Article

Susceptibility to Coffee Staining during Enamel Remineralization Following the In-Office Bleaching Technique: An In Situ Assessment

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Abstract

PurposeTo assess in situ the enamel mineralization level and susceptibility to coffee staining after in-office bleaching.Materials and Methods Thirty-six human dental fragments assembled into intraoral devices were bleached with 35% hydrogen peroxide and treated as follows: (group 1) no contact with coffee; (group 2) immersion in a coffee solution for 30 minutes daily for 7 days, starting 1 week after bleaching; and (group 3) immersion in a coffee solution for 30 minutes daily for 14 days, starting immediately after bleaching. Enamel mineralization and color were assessed before bleaching (T1), immediately after bleaching (T2), and after 7 (T3) and 14 days (T4). The CIE whiteness index (W*) and closeness to white (ΔW*) following bleaching and/or immersion in coffee were calculated. Data were analyzed with Friedman and Wilcoxon tests or Kruskal–Wallis and Mann–Whitney U-tests (α = 0.05).ResultsSignificant differences in the mineralization levels were observed as a function of time. No significant differences in W* were observed between groups, nor was W* significantly different at T3 and T4. Similar ΔW* was observed between groups after 7 or 14 days.Conclusions The mineral loss after in-office bleaching was progressively reversed by contact with saliva for 14 days. The whiteness index was not affected by contact with coffee during the remineralization period.Clinical SignificanceThe results of this in situ study suggest that the mineral loss caused by in-office dental bleaching is minimal and is partly compensated by remineralization due to contact with saliva. Additionally, whiteness was not affected by daily exposition to coffee during the enamel remineralization, which indicates that avoiding the consumption of coffee immediately following in-office bleaching is unnecessary.

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... [2], [6], [10] However, saliva might not be able to completely restore calcium and phosphate baseline levels on bleached enamel. [11] Fluoride and other remineralizing solutions can favor a positive balance toward remineralization. [1], [4], [5], [12], [13] Sodium fluoride can minimize enamel demineralization, [14], [15] roughness, and other morphological alterations after tooth bleaching. ...
... Human saliva minimizes the demineralization induced by bleaching agents. [2], [11] In this study, the control group was artificial saliva with a neutral pH. Enamel remineralization with artificial saliva during consecutive bleaching sessions was effective in preventing staining. ...
... [24], [29], [30], [31] In dynamic models in situ with an everyday-contact with human saliva for 14 days after bleaching, it was found that natural saliva minimized the enamel morphological alterations, calcium loss and microhardness reduction expected with bleaching. [6], [11] Bleaching with 35% hydrogen peroxide induced adverse effects on the enamel that were reversed with a 7-day storage in artificial saliva after bleaching, [9] but it can change surface morphology only with 24 h. [31] Other authors found no difference in the mineral content analysis of teeth stored in artificial saliva for 4 weeks after bleaching compared to bleached teeth treated with fluoride for 5 min daily, followed by storage in artificial saliva. ...
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Background: The objectives were to evaluate the effect of surface treatments and waiting time before contact with dye on bleached enamel staining and surface treatments on roughness. Methods: One hundred bleached teeth were randomly assigned to G1 artificial saliva, G2 2% sodium fluoride (Flugel, Nova DFL), G3 casein phosphopeptide-amorphous calcium phosphate fluoride paste (MI Paste Plus, GC America), G4 rinse for bleached color maintenance (Keep White Rinse, DMC), and G5 polishing with impregnated disks (SuperBuff Disk, Shofu). Fifty specimens were immersed in coffee immediately after treatment; the others 1 h after. Color difference (ΔE) was evaluated with a spectrophotometer (Vita EasyShade) and roughness (Ra, Rq) with an optical profilometer (NewView 7300). Effects were analyzed with two-way ANOVA, Friedman, and Kruskal-Wallis test (P < 0.05). Results: Surface treatments (P = 0.878), waiting time (P = 0.105), and interaction (P = 0.145) were not significant to bleached color maintenance. Roughness was different among the evaluation time points (2nd evaluation >1st evaluation >3rd evaluation) (P < 0.001); not among surface treatments (G1, G2, G3, G4, G5) (P > 0.05). Conclusions: Surface treatments were similar to saliva for bleached enamel color maintenance. Immediate or 1-h postponed contact with coffee did not affect bleached enamel color. Bleaching increased enamel roughness; surface treatments and artificial saliva decreased it.
... 10,11 However, the length of time for dental bleaching may take 2-4 weeks, 6 depending on the gel concentration and technique 12 , which makes it difficult to restrict food/drinks containing dyes over a long period because food dyes are present in most foods consumed by many people daily. 13,14 Some authors claim that these dyes do not interfere with the effectiveness of dental bleaching, 5,[15][16][17] while other studies have found that bleached tooth enamel is more susceptible to staining by absorbing greater amounts of pigments, 18,19 as well as showing less stable results over time. 20 It is known that dental staining is not only related to the pH of substances but also to different kinds of dyes present in foods, as well as exposure time. ...
... 24 In reviewing the literature it was observed that several studies have tested various food and beverage containing dyes. [15][16][17][18][19]21,23 However, no studies were found that evaluated the effect of exposure to different natural and artificial dyes on bleached enamel. Consequently, the aim of this in vitro study was to evaluate the effectiveness of the dental bleaching of teeth exposed to natural (carmine, beet, and caramel) and artificial (red 40) dyes during bleaching treatment. ...
... 6,10,25 The gel used was 16% CP, which has proven efficiency, 15,25,26 and which contains remineralizing agents including potassium nitrate and sodium fluoride, which help to minimize changes in dental tissue. 26,27 The results are in agreement with previous literature studies , 5,15,17 which observed that dyes do not interfere with the effectiveness of dental bleaching. Some methodological aspects of this study may have supported our findings. ...
Article
Introduction: Bleached enamel surfaces may undergo changes and retain more dye, which is a reason to recommend the reduction/suspension of foods with dyes during dental bleaching. Aim: Evaluate the effects of the action of natural and artificial dyes on the bleached enamel of extracted human teeth. Materials and methods: Fifty human premolars were used, which were distributed in 5 groups (n = 10) according to the following staining solutions: GW (distilled water); GB (beet); Gca (caramel); GC (carmine); and GR (red 40). After the removal of the root and pulp section, the teeth were embedded in acrylic resin blocks, stored in artificial saliva, and kept at 37°C. At-home bleaching was performed using 16% carbamide peroxide (CP) for 3 hours daily for 3 weeks. After each daily session of bleaching, the specimens were exposed to the dye solution twice a day for 5 min; one of these exposures was performed immediately after bleaching. The color was recorded using a spectrophotometer according to the CIE Lab system (Δ E) for the following periods: baseline, during bleaching (after 1st, 2nd, and 3rd week) and post-bleaching (after 1 week and 1 month). The color was evaluated by two-way analysis of variance and Tukey's test (α=0.05). Results: There was effective dental bleaching for all groups: GW (18.5 ± 6.1), GB (19.9 ± 4.4), Gca (18.9 ± 6.1), GC (20.2 ± 4.6), and GR (19.3 ± 4.2), p <0.01. No color rebound was observed after 1 week and 1 month (p >0.05). Conclusion: The exposure to beet, carmine, caramel, and red 40 dyes did not interfere with the effectiveness of dental bleaching using 16% CP. Clinical significance: Dyes consumption during bleaching did not affect the effectiveness of dental bleaching.
... 18 Coffee and cola are listed as the leading solutions causing tooth staining. [19][20][21][22] This is because both solutions present pigments that are adsorbed or absorbed by the substrate 23 in addition to having low pH values that may potentiate dental staining: coffee is described as having a pH of about 5.5 24 and cola of about 2.6. 21 Some in vitro studies have evaluated the staining caused by coffee or cola associated with the bleaching treatment. ...
... When the device was removed from the oral cavity, it had to remain in a plastic box wrapped in damp gauze. 22 The device and the dental blocks had to be brushed twice a day with toothbrush and toothpaste, applied with 10 back-and-forth movements on top of each row. ...
... The enamel slabs were immersed into 30 mL of the coffee solution (considering a volume of 10 mL of solution per dental block) for 30 minutes daily, simulating the contact of the coffee with the dental structure for one day of consumption. 19,22 After immersion, the blocks were washed in distilled water for 10 seconds. The enamel slabs from column 2 were not submitted to any staining solution. ...
Article
The purpose of this in situ study was to evaluate the influence of staining solutions (coffee and cola) on the color change, microhardness, roughness, and micromorphology of the enamel surface during at-home and in-office dental bleaching. One hundred and thirty-five enamel bovine blocks were prepared to perform the evaluations. Fifteen volunteers used an intraoral appliance with nine enamel blocks for 15 days. The enamel blocks were randomly assigned among the different groups according to the three treatments: in-office bleaching with high hydrogen peroxide concentration (Opalescence Boost PF 40%, Ultradent) for 40 minutes in three sessions (first, eighth, and 15th days of treatment), at-home bleaching with low carbamide peroxide concentration (Opalescence PF 10%, Ultradent) for 60 minutes daily for 15 days, and a control group (no bleaching agent applied). The enamel blocks were immersed daily in different staining solutions (coffee or cola) for 30 minutes for 15 days or were not submitted to staining (control) to obtain a factorial scheme (3×3) of the dental bleaching treatment and staining solution (n=15). The microhardness analyses (Knoop), roughness evaluations (Ra), surface micromorphological observations, and color measurements (using the CIELAB system and the VITA Classical scale) were made before and after the bleaching treatments to assess immersion in staining solutions. Mixed model tests showed that there was a decrease in enamel microhardness after exposure to cola compared with coffee and the control group (p<0.0001) for both bleaching techniques. Roughness was higher for the cola groups (p<0.0001), and there was no significant difference between the coffee and the control groups. Generalized linear models showed that when no staining solution was applied, lighter color scores were found for the VITA Classical scale (p<0.0001). Without the staining solutions, there was an increase in luminosity (ΔL) (p=0.0444) for in-office bleaching. Lower values of Δa (p=0.0010) were observed when the staining solutions were not used. The Δb (p=0.3929) did not vary significantly between the bleaching agents, but when cola was applied, the values were significantly higher than for the control (p=0.0293). Higher values of ΔE (p=0.0089) were observed for in-office bleaching without staining solutions, while lower values of ΔE were observed for the in-office associated with coffee immersion. Regardless of whether being submitted to bleaching, the enamel stained with cola showed a decrease in microhardness, an increase in roughness, and changes in the micromorphology. The efficacy of the bleaching agents was greater when no staining solution (cola or coffee) was used, and in-office bleaching showed greater color change than the at-home bleaching technique.
... The specimens were randomly placed in the palatal devices (by drawing lots). 27 The pH characterization of each beverage was measured using a digital pH meter (Quimis, Diadema, SP, Brazil). The device was previously calibrated using deionized water at room temperature. ...
... Eight volunteers (4 men and 4 women) aged 20-30 years, who met the inclusion and exclusion criteria, as described in Table 1, participated in this study. 27 The volunteers were oriented to use the palatal device After the first 10 days period, the volunteers delivered the palatal devices, which were disinfected, and then the specimens were removed for the color stability and hardness measurements. Thereafter, the volunteers received another palatal device and specific beverages for the next 10 days. ...
... Inclusion and exclusion criteria for volunteer participation in this study27 ...
Article
Objective: To determine the color stability (CS) and hardness' decrease (HD) of two commercial resin-based composites (RBCs), after in situ staining conditions (SC). Methods: Six disc-shaped specimens (6 × 2 mm) of two RBCs-Filtek Z350 XT (FZX) and IPS Empress Direct (IED)-were randomly distributed into palatal devices. Eight volunteers (aged 20-30 years) participated in this study. The in situ SC consisted of 400 mL consumption (2 × 200 mL/day) of water, orange juice, cola soda, and coffee and 140 mL consumption of red wine, 10 days each. CS was obtained by CIELAB color difference (ΔE*) and HD (in %) by the Knoop method (50 g for 15 s), after curing (baseline) and after the in situ SC. Data were statistically analyzed at α = 0.05 significance level. Results: For both RBCs, the coffee (5.7 ± 0.5 for FZX; 5.9 ± 1.3 for IED) and red wine (6.1 ± 1.1 for FZX; 6.2 ± 1.6 for IED) groups showed the highest ΔE* while water the lowest (1.6 ± 0.6 for FZX; 1.8 ± 0.2 for IED). The highest HD was induced by red wine group for FZX (40.7 ± 5.4) and by cola soda for IED (40.6 ± 3.2) while the water groups (8.3 ± 1.7 for FZX; 7.8 ± 2.1 for IED) presented the lowest values for both RBCs. Conclusion: Both RBCs were affected by the in situ SC, but no significant differences for CS and HD were observed between them. Red wine and coffee showed higher discoloration potential. Clinical significance: This in situ study suggests that color stability and hardness' decrease of resin-based composites were dependent on the type of consumed beverage and materials' composition. Patients with esthetic direct restorations should be aware of the degradative potential of them.
... Office bleaching is a method applied by professionals to solve the discoloration of the teeth related to intrinsic and extrinsic factors [13][14][15]. This method generally uses high concentrations of hydrogen peroxide (HP) which is leading to the oxidation of the pigments present in enamel and dentin as a cause of its low molecular weight and free transit through the interprismatic spaces of enamel and throughout dentin [13][14][15]. ...
... Office bleaching is a method applied by professionals to solve the discoloration of the teeth related to intrinsic and extrinsic factors [13][14][15]. This method generally uses high concentrations of hydrogen peroxide (HP) which is leading to the oxidation of the pigments present in enamel and dentin as a cause of its low molecular weight and free transit through the interprismatic spaces of enamel and throughout dentin [13][14][15]. Although bleaching is accepted as an effective method and safe for hard tissues of teeth, it may not be safe for dental materials that have high erosive or degradation characteristics [16]. ...
... On the other hand, if TP gets closer to 0, it means increased opacity. In order to quantify the whiteness before and after bleaching, the whiteness index (WIC index) which was recommended by CIE was used [15]. The whiteness index value ( * ) is based on the distance of a color value from a nominal white point, represented in CIELAB color space as * = 100, * = 0, and * = 0, and defined according to the following equation: ...
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The aim of this study was to evaluate color stability of 3 restorative materials, discoloration ability of different solutions, efficacy of 2 office bleaching agents, and surface roughness and topography. Sixty specimens for Clearfil Majesty Esthetic (CME), Lava Ultimate (LU), and Vita Enamic (VE) were prepared. They were immersed into 3 staining solutions for 2 weeks and then they were bleached. According to the measured L⁎, a⁎, and b⁎ parameters described by CIELAB system, color changes (ΔE00), translucency parameters (TP), whiteness index values (W⁎), and changes in closeness to pure white (ΔW⁎) were calculated. Then 3 specimens from each group were scanned with an atomic force microscope for surface analysis. After staining, CME groups and control groups of LU and VE showed clinically acceptable color changes (ΔE00 < 1,8). After bleaching, while a reverse effect on color was observed, VE showed the furthest color values to pure white. There was no statistically significant difference between whiteness index values of LU and CME. LU was the most translucent material during the study and TP values of materials showed minimal differences. Most of the VE groups and a control group of LU showed surface roughness (R a ) values higher than critical value for biofilm accumulation (0,2 μm).
... Tooth whitening has become a popular procedure in cosmetic dentistry and is an effective and relatively safe esthetic treatment [8,9]. There are various tooth-bleaching products on the market, which are clinically divided into two types [10]. ...
... Bleaching agents were an effective method of stain removal and color recovery [13]. Previous research showed that tooth whitening significantly enhances people's self-confidence [14], and with an increasing desire for white teeth, the demand for tooth whitening and the use of tooth-bleaching products have increased [8,9]. ...
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Article
The aim of this study was to evaluate the effects of at-home and in-office bleaching agents on esthetic CAD-CAM materials after red wine immersion by measuring their optical properties. Sixty specimens were prepared out of three esthetic CAD-CAM materials: Vita Enamic, Celtra Duo, and Ceresmart (n = 20). All specimens were immersed in a red wine solution, and color measurements were performed. Specimens were randomly divided (n = 10) according to the bleaching procedure (in office, at home), bleaching durations were set to 3 time points, and color measurements were performed. According to the Commission Internationale de l’Eclairage (CIE) L* a* b* parameters, CIEDE2000 color differences (ΔE00), translucency parameters (TP00), and whiteness index values (ΔWID) after wine staining and after bleaching were calculated. Data were analyzed using the Mann–Whitney U-test, the Kruskal–Wallis test, and a two-way analysis of variance (ANOVA) (α = 0.05). ΔE00, ΔTP00, and ΔWID decreased with an increase in bleaching treatment. ΔE00 after the final bleaching treatment of in-office bleaching ranged from 1.7 to 2.0, whereas those of in-office treatment ranged from 0.4 to 1.1. All ΔTP00 and ΔWID after the final treatment were below the 50:50% perceptibility thresholds (ΔTP00 < 0.6, and ΔWID < 0.7). Significant differences in ΔE00, ΔTP00, and ΔWID among esthetic CAD-CAM materials were found between CD and CE. In the present study, color recovery after at-home and in-office bleaching appeared to be material-dependent. In-office bleaching showed more effective recovery comparing to at-home bleaching.
... Then, the portion was dissolved in 50 ml of boiling water, as suggested by the manufacturer, and agitated for about three minutes. Staining was performed by immersing the specimens in coffee for 15 minutes, considering this time was determined by the manufacturers who established it as the average time to drink a cup of coffee, and among coffee drinkers, to whom the average intake is 3.2 cups a day 21 . ...
... The color was analyzed with an objective method that promotes more reliable and accurate results, named spectrophotometry 22 , when compared to the results obtained with the visual method, thus preventing the interference of personal factors. Moreover, the bovine teeth used in the study were stored in artificial saliva, simulating the remineralization in the oral cavity 15,21 , which may reverse the erosion process and porosities caused by bleaching agents with low pH and oxidative ability. ...
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Introduction Considering the increased search for esthetic procedures, questions emerge about the maintenance and regression of color, especially regarding the need to restrict dark foods during bleaching procedures or their influence on the stability and effectiveness of the treatment. Objective To assess the influence of staining agents on tooth enamel during immediate bleaching treatment with 35% hydrogen peroxide. Material and method Sixty bovine teeth were divided into six groups (G) (n=10): G1: distilled water (control); G2: coffee; G3: cola soft drink; G4: wine; G5: mate tea; and G6: industrialized açaí. The samples were subjected to immediate bleaching using 35% hydrogen peroxide for 21 days (three applications of 15 minutes per session, every seven days) and pigment immersion between each session for 15 minutes. The color was assessed before starting bleaching and after 21 days, using a spectrophotometer. The data obtained were subjected to one-way ANOVA and heteroscedasticity analysis by the Welch and Brown-Forsythe tests. The Tamhane test was used for group comparison. Result The color change was visible to the naked eye, considering the mean ΔE in all groups tested was higher than 3.7. However, there was no statistical difference between the control group and the groups assessed. Conclusion The contact of staining agents on bovine tooth enamel did not affect the final result of the immediate tooth bleaching.
... Means and standard deviations of color change in shade guide units (DSGU) using the Bleach shade guide at the different assessment points along with the effect size (mean difference) and the 95% confidence interval (CI). Fortunately, based on two out of the three tools for color evaluation, this was not confirmed in this clinical study and in others [10,14,45]. An earlier study [14], reported that neither smoking habits nor coffee consumption jeopardized the whitening produced by at-home bleaching [10]. ...
... This was recently confirmed in a questionnaire-based study [44] in which the ingestion of different substances during bleaching was not found to be associated with a lower degree of whitening. Altogether, these findings suggest that the dentin substrate on which carbamide peroxide exerts its oxidizing action is probably similar irrespective of the smoking and dietary habits of the patient during the bleaching [10,14,45]. ...
... 29,48 Although the diode fluorescent device has been developed to detect enamel demineralization provided by caries, its application on bleached enamel was previously demonstrated. 49 There is no consensus in literature about the adverse effects of bleaching gels on tooth surface and the mechanism how the gels affect enamel structure. 9 The pH, concentration, saturation related to tooth mineral content, and oxidative capacity of the bleaching gels have been related to the demineralization potential of some products. ...
Article
Objective To compare at-home systems with reduced daily time of use (10% hydrogen peroxide [HP] gel with prefilled (PT) or customized trays (CT), and 10% carbamide peroxide [CP] gel), with the conventional nightguard vital bleaching (10% CP). Bleaching efficacy, adverse effects, and patient's satisfaction were evaluated. Methods Sixty participants were randomly divided into treatments (14 days): Opalescence GO (OGO)-10%HP PT-30 min, White Class-10%HP CT-30 min, Opalescence PF-10%CP CT-2 h, and Opalescence PF-10%CP CT-8 h. Color difference (visual and spectrophotometer), tooth sensitivity (visual analogue scale), gingival condition (Löe index), enamel mineralization (laser fluorescence), and patients' satisfaction (questionnaire) were assessed. Statistical tests were applied (5%). Results After 1 year, color difference was similar for the groups (p > 0.05). All groups showed similar sensitivity risk (p > 0.05). The intensity of sensitivity and gingival irritation was mild for all gels, but higher for OGO. Fluorescence after bleaching remained similar to those of sound enamel. All participants were satisfied with treatments. Conclusions All systems produced similar bleaching efficacy, which was maintained after 1 year. Patients were satisfied with bleaching outcomes. Tooth sensitivity occurred in all groups, but with overall mild intensity. No relevant gingival irritation and enamel demineralization was observed.
... Não foi utilizada fonte de luz, pois as evidências científicas atuais mostram que seu emprego não melhora o efeito clareador (MARAN et al., 2019). Não foi recomendado à paciente evitar o consumo de alimentos e bebidas com corantes, pois os trabalhos clínicos mais recentes não encontraram relação entre seu consumo e a qualidade final do tratamento clareador (REZENDE et al., 2013;MATIS et al., 2015;MORI et al., 2016). ...
Article
Um dos maiores desafios da odontologia minimamente invasiva é o reestabelecimento restaurador de tecidos dentais perdidos ao mesmo tempo em que se preserva ao máximo os substratos sadios, sem realizar desgastes adicionais em esmalte e dentina hígidos. Dentre os procedimentos odontológicos estéticos, o clareamento dental é um dos mais requisitados pelos pacientes insatisfeitos com a aparência do seu sorriso. Isto ocorre devido a sua eficácia, baixa invasividade e simplicidade da técnica. Após a realização do procedimento, se faz necessário a substituição das restaurações pré-existentes em razão do aspecto não harmônico resultante. Este trabalho tem como objetivo relatar um caso clínico de tratamento estético anterior em que os anseios estéticos da paciente foram resolvidos sob uma ótica conservadora, minimante invasiva com clareamento dental (técnica associada) e restaurações tipo Classe III e IV em resina composta. Para que o tratamento tenha sucesso, todas as etapas clínicas são de suma importância e, neste caso, as expectativas do paciente foram alcançadas por meio de uma abordagem conservadora e com alta previsibilidade.
... The results of this study agree with other studies that verified no pigment action during tooth bleaching 1,10,12,20 . The contact of the bleached tooth enamel with coffee did not affect the bleaching of specimens, thus the recommendation for a white diet so that enamel is less susceptible to pigmentation becomes unnecessary. ...
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Article
Introduction Obtaining the result expected during tooth bleaching requires a correct diagnosis of the type of staining presented. The causes of tooth staining differ depending on the etiological factor. Objective To assess the color change caused by the immersion of bovine teeth in coffee solution during at-home tooth bleaching using a 16% carbamide peroxide gel. Material and method Thirty-three sound bovine teeth were assigned to three groups of eleven teeth each: 1 – Teeth bleached (TB) four hours per day for 21 days; 2 – TB four hours per day for 21 days and immersed in coffee solution immediately after tooth bleaching; 3 – TB four hours per day for 21 days and immersed in coffee solution four hours after the end of tooth bleaching. Immersed in coffee was performed for 15 minutes and tooth color was assessed before the start of the bleaching procedure and after 21 days with an intraoral spectrophotometer. Test Shapiro-Wilk was used to assess homoscedasticity and data were submitted to one-factor Analysis of Variance (ANOVA) and Tukey’s test (p <0.05). Result The color change observed in group 1 (5.76 ± 2.74)A was not statistically different from group 2 (8.83 ±5.11)A, which was immersed in coffee solution immediately after tooth bleaching, and from group 3, which was immersed in coffee solution four hours after tooth bleaching (8.20 ±3.71)A. Conclusion Coffee did not interfere with the tooth bleaching results, regardless of the time after the procedure. Hence, diet restrictions are not necessary during tooth bleaching.
... Immersion of bovine enamel samples in red wine for 48 hours, either immediately, 24 hours, or one week after whitening with 35% HP exhibited similar levels of stain uptake regardless of the time frame separating whitening and staining treatments [175]. Additionally, an in-situ study where small enamel slabs were mounted in intra oral devices and whitened using 35% HP and then stained either immediately or 7 days after whitening, showed no significant differences in enamel whiteness indices after being exposed to coffee [176]. ...
Article
Objectives To provide a narrative review on vital dental whitening chemistry, toxicity and safety, vital dental whitening techniques, whitening systems, potential side effects of whitening and cyclic whitening using products with a range of concentrations and pH values. In addition, new developments and recommendations in the field of vital dental whitening will be presented to help clinicians understand the whitening process, its advantages, limitations, and the impact of whitening concentration and pH on enamel providing guidance in tailoring whitening treatments. Data Data were gathered using the following keywords: dental whitening, roughness, hardness, sensitivity, hydrogen peroxide, whitening pH, whitening concentration, whitening chemistry, colour, and toxicity. Sources An electronic search was performed using PubMed and Scopus databases. Bibliographic material from papers reviewed was then used to find other relevant publications. Conclusions The effectiveness of vital dental whitening depends on many factors, such as the concentration/pH of the whitening agent, application duration, chemical additives, and re-mineralising agents used. Developing new whitening products and technologies such as nano-additives and alternative carrier systems is showing promising results, and might prove efficient in maximising whitening benefits by accelerating the whitening reaction and/or minimising expected reversible/irreversible enamel structural damage.
... Mori et. al. 112 reported the whitening effect of tooth bleaching with 35% hydrogen peroxide on coffee stained tooth. The whitening index the authors used was the same as the W* calculated in this study. ...
... Moreover, it has been reported that pigment-rich solutions result in increased total and extrinsic discolouration of bleached teeth [21]. Nevertheless, in an in situ study, tooth fragments were bleached with 35 % hydrogen peroxide (HP) intraorally and then immersed in a coffee solution immediately after bleaching [22]. The results indicated that avoiding coffee consumption after in-office bleaching is unnecessary, in agreement with previous in vitro studies [23,24]. ...
Article
Objectives To evaluate the short-term effects of stain-causing beverages on the effectiveness of in-office tooth bleaching. Methods Participants were recruited and randomly divided into 3 groups based on beverages used for rinsing during and after the bleaching procedure: group N (tap water, control group), group C (coffee), and group T (tea). Participants were instructed to rinse with the respective solutions for 30 s, 4 times daily for 4 weeks. All participants received two in-office bleaching treatment sessions with 40% hydrogen peroxide (Opalescence BOOST PF 40%, Ultradent); the sessions were separated by a 1-week interval. Tooth colour was assessed using a spectrophotometer (Easyshade, Vita ZahnFabrik) before the bleaching procedure (T0), immediately after the first session of bleaching (T1), immediately after the second session of bleaching (T2), as well as one week (T3) and three weeks after (T4) the end of bleaching. Tooth sensitivity (TS) was ranked using a numerical rating scale (NRS) and a visual analogue scale (VAS) at different time points. Results No significant difference in the whiteness index (W), △E, △a* and △b* values among the 3 groups was observed at any time interval (P for all > 0.05). At T4, the △L* value in group C was significantly lower than that in groups T and N (P = 0.022 and P = 0.001, respectively), though no significant difference in △L* values was observed among the 3 groups at T1 (P = 0.402), T2 (P = 0.643) and T3 (P = 0.177). Additionally, no significant difference was found in the TS values among the 3 groups at any of the evaluation time points (P for all > 0.05). Conclusions Exposure to coffee or tea during the bleaching treatment period did not affect the effectiveness of the treatment. However, exposure to coffee after the bleaching treatment did affect the effectiveness of the treatment. Exposure to stain-causing beverages did not affect the bleaching-induced TS (ClinicalTrials.gov Identifier: NCT03933527). Clinical Significance The consumption of coffee or tea during tooth bleaching may not interfere with the colour change produced by the treatment. However, clinicians should advise their patients to refrain from, at least to some extent, consuming coffee after the bleaching procedure to maintain the effectiveness of the treatment.
... Bleached enamel stains more than non bleached when in contact with a dying beverage and this discolouration is more evident right after bleaching treatment; the dyes absorption by the enamel treated with Whiteness HP Maxx is smaller after 1 week than immediately after bleaching [15]. However, considering the daily exposure to coffee during enamel remineralization after bleaching, other authors suggest that avoiding coffee consumption immediately after bleaching is not necessary [14]. ...
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This study goal is to present a case report of tooth bleaching treatment with the combination of the custom tray and in-office techniques, and to discuss about the considerations for result maintenance. A treatment approach was planned involving exogenous bleaching with custom trays with 7.5% hydrogen peroxide, and in-office bleaching with 35% hydrogen peroxide. The in-office bleaching agent was applied in two 15-minute applications, without led light. The patient was instructed to use the custom trays only a day after, with one drop of the bleaching agent for each tooth space. After the application of the bleaching agent, the patient used the trays for 1 hour per day, continuously for 30 days, 15 days for each arch. Considering the executed treatment approach, we may conclude that when correctly indicated, tooth bleaching with the combination of the in-office and custom trays techniques can be an acceptable choice of treatment, capable of enhancing the smile esthetics with a simple technique that preserves the sound dental structure. The patient should be instructed for the maximum color preservation and esthetic result maintenance, and should be advised that retreatments may become necessary depending on the oral hygiene and frequence of coloured food and drinks intake.
... This shows the violet light treatment alone allowed recovery of 29.4% of the original fluorescence intensity using 445 nm excitation. Previous studies investigating the effects of coffee staining monitor changes in mineralization levels by using the DIAGNOdent® system 72 , and in parameters extracted from colorimetry or reflectance measurements 72,73 . Then, our result is not comparable with other studies. ...
... Some researchers did not consider coffee to be a potent staining solution compared to wine for example [31,32]. However, as the consumption of wine is not widespread in Middle Eastern communities, the effect of other staining agents including coffee becomes more importance. ...
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Objective: To investigate the effect of Arabic coffee on bleached teeth in comparison to black coffee. Material and Methods: Forty teeth (sound maxillary or mandibular premolars with no carious lesions) were randomly selected into 4 groups (A, B, C and D). One group (A) did not receive bleaching and was incubated in saline. The second group (B) was bleached and then incubated in saline. The last two groups were bleached and were immersed in either Arabic coffee (C) or black coffee (D). Color recording of the samples was always carried out as near to their mid-buccal surfaces as possible using VITA Easyshade Advance System. Color measurements were carried out using a digital spectrophotometer at baseline and after short-term and long-term immersion. Data were subjected to two way ANOVA and T-test. The level of significance was set at was set at 0.05. Results: Results show that immersion in Arabic coffee resulted only in significant reduction in the b* color value upon long-term immersion (i.e. a reduction in the yellow hue). Black coffee on the other hand resulted in significant: reduction in lightness, increased red tint and increased yellow hue altogether. Conclusion: The use of Arabic coffee did not deteriorate color, with the only significant change being the reduction of yellowish hue. Arabic coffee could be an alternative to black coffee after bleaching.
... These results were opposed by other studies such as a study conducted by Mori et al. [34] who observed the effect of coffee on bleached enamel and concluded that coffee had no effect on the bleaching effect. ...
... Immersion of bovine enamel samples in red wine for 48 h, either immediately, 24 h, or one week after whitening with 35 % HP exhibited similar levels of stain uptake regardless of the time frame separating whitening and staining treatments [175]. Additionally, an in-situ study where small enamel slabs were mounted in intra oral devices and whitened using 35 % HP and then stained either immediately or 7 days after whitening, showed no significant differences in enamel whiteness indices after being exposed to coffee [176]. ...
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Background and Objectives White spot lesions (WSLs) are a common problem that can be conservatively managed by resin infiltration. Consumption of dark beverages such as coffee causes staining of dental hard tissues, which can deteriorate the esthetic qualities of treated WSLs. The aims of this study were to investigate the effect of dark coffee heavy consumption on ICON ® resin infiltrated WSLs and the influence of bleaching on them after staining. Methods Twenty surfaces from sound human extracted third molars were used in the study. Two square-shaped buccal and lingual window areas had artificially created WSLs (received buccal resin infiltration afterward). Using VITA Easyshade, the baseline Δ E was recorded. Espresso coffee was used to immerse all surfaces for 8 days. The color coordinates according to CIE LAB were recorded for all surfaces at 2, 4, 6, and 8 days of immersion, and Δ E was calculated at each timepoint. After 8 days, in-office bleaching was applied to all surfaces according to the manufacturer’s instructions and the color. Coordinates and Δ E were recorded. For statistical analysis, an independent sample t -test was used to compare each group. A general linear mixed model (GLMM) repeated measure ANOVA was applied for statistical analysis of L * and changes due to staining over time. Results Analysis of time as a main effect on the L values of surfaces was statistically highly significant ( p < 0.01). The interaction of time with surfaces under investigation and type of surface (test vs. control) as a main effect were non-significant ( p = 0.47 and p = 0.35, respectively). Bleaching showed a significant difference in color lightness in both test and control surfaces compared to the mean L value at 8 days of staining ( p < 0.01). Conclusion Capsule-coffee consumption gradually influences the esthetic of resin infiltration on treated teeth. However, bleaching materials might restore an esthetic shade.
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O clareamento dental tem sido uma opção conservadora para o tratamento estético dos dentes. A procura pelo procedimento tornou-se popular, sendo considerado ainda um procedimento minimamente invasivo, seguro e eficaz quando feito corretamente e acompanhado por um profissional habilitado. Esse procedimento poderá mudar significativamente a aparência dos dentes, tornando-a agradável. O propósito deste estudo foi avaliar o efeito do clareamento de consultório do esmalte dental sobre sua alteração de cor e a rugosidade superficial após o envelhecimento artificial embebidas fitness. 100 dentes bovinos foram submetidos a uma análise cromática inicial, por meio de um Espectrofotômetro de Reflexão Ultravioleta Visível*,Modelo* VITA Easyshade® Compact, com a avaliação de cor calculada através do Sistema CIE L*a*b*. A análise de rugosidade superficial (Ra) dos blocos de esmalte foi realizada em rugosímetro HommelEtamic W10 (JENOPTIK Industrial Metrology Germany GmbH). Após as análises iniciais os dentes foram divididos em10 grupos de estudo (n=10)- 50 amostras clareadas e 50 amostras não clareadas (3sessões-1/semana)-sendo imersas em sucos detox de açai (DTXAc), rosa (DTXRs), verde (DTXV), amarelo (DTXAm) e água mineral(A) por 1 hora/ dia. A alteração de cor (ΔE) e rugosidade (Ra) foram calculados.Não foi observada diferença estatisticamente significante na porcentagem de aumento da rugosidade das amostras. Apresentaram maior alteração de cor, as amostras clareadas que foram submetidas a envelhecimento artificial em DTXAm e DTXRs. Entre os grupos que não foram clareados, os Sucos DTXRs, de DTXAc e DTXV apresentaram maior alteração de cor. O uso de Sucos DTXRs e DTXAm entre as sessões de clareamento de consultório resultou em maior alteração de cor.Descritores: Esmalte Dentário; Clareamento Dental; Clareadores Dentários.ReferênciasAttia ML, Gomes ACO, César ICR, Munin E, Aguiar FHB, Liporoni PCS. Avaliação da eficácia de clareamento e da susceptibilidade ao manchamento de blocos dentais humanos e bovinos submetidos a dois agentes pigmentantes. In: Anais do IX Encontro Latino Americano de Iniciação Científica e V Encontro Latino Americano de Pós-Graduação. João Pessoa: Universidade do Vale do Paraíba; 2005.Ramos APB, Cesar ICR, Alves GL, Alves LP, Munin E, Rego MA, Liporoni PC. Avaliação do clareamento dental com peróxido de carbamida a 16%, submetidos a diferentes pigmentos, através de análise de fotorreflectância e rugosidade. In: Anais do X Encontro Latino Americano de Iniciação Científica e VI Encontro Latino Americano de Pós-Graduação – Universidade do Vale do Paraíba. João Pessoa: Universidade do Vale do Paraíba; 2005.Souto CMC. Avaliação da influência de ingestão de bebidas corantes em diferentes tempos na estabilidade do clareamento dental: análise de fotorreflectância. [dissertação]. Taubaté: Universidade de Taubaté; 2006.Sundfeld RH. Clareamento de Dentes Vitais com Peróxido de Carbamida. Araçatuba: Unesp, 2013. Disponível em: http://www.foa.unesp.br/include/ arquivos/foa/restauradora/files/capitulo-clareamento-de-dentes-vitais-com-peroxido-de-carbmida.pdfAraújo LS, Santos PH, Anchieta RB, Catelan A, Fraga Briso AL, Fraga Zaze AC, Sundfeld RH. Mineral loss and color change of enamel after bleaching and staining solutions combination. J Biomed Opt. 2013;18(10):108004-6.Anaraki SN, Shahabi S, Chiniforush N, Nokhbatolfoghahaei H, Assadian H, Yousefi B. Evaluation of the effects of conventional versus laser bleaching techniques on enamel microroughness. Lasers Med Sci. 2015;30(3):1013-18.Esberard RR, Consolaro A, Esberard RM, Bonetti I, Esberard RR.Efeitos das técnicas e dos agentes clareadores externos na morfologia da junção amelocementária e nos tecidos dentários que a compõem. Rev Dental Press Estét. 2004;1(1):58-72.Rezende M, Cerqueira RR, Loguercio AD, Reis A, Kossatz S. 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Dent Mater. 2001;17(1):87-94Da Cunha FB, Rodrigues e Silva BH, Freitas De Paula BL, Alencar CM, de Albuquerque Jassé FF, Silva CM. Effect of high concentrated fluoride-based dentifrice on the hardness, roughness, and color of the bleached enamel. J Conserv Dent. 2018;21(4):433-37.Carlos NR, Pinto A, Amaral FD, França F, Turssi CP, Basting RT. Influence of staining solutions on color change and enamel surface properties during at-home and in-office dental bleaching: an in situ study. Oper Dent. 2019;44(6):595-608.Attia ML, Cavalli V, do Espírito Santo AM, Martin AA, D'Arce MB, Aguiar FH et al. Effects of bleaching agents combined with regular and whitening toothpastes on surface roughness and mineral content of enamel. Photomed Laser Surg. 2015;33(7):378-83.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: a photoreflectance spectrophotometry analysis. 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Peroxide bleaching agent effects on enamel surface microhardness, roughness and morphology. Braz Oral Res. 2004;18(4):306-11.Potocnik I, Kosec L, Gaspersic D. Effect of 10% carbamide peroxide bleaching gel on enamel microhardness, microstructure, and mineral content. J Endod. 2000;26(4):203-6.Torres CR, Koga AF, Borges AB. The effects of anti-oxidant agents as neutralizers of bleaching agents on enamel bond strength. Braz J Oral Sci. 2006;5(16):971-76.Rezende M, Loguercio AD, Reis A, Kossatz. Clinical Effects of exposure to coffe during at-home vital bleaching. Oper Dent. 2013;38(6):E229-36.Mori AA, Lima FF, Benetti AR, Terada RS, Fujimaki M, Pascotto RC. Susceptibility to coffee staining during enamel remineralization following the in-office bleaching technique: an in situ assessment. J Esthet Restor Dent. 2015;28(Suppl 1):23-31.Azer SS, Hague AL, Johnston WM. Effect of pH on tooth discoloration from food colorant in vitro. 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Pigments of food and beverages could affect dental bleaching efficacy. The aim of this investigation was to evaluate color change and mineral loss of tooth enamel as well as the influence of staining solutions normally used by adolescent patients undergoing home bleaching. Initial hardness and baseline color were measured on enamel blocks. Specimens were divided into five groups (n=5): G1 (control) specimens were kept in artificial saliva throughout the experiment (3 weeks); G2 enamel was exposed to 10% carbamide peroxide for 6 h daily, and after this period, the teeth were cleaned and stored in artificial saliva until the next bleaching session; and G3, G4, and G5 received the same treatments as G2, but after bleaching, they were stored for 1 h in cola soft drink, melted chocolate, or red wine, respectively. Mineral loss was obtained by the percentage of hardness reduction, and color change was determined by the difference between the data obtained before and after treatments. Data were subjected to analysis of variance and Fisher's test (α=0.05). G3 and G5 showed higher mineral loss (92.96±5.50 and 94.46±1.00, respectively) compared to the other groups (p≤0.05). G5 showed high-color change (9.34±2.90), whereas G1 presented lower color change (2.22±0.44) (p≤0.05). Acidic drinks cause mineral loss of the enamel, which could modify the surface and reduce staining resistance after bleaching.
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This study evaluated in vitro and in situ the potential adverse effects of 10% carbamide peroxide on human enamel using microhardness, calcium loss and surface morphology analysis. Twenty-four enamel slices (4 mm2) were obtained from recently extracted premolars. The specimens were polished under water-cooling down to 1,200-grade sandpaper. After initial microhardness readings (100 g), the specimens were randomly divided into two groups for in situ and in vitro conditions. The specimens were covered with 10% carbamide peroxide for eight hours. After removing the bleaching gel, the in vitro specimens were stored in deionized water and the in situ specimens, included in an intra-oral appliance, were placed in the oral cavity of four volunteers. These cycling sequences took place for 14 days. Upon conclusion of the bleaching treatment, new microhardness readings were performed on all specimens. Calcium dosage was assessed from the bleaching gel collected after initial exposure on day one, then from gel collected between days two and seven and gel collected between day eight and 14 using an atomic absorption spectrophotometer. Surface morphology was observed from two non-treated control specimens and two specimens of each experimental bleached group under SEM evaluation. Statistical analysis (ANOVA and Tukey tests) disclosed that specimens bleached in situ showed similar microhardness to unbleached specimens and had statistically higher (p < 0.01) hardness than in vitro bleached specimens. The loss of calcium in the in vitro situation at 14 days was 2.5 times higher than the in situ condition. SEM micrographs demonstrated that surface alterations were more pronounced in the in vitro condition. The adverse effects of carbamide peroxide on enamel were evident in specimens bleached in vitro but were not seen in situ. The presence of saliva could prevent the demineralizing effect of bleaching gel in situ.
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SUMMARY The purpose of the present study was to evaluate whether exposure to coffee during bleaching treatment with 16% carbamide peroxide (CP) affects the degree of whitening and tooth sensitivity. Forty patients with central incisors darker than A2 were selected. Participants who did not drink coffee were assigned to the control group (CG), while participants who drink coffee at least twice a day were assigned to the experimental group (EG). For CG, foods with dyes were restricted. For EG there was no restriction on food and patients were asked to make coffee rinses for 30 seconds, four times daily. For both groups 16% CP was used for a period of three hours daily for three weeks. Shade evaluation was assessed visually by Vita classical shade guide and by the Easyshade spectrophotometer at baseline, during bleaching (first, second, and third weeks), and postbleaching (one week and one month). Patients recorded their sensitivity perceptions by means of the numerical rating scale and 0-10 visual analog scales. Variation in shade guide units and the two colors (ΔE) were evaluated by two-way analysis of variance and Tukey tests (α=0.05). Absolute risk of tooth sensitivity and intensity of tooth sensitivity was evaluated by Fisher exact and Mann-Whitney tests (α=0.05). Effective bleaching was observed for both groups after three weeks, without statistical difference. No difference in terms of risk of tooth sensitivity and intensity of tooth sensitivity was detected between groups. Approximately 57% of the participants experienced tooth sensitivity, which was recorded mainly as "mild." Exposure to coffee during bleaching treatment does not seem to affect the degree of bleaching and tooth sensitivity.
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This study aimed to investigate bleached enamel susceptibility to coffee and red-wine staining at different time periods after bleaching. Although hydrogen peroxide is effective for dental bleaching, little is known regarding color stability immediately after bleaching. Fifty-four standardized bovine enamel slabs were obtained and assigned to the following treatments (n = 9): (CO) control: sound enamel surface submitted only to bleaching with 35% hydrogen peroxide (HP); (C30') enamel submitted to HP and coffee immersion at 30 min after bleaching; (C150') enamel submitted to HP and coffee immersion at 150 min after bleaching; (W30') enamel submitted to HP and red-wine immersion at 30 min after bleaching; and (W150') enamel submitted to HP and red-wine immersion at 150 min after bleaching. The color of treated enamel was determined by means of photoreflectance spectroscopy at baseline (T(0)) and after the described treatments (T(f)), and data were statistically analyzed with ANOVA and Tukey tests (p < 0.05). No differences were observed between the exposure times of 30 and 150 min after bleaching for both beverages (p > 0.05). Although coffee did not stain the surface, red wine significantly darkened previously bleached enamel (p < 0.05). Bleached enamel was susceptible to red-wine staining at both 30 and 150 min after bleaching procedures, whereas coffee did not interfere with the bleaching process.
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Colour modification of tooth enamel has proven successful, but it is unclear how various bleaching applications affect micro-structural integrity of the whitened enamel. To investigate the internal structural integrity of human intact tooth enamel with the application of two commonly used whitening regimes (in-office power bleaching with 35% hydrogen peroxide and home bleaching with 10% carbamide peroxide), evaluations were performed on teeth of identical colour classification. After the bleaching applications, the enamel mineral density was quantified and visualised with micro-computed tomography. The micro-structural differences between the whitened tooth enamel samples were distinctive, though the colour parameter changes within the samples were equivalent. Home bleaching achieved colour modification by demineralisation, whereas in-office bleaching depended on redistribution of the minerals after treatment and subsequent enhanced mineralisation.
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To evaluate the colour regression of bleached teeth in four experimental environments, and to explore the relationship between colour change and bulk miners loss. Forty freshly extracted sound human incisors were in vitro treated using an in-office bleaching gel containing 38% hydroxide carbamide. The bleached teeth were subsequently divided into four groups and stored in four different environments: purified water, artificial saliva, a commercial remineralisation gel, and a desiccator. A spectrophotometer and a mu-CT were used to investigate the colour parameters (L*, a*, and b*) and the mineral content of the teeth pre- and post-bleaching. ANOVA and Tukey's post hoc analysis were performed to investigate the effect of time on the colour coordinates. Paired t-tests were used to compare the mineral content changes. Linear regression test was performed to explore the relationship of the colour coordinates and mineral content change in the colour regression process. Colour regression occurred in the mineral containing environment accompanying with the mineral content remarkable increase in the outer layers of teeth tissue (P<0.05). No colour regression and mineral content change were found in the anhydrous environment (P>0.05). The regression of lightness is significantly correlated with the density change of teeth hard-tissue (P<0.001, r=0.611). In this in-office bleaching system, the colour regression is mainly resulted by the reversal of lightness, and is correlated with the presence of the remineralisation processes within the teeth tissue.
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To quantify the change in color of human and bovine teeth exposed to a coffee solution during a 16% carbamide peroxide (16% CP) home application bleaching treatment using photoreflectance analysis. 40 enamel slabs (4 x 4 x 2 mm) were obtained from seven unerupted third human molars and seven bovine incisors, which were allocated into four groups: G1: human control group whitened and not exposed to a coffee solution; G2: bovine control group whitened and not exposed to a coffee solution; G3: human teeth whitened and exposed to a coffee solution; G4: bovine teeth whitened and exposed to a coffee solution. The home bleaching procedure was performed using 16% CP gel applied in a 1 mm-thick layer on the tooth surface over a period of 6 hours per day, for 28 days. Tooth color was evaluated using photoreflectance analysis throughout the bleaching procedure at intervals of 7, 14, 21 and 28 days, and posttreatment at 7, 15 and 30 days. Results were statistically analyzed using ANOVA and Tukey-Kramer tests. After 28 days of bleaching treatment, no significant difference was detected between photoreflectance analysis of specimens exposed to coffee solution and specimens not exposed to coffee solution (P < 0.05). However, when the teeth were exposed to a coffee solution during home bleaching treatment, the whitening effect was observed to be less stable (P < 0.05). Bovine and human enamel substrates behaved similarly in terms of staining and bleaching effects, although they presented inherent differences in color (P < 0.05).
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To determine the susceptibility of teeth to darken after bleaching with 35% hydrogen peroxide and 16%carbamideperoxide. Thirty-eight premolars were covered with varnish and the mesiobuccal facets polished up to 0.04 microm, leaving a flat surface. Thirty-six of these premolars were then randomly assigned to 3 groups and the shade of the polished surfaces recorded using a Vita shade guide set in a value disposition. According to the manufacturers'instructions, 12 samples were bleached with 35% hydrogen peroxide (in-office group) and 12 samples with 16%carbamide peroxide (at-home group). The 12 samples in the control group were not bleached. Two days later, the shades of the bleached teeth were recorded; all samples were immersed in silver nitrate 50% for 4 hours,rinsed, and fixed (using a dithioxamidesolution) for 24 hours. Polished surfaces were cleaned and the samples' shade recorded and analyzed using ANOVA. The remaining 2 premolars were bleached the same as those in the test group and analyzed using atomic force microscopy. The mean shade values were 6.2, 3.7, and 10.9 for in-office samples; 8.8, 1.7, and 6.1 for at-home samples; and 7.8 and 9.4 for the control group. After pigmentation, the at-home group had a lighter shade than the in-office group (P=or<.001). Atomic force microscopy showed no significant surface differences. While all the samples were susceptible to pigmentation, this tendency was greater following application of 35% hydrogen peroxide
Article
To report the use of Quantitative Light-induced Fluorescence (QLF) to determine if there was a tendency for bleached enamel to take up extrinsic stains more than unbleached enamel. Bovine teeth devoid of stains were selected, the roots removed and enamel gently pumiced. Each tooth was sectioned into two and each half randomly assigned to two groups (bleached or unbleached). Windows were created on each half using clear acid resistant varnish. 38% Hydrogen peroxide gel was applied to the exposed windows of the bleached group for 1 hour. The teeth were rinsed and dried. Bleached and unbleached halves of the same teeth were then mounted on glass rods attached to pot lids using green stick. QLF images were taken. The teeth were subjected to a cycle of artificial saliva, chlorhexidine and tea (2 minutes in each solution). This was repeated 5 times. QLF images were taken at the end of each cycle. The uptake and progression of stain was detected in all the sections by QLF. Using paired t- test (SPSS) there was no significant difference between the two groups for the change from baseline to the final stain cycle (p > 0.05), however there was variability in stain uptake within the groups as the cycles progressed. Bleaching of enamel in vitro does not appear to increase the susceptibility of enamel to extrinsic staining.
Article
A comparative study of synthetic and natural apatite has been made by means of high-resolution transmission electron microscopy, with the aim of elucidating structural differences between the two materials. Natural dental apatite is distinguished by the presence of mineral-deficient zones, which are likely centers for artificial etchant attack. The nature of these zones has been examined by the technique of preferential heavy-metal staining. This technique, in conjunction with the standard interpretation of lattice-image contrast, leads to the conclusion that these are naturally occurring calcium-deficient zones and are not the result of either beam damage or mechanical defect.
Article
To evaluate the clinical response of a low peroxide concentration bleaching system with a desensitizing agent relative to a marketed control. After balancing for baseline color and age, 34 healthy adult volunteers were randomized to one of two marketed bleaching systems, 5% carbamide peroxide bleaching gel + potassium nitrate in a custom tray (Colgate Platinum Gentle Plus) or 6.0% hydrogen peroxide bleaching strips (Crest Whitestrips). Daily contact time was 6-8 hours for the tray system compared to 1 hour for the strip system, following manufacturers' instructions. Whitening was measured objectively using digital image analysis to assess L*a*b* after 7 days, while tolerability was assessed through interview and examination. The predominantly female (85%) and non-smoking (91%) study population ranged from 20-47 years of age. Both treatments yielded a statistically significant (P < 0.001) whitening benefit with respect to reduction in yellowness (Ab*) and improvements in other color endpoints (deltaL*, deltaE*, and a new parameter, deltaW*) compared to baseline. The strip group experienced greater color improvement on average for all color parameters in the study. After 7 days treatment, the adjusted mean deltab* was -1.24 in the strip group and -0.65 in the tray group, with these groups differing significantly (P = 0.04). Tooth sensitivity was reported by 13% of subjects using the hydrogen peroxide strips, compared to 22% of subjects using the carbamiide peroxide potassium nitrate tray system. No subjects discontinued treatment early due to an adverse event.
Article
Several vital bleaching systems have been introduced in response to the demand in esthetic dentistry. The active agents are commonly hydrogen peroxide or carbamide peroxide used in at-home or in-office techniques. Although generally positive results have been reported concerning the whitening ability of these agents, concerns still remain as to their effects on dental tissues. The purpose of this investigation was to evaluate the effect of these bleaching agents on the enamel surface morphology. Twelve extracted teeth were used according to three experimental protocols. In experimental protocol 1, specimens were treated with 35% hydrogen peroxide. In experimental protocol 2, after treatment with 35% hydrogen peroxide the specimens were immersed in natural saliva for 1 week. In experimental protocol 3, 35% hydrogen peroxide was applied once and 10% carbamide peroxide was applied for 1 week (12 h of 10% carbamide peroxide alternating with 12 h saliva). Scanning electron microscopy evaluation revealed that regional variation in tooth morphology surface sometimes exceeded the effects of the peroxide used according to experimental protocols. Thirty-five percent hydrogen peroxide had a tendency to promote an increase in density of pits. Precipitates were observed on specimen surfaces immersed in natural saliva according to protocol 2. A smooth and shiny surface was observed in specimens treated according to protocol 3. The potential relationship between surface alterations and differences in enamel permeability is currently under investigation.
Article
To develop and evaluate a reproducible intrinsic discolouration model in vitro, based on tea, which would allow the effectiveness of bleaching to be evaluated. The crown portions of extracted human third molars were sectioned bucco-lingually in half. Colour assessments were made at baseline, post staining and post whitening using a standard clinical shade guide (SG), a shade vision clinical colorimeter system (SVS) and a reflectance chromometer. Internal staining employed a standard tea solution into which groups of five specimens were placed from 1 to 6 days. All assessments demonstrated maximum staining within one day. Groups of stained specimens were exposed to 1. Water (placebo control) 2. Enamel polished 3. Enamel polished and bleached through enamel 4. Bleached through enamel 5. Bleached through dentine 6. Bleached through enamel and dentine 7. Exposed to the bleach vehicle (minus active control). Control and bleach gel treatments were for 30 min. Comparisons of treatment effects were made using unpaired t-test on groups selected a priori for analysis. SG and SVS revealed that control and polish treatments had no or little effect respectively on tooth shade but all bleach treatments produced marked and statistically significant whitening effects and to a similar magnitude. Bleaching treatments returned the majority of specimens to the original shade or beyond representing a SG mean change of 13.8-15 shade guide units (SGU). Chromometer readings were consistent except that polishing alone increased tooth lightness slightly. Teeth were reproducibly stained internally, to provide a model in vitro by which to evaluate bleaching. The model, could be used to study many aspects of vital tooth bleaching, but has the limitation, without in vivo or in situ data, of cautiously extrapolating the effects in vitro to outcome clinically.
Article
Tooth whitening is one of the fastest growing areas in cosmetic and restorative dentistry. An increasing number of patients are demanding faster ways to bleach their teeth. Therefore, clinicians are being pushed to seek quicker and easier means to bleach their patients' teeth, while maintaining safety in bleaching procedures. The authors included in the clinical trial 10 subjects 18 years of age or older, each of whom had six caries-free maxillary anterior teeth without restorations on the labial surfaces and no tooth sensitivity. For each subject, one-half of the maxillary arch received a 35 percent hydrogen peroxide (Group 1) gel application for 30 minutes, and the other one-half of the maxillary arch received a 38 percent hydrogen peroxide (Group 2) gel application for 30 minutes. The in-office bleaching treatment was maintained and reinforced using a 10 percent carbamide peroxide at-home bleaching agent for 60 minutes. Subjects repeated both the in-office and take-home bleaching treatments for three consecutive days. The shade change was 8.5 for Group 1 and 9 for Group 2. There was no statistically significant difference between the two groups (P = .3434). An average shade rebound of two shades was recorded at seven days for both treatment systems. No sensitivity was reported during or after the bleaching treatment. When combined with 10 percent carbamide peroxide at-home applications, use of the Group 1 and Group 2 bleaching materials resulted in significant tooth lightening. By using the clinical technique presented, clinicians can reduce the time required to complete tooth-whitening treatment. Using the correct tray design and improved chemical formulations of tooth whiteners may reduce gingival and tooth sensitivity, thus increasing safety.
Article
There is still some controversy in the dental literature whether carbamide peroxide bleaching causes demineralization of teeth. One of the reasons for this controversy is that there is as yet no reliable, non-destructive in vitro method for assessing mineral loss in bleached teeth. The objective of this study was to investigate the possible demineralization effect of 10% carbamide peroxide bleaching agent on enamel and dentine non-destructively. microCT images were obtained of 12 human molar tooth sections. These sections had 10% carbamide peroxide applied for eight hours a day over a period of 15 days. Further tomographic images were obtained and the mineral content prior to and post bleaching assessed. A total of 144 regions were evaluated using the image processing language available in the work station. The application of 10% carbamide peroxide was found to cause demineralization of the enamel extended to a depth of 50 microm below the enamel surface (Paired t-test, p<0.05). This study confirmed that microCT was indeed a highly suitable method for assessing mineral content of dental enamel after bleach application. It is recommended that application of bleaching agents should be carefully considered in patients susceptible to caries and tooth wear.
Article
The aim of this 'in situ' study was to evaluate the microhardness of dental enamel following treatment with an in-office and an at-home vital bleaching agent through a novel approach using samples temporarily bonded 'in vivo'. Human dental enamel slabs (n=88) were subjected to sequential polishing and initial Knoop microhardness tests were performed. The slabs were fixed to the facial surfaces of the maxillary first molars of 44 human volunteers. They were divided into four groups (n=11) according to the treatment group: G1- in-office-CP37+ at-home-CP10; G2- in-office-CP37+ at-home-PLA; G3- in-office-PLA and at-home-CP10; G4- in-office and at-home-PLA. After 3 weeks of treatment, final microhardness measurements were performed. ANOVA and Tukey's HSD hoc analysis (alpha=0.05) revealed no differences among initial or final microhardness values (p>0.05); however, significant differences occurred between initial and final values for each group (p<0.01), The evaluation of microhardness revealed a reduction of 6.8% for G1, 4.1% for G2, 3.4% for G3 and 3.5% for G4. In-office bleaching with 37% carbamide peroxide, an at-home bleaching with 10% carbamide peroxide, and a combination of both resulted in lower enamel microhardness when measured immediately post-treatment. However, long-term effects of these treatments are not known, and are believed to be clinically insignificant due to the relatively small reductions observed in enamel microhardness. Interestingly, the carrier, Cabopol 934P, also resulted in similar reduction in enamel microhardness even when administrated alone as a placebo.
Article
Tooth whitening has become one of the most popular dental treatments available. This article compares the efficacy of 2 in-office whitening systems using a split-arch, randomized, parallel, blinded clinical evaluation study. Both in-office tooth whitening systems were effective and there was no significant statistical difference over the 2-week period of observation. The use of light did not demonstrate any benefit over the chemically activated tooth whitening system after a 2-week recall.
Article
The objective of this in vitro study was to investigate whether a high concentration 'in-office' bleaching agent affected the mineral content of enamel and dentin. A commercially available 35% carbamide peroxide bleaching agent was applied for 2h to sectioned teeth (n=11). Specimens were then immersed in artificial saliva at 37 degrees C for a further 24h to simulate the oral environment. Tomographic images of these sections were obtained (micro-CT 80, Scanco, Switzerland) prior to and post-bleach application. Eight three-dimensional regions of interest (ROI), starting from the enamel surface extending to the dentinoenamel junction, were selected for each section. The hydroxyapatite equivalent mineral concentrations (g/cm(3)) of the ROIs were calculated. Any changes in mineral content as a consequence of the bleaching procedure were calculated in relation to each ROI. There was a significant reduction in the mineral content of enamel specimens post-bleach application extending to a depth of 250microm (paired t-test, p<0.05); this reduction in mineral content was greatest in the ROI's closest to the tooth surface. There was, however, no significant difference in the mineral content of dentin as a consequence of bleaching. This in vitro study has shown that significant demineralization of enamel occurred following bleaching with 35% carbamide peroxide. The concept that 'in-office' bleaching is a non-destructive cosmetic procedure should be reconsidered.
Article
To evaluate enamel permeability after external bleaching procedures. The coronal portion of 75 human canines were covered with an acid resistant varnish, except for a 7.1 mm2 circular area on the labial surface and, according to a randomized complete block design, specimens were allocated to bleaching treatments using carbamide peroxide-containing agents (CP): 10%, 16% or 37%; or a 35% hydrogen peroxide product (HP). The control group was exposed to artificial saliva. The bleaching agents were applied following the manufacturer's recommendations over 21 days. In between bleaching exposures, specimens were stored in artificial saliva. Samples were then prepared according to a histochemical coloring method based on copper sulfate and dithiooxamide solutions. Digital images captured in an optical microscope were used to measure the percentage of copper ion penetration over the total enamel thickness on three sections taken from the exposed area. Analysis of Deviance showed a significant difference for the permeability values among groups (P = 0.046). Likelihood ratio test revealed that the use of the CP10% and HP35% agents caused significantly greater enamel permeability than did the control treatment. No significant differences in percentage of copper ion penetration were found among CP10%, CP16%, CP37% and HP35%. This in vitro study demonstrated that depending on the external bleaching procedure, enamel permeability may be increased.
Article
The aim of the present study was to determine the alteration in human enamel after hydrogen peroxide treatment using FT-IR spectroscopy. It is hypothesized that infrared spectroscopy is capable of showing alterations in human enamel after peroxide treatment and the alteration in enamel is proportional to peroxide concentration. The effects of 10, 20 and 30% hydrogen peroxide solutions on human enamel were tested. Thirty non-carious human teeth, extracted for periodontal reasons, were used in this study. They were divided into 3 groups of 10, according to the peroxide concentration, sectioned, and the specimens were embedded in resin for infrared spectroscopic analysis. The total treatment time was 120 min. Spectra of the specimens were taken before treatment and 30, 60 and 120 min after it. Another spectrum was taken in a week. Infrared spectroscopic analysis showed two distinct bands (biological PO(4)nu1 and nu2) that were capable of describing the alterations in enamel structure. On comparing the infrared spectra of non-treated and treated specimens, structural changes were detected in the superficial enamel. The alteration in enamel was proportional to treatment time and hydrogen peroxide concentration. Higher concentration and longer treatment time resulted in more severe alterations. The numerical analysis of the spectra revealed that on using concentrated hydrogen peroxide solutions the alterations of the IR spectra were more pronounced. The spectra taken in 1 week after treatment did not show spontaneous reversibility in enamel structure. At-home and in-office peroxide-containing bleaching agents are capable of causing alteration in enamel at low and high concentrations as well. According to the results of this study it is recommended to perform tooth whitening using low concentration of hydrogen and/or carbamide peroxide, and shorten treatment time to reduce the possible destruction but reach the required change in color.
Article
Recently, vital bleaching by carbamide peroxide has become more popular; therefore, it is necessary to study the effect of this agent on enamel and dentin. The purpose of this study was to evaluate the effect of a 16 percent carbamide peroxide bleaching gel, Vivastyle, on enamel staining susceptibility. Thirty bovine specimens were selected and randomly divided into two groups of 15. The experimental group was subjected to Vivastyle gel and then was immersed in coffee for half an hour daily for three weeks. The control group was only immersed in coffee. The teeth were evaluated using a colorimeter to measure L*, a*, b* of each tooth. Value (black to white) is denoted as L*, wheres chroma (a* b*) is denoted as red (+a*), green (_a*), yellow (+b*), and blue (_b*). Total color differences between two colors (deltaE) were calculated using the following formula: deltaE = [(deltaL*)2 + (deltaa*)2+(deltab*)2]: deltaE1.Bleached, AE2: bleached and immersed in coffee, deltaE3: immersed in coffee. Mean differences were: deltaE1 = 9.478, deltaE2 = 13.808 and deltaE3 = 7.230. Paired comparison by use of Duncan test showed there was a significant difference between deltaE1 and deltaE2 (P0.000); and t test showed there was no significant difference between deltaE3 and deltaE1. (P0.08 > 0.05), but deltaE3 showed a significant difference with deltaE2(P0.000). After vital bleaching, the enamel staining susceptibility significantly increased.
Enamel susceptibility to coffee and red wine staining at different intervals elapsed from bleaching: a photoreflectance spectrophotometry analysis
  • Pcs Liporoni
  • Cmc Souto
  • R B Pazinatto
Liporoni PCS, Souto CMC, Pazinatto RB, et al. Enamel susceptibility to coffee and red wine staining at different intervals elapsed from bleaching: a photoreflectance spectrophotometry analysis. Photomed Laser Surg 2010;28:105-9.