain, particularly after bleaching treatment, because some studies have reported that bleaching agents can alter the texture and morphology of the enamel surface.[6] There may be a loss of organic components from bleached enamel and dentin surfaces. Changes in the microstructure of teeth may be partly due to the loss or denaturing of protein,[7] and these alterations may facilitate the recurrence of extrinsic staining.[8] Therefore, it is significant to evaluate the effects of staining substances during and after bleaching treatment.
Certain beverages, artificial food colorings, and smoking are thought to be the most significant causes of primary coloration.[9] Studies investigating the way in which consumed staining substances can affect the results of the bleaching process after treatment are rare. Therefore, in study, we evaluated the influence of coffee, tea, cola, and red wine staining on the color of teeth after bleaching with 10% carbamide peroxide.
MATERIALS AND METHODS
The research protocol was approved by the Clinical Research Ethical Committee of Erzurum Provincial Health Directorate. This study was carried out at the Atatürk University of Dentistry. A total of 45 sound maxillary central incisors, extracted for periodontal and several reasons a month previously, were used. Following extraction, the teeth had been stored in 8% thymol solution. Dental calculus and periodontal membrane remnants were removed using hand tools. The roots were sectioned from the dentinoenamel junction using a watercooled diamond saw (Impect PC10, Equilam Lab Equip, Brazil). Using rectangle moulds, each specimen, with the labial surface exposed, was individually submerged in chemically cured acrylic resin, through which light passes. After preparation, the samples were polished, using a prophylaxis paste administered via a polishing brush, and washed.
For the dental bleaching technique, 10% carbamide peroxide (Opalescence 10%, Ultradent Products, USA) was placed on each sample surface, using a dispenser tip, forming a layer that was 0.5 to 1 mm thick. Bleaching agent was left in contact with each tooth sample for a period of 6 h each day, and was subsequently removed using cotton and rinsing. During bleaching intervals, specimens were maintained in artificial saliva,[10] changed daily, at 37°C until further use. This procedure was repeated on a daily basis for a total of two consecutive weeks.
After bleaching, the samples were randomly divided into five groups (n = 9), according to the colourant solutions: Artificial saliva (control group), red wine (DLC Öküzgözü 2009, Doluca, Turkey), coffee (Nescafe 3 in 1, Turkey; the coffee mixture was prepared by dissolving 4 g of coffee in 200 ml of boiling distilled water), cola (CocaCola, Turkey), and tea (Yellow Tea, Lipton, Turkey; the tea mixture was prepared by leaving a tea bag in 175 -ml of boiling water for 5 min). Immersion time was selected as the 15 min, 6 h, 1 week and 1 month. According to manufacturer, the average daily consumption of coffee is 15 min.[11] Therefore, 1 month immersion time for 6 h per day simulates about 24 month of drinks consumption.
The initial color values of the samples were measured 24 h after bleaching treatment, and assessed according to the CIELAB color system with a spectrophotometer (Shadepilot, DeguDent GmbH, Rodenbacher Chaussee 4, MHT Optic Research AG, 63457 Hanau, Germany) connected with a personal computer in a standardized condition. Each prepared sample was placed on the table, and the suitable mouthpart of the spectrophometer's camera was later placed at a 90 degree angle to the sample surface, which was centred in the yellow target box represented on the computer monitor. The spectrophotometer was calibrated prior to measurement of each color, with white and green ceramics provided by its makers. Following 15 min and 6 h of immersion on the first day and next day, respectively, the samples were washed with distilled water for 10 s and immersed in artificial saliva for the remainder of the day. All of the staining solutions were renewed daily. Immersion color measurements were performed after 15 min, 6 h, 1 week, and 1month. The spectrophotometric documents relating to each sample were saved by the same operator at their personal computer. All colour measurements were taken three times at different places on the middle third of each sample surface using the inbuilt synchronized image program. The color of each sample was taken as the average of three measurements, which were used for overall document analysis. The size of the circular areas used for analysis was 5 mm per sample.
Color change (∆E*ab) was calculated by the equation ∆E*ab = [(∆L*)2+ (∆a*)2+ (∆b*)2]1/2. When the ΔE was higher than 3.7, it was considered an easily visible difference. When it was between 3.7 and 1, it was considered a clinically acceptable difference, and when the ΔE was less than 1, the difference was considered to be not clinically visible.[12]
Statistical analysis
After ∆E*ab values were calculated, we performed a repeated measures analysis of variance on the results for comparison of measurements taken at four separate intervals (time factors). We then used the post hoc Tukey test to determine differences among groups. Differences were considered statistically significant when P < 0.05.
RESULTS
The mean ∆E values and standard deviations for all groups are represented in Table 1. For all the staining solutions, excluding artificial saliva (the control group), the lowest ∆E values were observed with the coffee solution at all time intervals evaluated after bleaching. There were no statistically significant differences in color between artificial saliva and coffee at all time intervals evaluated after bleaching, whereas significant differences were found between artificial saliva and tea, red wine, and cola solutions at all these time points.
Table 1
Mean ΔE values and standard deviations
Open in a separate window
After a 1 month immersion, the highest color difference was observed with the cola solution. Color change in the samples was easily visible difference after a 1 month immersion in artificial saliva (4.19), after a 1 week immersion in coffee solution (3.93), and after a 6 h immersion in tea (9.99), red wine (11.01), or cola (8.75) solution. Distribution of CIE L* values, CIE a* values, and CIE b values in staining solutions are shown in Figures Figures11–3, respectively. In red wine solution, CIE b values decreased, while these values increased with regard to the other solutions.
Figure 1
Changing CIE L* values of samples within the observation period
Figure 3
Changing CIE b* values of samples within the observation period
Figure 2
Changing CIE a* values of samples within the observation period
DISCUSSION
A number of methods are available for evaluating tooth shade changes after bleaching, following immersion in coloring solutions. These can be classified as subjective, such as the use of a standard tooth shade guide, and objective, such as use of spectrophotometers,[13] colorimeters and computer digitization.[8] In this study, in order to achieve more consistent and accurate results, we used a spectrophotometer (shadepilot). Shadepilot allows completely accurate evaluation of spectral data, unaffected by light sources in the surgery or other ambient light.
The surfaces of the samples were not ground flat before the experiment, as we wanted to investigate the teeth under natural conditions. However, this might have led to a greater variation among the specimens, with respect to the adsorption of stain and the determination of the color, because of some irregularities in the surface composition of the samples. All the samples were thoroughly cleaned and polished before the experiment. This is common practice, and it is recommended that the teeth are thoroughly cleaned prior to bleaching.
We stored the samples in artificial saliva throughout the experiment, as we wanted to simulate both the remineralization of the bleached specimens[14] and the impact of saliva as being significant in the formation of tooth staining.[15,16] It is debatable as to whether microstructural defects may be repaired by remineralization.[9]
Numerous previous studies have evaluated the adverse effects of peroxidecontaining bleaching products on tooth enamel, with conflicting results. Some studies have reported no significant deleterious effects on the surface microstructure of the enamel and dentine after bleaching treatment.[17,18] However, others have actually shown a deleterious effect on the enamel and/or dentine, such as alteration of surface morphology.[19,20] Staining susceptibility cannot be related to surface roughness alone, but to enamel composition, water absorption rate, due to permeability alterations, and irregularities left on bleached enamel surfaces, which could facilitate the accumulation of dye.[20,21,22,23,24]
Some foods and beverages are known to cause tooth staining.[25] Some of these are acidic solutions that can increase demineralization, while others contain ethanol and pigments.[9,26] Tooth discoloration is dependent on a variety of factors, such as the pH value of the staining solution.[27] In this study, cola had the lowest pH and may have damaged the surface of the samples; it showed the highest ∆E* value 1 month and 1 week after immersion.
In view of the previously demonstrated coloring effects of staining solutions in contact with the dental structure,[28] the color stability obtained in dental bleaching should be considered as strongly linked to the dietary habits of patients, both during and after the conclusion of the bleaching process. In a previous study,[29] no significant difference was detected between photoreflectance analysis of specimens exposed to coffee solution and specimens not exposed to coffee solution after 28 days of bleaching treatment, but, when the teeth were exposed to a coffee solution during home bleaching, the whitening effect appeared to be less stable. Similarly, in our study, no statistically difference was detected between coffee and the control group at any time after bleaching.
Pini et al.[30] found statistically significant differences between teeth treated with coffee and wine after bleaching, compared to a control group. However, another study[31] demonstrated that bleached enamel was susceptible to red wine staining after bleaching procedures, whereas coffee did not interfere with the bleaching process. In this study, although no statistically differences were observed between coffee and the control group at any time, there were statistically significant differences between red wine and the control group at all time points evaluated.
In this study, with the exception of artificial saliva, coffee consistently showed the lowest ∆E* value at all times evaluated. At 6 h after being immersed in tea, red wine or cola, at 1 week after immersion in coffee and at 1 month after immersion in artificial saliva, color change values were greater than 3.7. Coffee and tea contain yellow colorants that have different polarities, which may explain the discoloration of the composite samples observed after immersion in tea or coffee.[32] Our results showed that tea and coffee caused different discoloration. We also found that b* values decreased over time in red wine, due to the presence blue pigments, although they increased over time in cola, coffee, artificial saliva, and tea.
CONCLUSION
On the basis of the experimental conditions in this study, and within the limitations of an in vitro investigation after bleaching, we drew the following conclusions:
Although we observed no statistically differences between coffee and the control group at any time evaluated, we found statistically significant differences between red wine, cola, tea, and the control group for all evaluated time points
Red wine, cola, and tea caused more staining than coffee
The cola showed the highest ∆E* value after a 1-month and a 1-week immersion
After being immersed in tea, red wine, and cola for 6 h, after a 1-week immersion in coffee, and after a 1-month immersion in artificial saliva, color change values were greater than 3.7.
Footnotes
Source of Support: Nil.
Conflict of Interest: None declared
REFERENCES
1. McEvoy SA. Chemical agents for removing intrinsic stains from vital teeth. II. Current techniques and their clinical application. Quintessence Int. 1989;20:379–84. [PubMed] [Google Scholar]
2. Matis BA, Mousa HN, Cochran MA, Eckert GJ. Clinical evaluation of bleaching agents of different concentrations. Quintessence Int. 2000;31:303–10. [PubMed] [Google Scholar]
3. Odioso LL, Gibb RD, Gerlach RW. Impact of demographic, behavioral, and dental care utilization parameters on tooth color and personal satisfaction. CompendContinEduc Dent Suppl. 2000:S35–41. quiz S43. [PubMed] [Google Scholar]
4. Haywood VB, Heymann HO. Nightguard vital bleaching. Quintessence Int. 1989;20:173–6. [PubMed] [Google Scholar]
5. Joiner A. The bleaching of teeth: A review of the literature. J Dent. 2006;34:412–9. [PubMed] [Google Scholar]
6. Cavalli V, Giannini M, Carvalho RM. Effect of carbamide peroxide bleaching agents on tensile strength of human enamel. Dent Mater. 2004;20:733–9. [PubMed] [Google Scholar]
7. Zimmerman B, Datko L, Cupelli M, Alapati S, Dean D, Kennedy M. Alteration of dentin-enamel mechanical properties due to dental whitening treatments. J MechBehav Biomed Mater. 2010;3:339–46. [PMC free article] [PubMed] [Google Scholar]
8. Joiner A. Tooth colour: A review of the literature. J Dent. 2004;32(Suppl 1):3–12. [PubMed] [Google Scholar]
9. Attin T, Manolakis A, Buchalla W, Hannig C. Influence of tea on intrinsic colour of previously bleached enamel. J Oral Rehabil. 2003;30:488–94. [PubMed] [Google Scholar]
10. Arvidson K, Johansson EG. Galvanic currents between dental alloys in vitro. Scand J Dent Res. 1985;93:467–73. [PubMed] [Google Scholar]
11. Ertaş E, Güler AU, Yücel AC, Köprülü H, Güler E. Color stability of resin composites after immersion in different drinks. Dent Mater J. 2006;25:371–6. [PubMed] [Google Scholar]
12. Reis RS, Neiva GF, Yaman P, Razzoog ME. Effect of firing on the color stability of a light-cured ceramic stain. J Prosthodont. 1996;5:182–5. [PubMed] [Google Scholar]
13. Braun A, Jepsen S, Krause F. Spectrophotometric and visual evaluation of vital tooth bleaching employing different carbamide peroxide concentrations. Dent Mater. 2007;23:165–9. [PubMed] [Google Scholar]
14. Attin T, Buchalla W, Gollner M, Hellwig E. Use of variable remineralization periods to improve the abrasion resistance of previously eroded enamel. Caries Res. 2000;34:48–52. [PubMed] [Google Scholar]
15. Prayitno S, Addy M. An in vitro study of factors affecting the development of staining associated with the use of chlorhexidine. J Periodontal Res. 1979;14:397–402. [PubMed] [Google Scholar]
16. Eriksen HM, Nordbø H. Extrinsic discoloration of teeth. J ClinPeriodontol. 1978;5:229–36. [PubMed] [Google Scholar]
17. Joiner A, Thakker G, Cooper Y. Evaluation of a 6% hydrogen peroxide tooth whitening gel on enamel and dentine microhardnessin vitro. J Dent. 2004;32(Suppl 1):27–34. [PubMed] [Google Scholar]
18. Maia E, Baratieri LN, Caldeira de Andrada MA, Monteiro S, Jr, Vieira LC. The influence of two home-applied bleaching agents on enamel microhardness: An in situ study. J Dent. 2008;36:2–7. [PubMed] [Google Scholar]
19. Jiang T, Ma X, Wang Z, Tong H, Hu J, Wang Y. Beneficial effects of hydroxyapatite on enamel subjected to 30% hydrogen peroxide. J Dent. 2008;36:907–14. [PubMed] [Google Scholar]
20. Hegedüs C, Bistey T, Flóra-Nagy E, Keszthelyi G, Jenei A. An atomic force microscopy study on the effect of bleaching agents on enamel surface. J Dent. 1999;27:509–15. [PubMed] [Google Scholar]
21. Arends J, Jongebloed WL, Goldberg M, Schuthof J. Interaction of urea and human enamel. Caries Res. 1984;18:17–24. [PubMed] [Google Scholar]
22. Arwill T, Myrberg N, Söremark R. Penetration of radioactive isotopes through enamel and dentine. II. Transfer of 22Na in fresh and chemically treated dental tissues. Odontol Revy. 1969;20:47–54. [PubMed] [Google Scholar]
23. Rotstein I, Dankner E, Goldman A, Heling I, Stabholz A, Zalkind M. Histochemical analysis of dental hard tissues following bleaching. J Endod. 1996;22:23–5. [PubMed] [Google Scholar]
24. Titley K, Torneck CD, Smith D. The effect of concentrated hydrogen peroxide solutions on the surface morphology of human tooth enamel. J Endod. 1988;14:69–74. [PubMed] [Google Scholar]
25. Prayitno S, Taylor L, Cadogan S, Addy M. An in vivo study of dietary factors in the aetiology of tooth staining associated with the use of chlorhexidine. J Periodontal Res. 1979;14:411–7. [PubMed] [Google Scholar]
26. Berger SB, Coelho AS, Oliveira VA, Cavalli V, Giannini M. Enamel susceptibility to red wine staining after 35% hydrogen peroxide bleaching. J Appl Oral Sci. 2008;16:201–4. [PMC free article] [PubMed] [Google Scholar]
27. Addy M, Prayitno S, Taylor L, Cadogan S. An in vitro study of the role of dietary factors in the aetiology of tooth staining associated with the use of chlorhexidine. J Periodontal Res. 1979;14:403–10. [PubMed] [Google Scholar]
28. Dietschi D, Rossier S, Krejci I. In vitro colorimetric evaluation of the efficacy of various bleaching methods and products. Quintessence Int. 2006;37:515–26. [PubMed] [Google Scholar]
29. Attia ML, Aguiar FH, Mathias P, Ambrosano GM, Fontes CM, Liporoni PC. The effect of coffee solution on tooth color during home bleaching applications. Am J Dent. 2009;22:175–9. [PubMed] [Google Scholar]
30. Côrtes G1, Pini NP, Lima DA, Liporoni PC, Munin E, Ambrosano GM, et al. Influence of coffee and red wine on tooth color during and after bleaching. ActaOdontolScand. 2013;71:1475–80. [PubMed] [Google Scholar]
31. Liporoni PC, Souto CM, Pazinatto RB, Cesar IC, de Rego MA, Mathias P, et al. Enamel susceptibility to coffee and red wine staining at different intervals elapsed from bleaching: Aphotoreflectance spectrophotometry analysis. Photomed Laser Surg. 2010;28(Suppl 2):S105–9. [PubMed] [Google Scholar]
32. Um CM, Ruyter IE. Staining of resin-based veneering materials with coffee and tea. Quintessence Int. 1991;22:377–86. [PubMed] [Google Scholar]
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