Influence of pH on the Effectiveness of Hydrogen Peroxide Whitening

2014 ◽  
Vol 39 (6) ◽  
pp. E261-E268 ◽  
Author(s):  
CRG Torres ◽  
E Crastechini ◽  
FA Feitosa ◽  
CR Pucci ◽  
AB Borges
Keyword(s):  
Hydrogen Peroxide ◽  
Red Wine ◽  
Alcoholic Solution ◽  
Bleaching Effect ◽  
Significance Level ◽  
Peroxide Bleaching ◽  
Color Changes ◽  
Ph Values ◽  
Naoh Solution ◽  
Influence Of Ph

SUMMARY Objective To evaluate the influence of pH on the bleaching effect of hydrogen peroxide on chromogen agents. Method Hydrogen peroxide 50% was mixed with red wine or with an alcoholic solution of tobacco in glass cuvettes, resulting in final peroxide concentrations of 16.97% and 21.12%, respectively. The pH of this mixture was measured and adjusted with 3.3 M HCl solution or 2.5 M NaOH solution to obtain the final pH values of 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, and 9.0. After mixing, the color of these solutions was evaluated in a reflectance spectrophotometer; readings were repeated after 10 minutes for the wine solution and 20 minutes for the tobacco solution. Ten samples were prepared for each solution at each pH. Color changes (Delta E) were calculated. The data were statistically analyzed using analysis of variance one-way and Tukey tests, with a significance level of 5%. Results There were significant differences among the different pH values for the wine and tobacco solutions (p=0.0001). The Tukey test showed that for both solutions, pH 9.0 resulted in a significantly greater bleaching effect than the other values tested. Conclusion The efficacy of hydrogen peroxide bleaching is directly proportional to the increase in its pH.

Effects of pH Values of Hydrogen Peroxide Bleaching Agents on Enamel Surface Properties

2011 ◽  
Vol 36 (5) ◽  
pp. 554-562 ◽  
Author(s):  
B Xu ◽  
Q Li ◽  
Y Wang
Keyword(s):  
Hydrogen Peroxide ◽  
Chemical Composition ◽  
Ph Value ◽  
Negative Control ◽  
Enamel Surface ◽  
Control Group ◽  
Solution Ph ◽  
Peroxide Bleaching ◽  
Color Changes ◽  
Ph Values

SUMMARY This study investigated the influence of pH values of bleaching agents on the properties of the enamel surface. Sixty freshly extracted premolars were embedded in epoxy resin and mesiodistally sectioned through the buccal aspect into two parts. The sectioned slabs were distributed among six groups (n=10) and treated using different solutions. Group HCl was treated with HCl solution (pH=3.0) and served as a positive control. Group DW, stored in distilled water (pH=7.0), served as a negative control. Four treatment groups were treated using 30% hydrogen peroxide solutions with different pH values: group HP3 (pH=3.0), group HP5 (pH=5.0), group HP7 (pH=7.0), and group HP8 (pH=8.0). The buccal slabs were subjected to spectrophotometric evaluations. Scanning electron microscopy investigation and Micro-Raman spectroscopy were used to evaluate enamel surface morphological and chemical composition alterations. pH value has a significant influence on the color changes after bleaching (p<0.001). Tukey's multiple comparisons revealed that the order of color changes was HP8, HP7>HP5, HP3>HCl>DW. No obvious morphological alterations were detected on the enamel surface in groups DW, HP7, and HP8. The enamel surface of groups HCl and HP3 showed significant alterations with an erosion appearance. No obvious chemical composition changes were detected with respect to Micro-Raman analysis. Within the limitations of this study, it was concluded that no obvious morphological or chemical composition alterations of enamel surface were detected in the neutral or alkaline bleaching solutions. Bleaching solutions with lower pH values could result in more significant erosion of enamel, which represented a slight whitening effect.

Effectiveness of In-office Hydrogen Peroxide With Two Different Protocols: A Two-center Randomized Clinical Trial

2018 ◽  
Vol 43 (4) ◽  
pp. 353-361 ◽  
Author(s):  
IEB Martins ◽  
S Onofre ◽  
N Franco ◽  
LM Martins ◽  
A Montenegro ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Color Change ◽  
Absolute Risk ◽  
Rank Test ◽  
Bleaching Agent ◽  
Tooth Sensitivity ◽  
Peroxide Bleaching ◽  
Color Changes ◽  
Ph Values ◽  
The Absolute

SUMMARY Objectives: The aim of this study was to compare the bleaching efficacy and tooth sensitivity (TS) of a 38% hydrogen peroxide bleaching agent used for in-office bleaching, applied under different time protocols: a 40-minute application or two 20-minute applications. Methods and Materials: Forty-four patients from Brazil and Colombia, with right superior canines darker than C2, were selected for this multicenter, single-blind, randomized trial. The teeth were bleached in two sessions, with a one-week interval between them, in a split-mouth design. The bleaching agent was applied in two 20-minute (2×20) applications or one 40-minute (1×40) application in each session according to the manufacturer's instructions. The color changes were evaluated by using subjective (Vita Classical and Vita Bleachedguide) and objective (Easyshade Spectrophotometer) methods at baseline and 30 days after the second session. Tooth sensitivity was recorded up to 48 hours with a 0-10 visual analog scale. Also, the pH values during the application of bleaching were recorded. Color change in shade guide units and ΔE were analyzed by using the Student t-test (α=0.05). The absolute risk and intensity of TS were evaluated with the McNemar test, the Wilcoxon signed-rank test, and the Friedman test, respectively (α= 0.05). Results: Significant whitening was observed in both groups after 30 days of clinical evaluation. The use of a 40-minute application did not significantly influence the absolute risk of TS (68%, 95% confidence interval [CI] = 53-80) as well as the intensity of TS compared with the acid bleaching gel (absolute risk of 82%, 95% CI = 68-91). The pH values did not differ significantly between groups and at the different assessment periods (p=0.42). Conclusion: The use of a 40-minute in-office bleaching agent gel application produced the same whitening degree and TS that the two 20-minute bleaching agent applications did. The former preferably should be applied because one 40-minute application does not require gel refreshing.

Influence of Hydrogen Peroxide Bleaching Gels on Color, Opacity, and Fluorescence of Composite Resins

2012 ◽  
Vol 37 (5) ◽  
pp. 526-531 ◽  
Author(s):  
CRG Torres ◽  
CF Ribeiro ◽  
E Bresciani ◽  
AB Borges
Keyword(s):  
Hydrogen Peroxide ◽  
Composite Resin ◽  
Color Change ◽  
Composite Resins ◽  
Control Group ◽  
Peroxide Bleaching ◽  
Color Changes ◽  
Tukey Test ◽  
Bleaching Gels ◽  
Bleaching Treatment

SUMMARY The aim of the present study was to evaluate the effect of 20% and 35% hydrogen peroxide bleaching gels on the color, opacity, and fluorescence of composite resins. Seven composite resin brands were tested and 30 specimens, 3-mm in diameter and 2-mm thick, of each material were fabricated, for a total of 210 specimens. The specimens of each tested material were divided into three subgroups (n=10) according to the bleaching therapy tested: 20% hydrogen peroxide gel, 35% hydroxide peroxide gel, and the control group. The baseline color, opacity, and fluorescence were assessed by spectrophotometry. Four 30-minute bleaching gel applications, two hours in total, were performed. The control group did not receive bleaching treatment and was stored in deionized water. Final assessments were performed, and data were analyzed by two-way analysis of variance and Tukey tests (p<0.05). Color changes were significant for different tested bleaching therapies (p<0.0001), with the greatest color change observed for 35% hydrogen peroxide gel. No difference in opacity was detected for all analyzed parameters. Fluorescence changes were influenced by composite resin brand (p<0.0001) and bleaching therapy (p=0.0016) used. No significant differences in fluorescence between different bleaching gel concentrations were detected by Tukey test. The greatest fluorescence alteration was detected on the brand Z350. It was concluded that 35% hydrogen peroxide bleaching gel generated the greatest color change among all evaluated materials. No statistical opacity changes were detected for all tested variables, and significant fluorescence changes were dependent on the material and bleaching therapy, regardless of the gel concentration.

scholarly journals A comparative analysis of in-office vital 6% hydrogen peroxide activated charcoal tooth whitening treatment enhanced with an 810nm diode laser, compared to 35% hydrogen peroxide bleaching

2021 ◽  
Vol 76 (2) ◽  
pp. 64-71
Author(s):  
Shabeer I Hassim ◽  
Tufayl A Muslim
Keyword(s):  
Hydrogen Peroxide ◽  
Diode Laser ◽  
Activated Charcoal ◽  
Research Question ◽  
Treatment Protocol ◽  
Primary Data ◽  
Absorption Enhancement ◽  
Significance Level ◽  
Peroxide Bleaching ◽  
Bleaching Procedure

Laser dental bleaching is considered to be a contemporary approach to enhancing the in-office power bleaching procedure. Objective Investigate if laser enhanced 6% Hydrogen Peroxide (HP) solution is equivalent to 35% HP solution over a two-visit power bleaching treatment protocol. In a randomised double-blinded clinical trial, 43 patients were assigned to a group that received either the laser-enhanced 6% Hydrogen Peroxide (n=21) treatment, or the standard 35% Hydrogen Peroxide (n=22) treatment, over two visits, with a one-week interval. Activated charcoal HP paste was prepared for both groups. The laser enhanced 6% HP group received a dosage of 90 J/cm² per bleaching cycle using 810nm diode laser. Tooth colour was measured at the beginning and end of each session registering parameters L*, a* and b*, and tooth sensitivity. The calculated difference between these Parameters, ∆E, was the primary data focus. The mean ∆E over the treatment duration was used to answer the research question by a t-test to evaluate group differences at 5% significance level. The analysis revealed that the null hypothesis could not be rejected and the results were inconclusive. The observations expound the idea of an absorption enhancement mechanism, rather than a free radical activation, as the technique for improving bleaching outcomes.

scholarly journals Influence of pH Value of Bleaching Gels on Surface Roughness of Bovine Enamel

2019 ◽  
pp. 311-321
Author(s):  
Jocelyn G. Lugo-Varillas DDS ◽  
Pedro L. Tinedo-López DDS,MSc ◽  
Gustavo Watanabe Oshiro DDS,MSc ◽  
Alberth Correa Medina DDS,MSc,PhD ◽  
Evelyn Álvarez Vidigal DDS,MSc,PhD ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Surface Roughness ◽  
Ph Value ◽  
Tooth Enamel ◽  
Wilcoxon Test ◽  
Peroxide Bleaching ◽  
Ph Values ◽  
Bovine Enamel ◽  
Spearman Test ◽  
Bleaching Gels

Objective: The purpose of this study was to evaluate the influence of the pH levels of three in-office bleaching gels on the surface roughness of bovine enamel, after the bleaching protocol. Materials and methods: 36 samples of bovine enamel were obtained, which were cut and divided into three groups (n=12): 40%hydrogen peroxide (Opalescence Boost40%), 35% hydrogen peroxide (Whiteness HP AutoMixx) and 35% hydrogen peroxide (Whiteness HP Blue), receiving a 40-minute application of bleaching. The average pH values were determined using a pH meter during the initial and final application of the gel. A roughness meter was used to assess surface roughness (Ra) before and after bleaching. Data were analyzed with the Friedmann and wilcoxon test (difference between groups); the Kruskall Wallis and U Mann test (difference in each group), as well as Pearson or Spearman test for correlation. Results: There is an increase in pH values from the beginning to the end of bleaching in all groups, except for the 35% hydrogen peroxide group (Whiteness HP Automixx). For surface roughness results there is an increase in all groups. No correlation was found between pH values of the bleaching gels and the surface roughness of the enamel after bleaching. Conclusions: Hydrogen peroxide bleaching gels with high concentrations that have a high or low pH could cause alterations in the surface of the tooth enamel, such as increase in surface roughness.

scholarly journals Enamel susceptibility to red wine staining after 35% hydrogen peroxide bleaching

2008 ◽  
Vol 16 (3) ◽  
pp. 201-204 ◽  
Author(s):  
Sandrine Bittencourt Berger ◽  
Alessandra Sanchez Coelho ◽  
Valéria Aparecida Pessatti Oliveira ◽  
Vanessa Cavalli ◽  
Marcelo Giannini
Keyword(s):  
Hydrogen Peroxide ◽  
Red Wine ◽  
Peroxide Bleaching

scholarly journals Effects of pre-operative air-powder polishing and rubber-cup prophylaxis on tooth bleaching : Randomized controlled split-mouth clinical study

2020 ◽  
Author(s):  
zeliha gonca bek kurklu ◽  
mustafa ozcan
Keyword(s):  
Hydrogen Peroxide ◽  
Similar Efficacy ◽  
Tooth Bleaching ◽  
Bleaching Agent ◽  
Color Parameters ◽  
Peroxide Bleaching ◽  
Color Changes ◽  
Randomized Controlled ◽  
Assessment Period ◽  
Bleaching Treatment

Abstract Background: The aim the study to compare the effects of pre-operative air-powder polishing and rubber-cup prophylaxis on tooth bleaching Methods: 23 subjects suffering from discoloration, were enrolled in a randomized controlled split mouth experimental study. Before bleaching, air powder polishing (APP) and rubber-cup polishing (RCP) techniques were applied on either side of the mouth. A 40% hydrogen peroxide bleaching agent applied two 15-minute applications for in-office bleaching. The tooth bleaching effects assessed immediately after and 1 week. Results: There were no significant differences between prophylaxis groups with respect to all color parameters (ΔL, Δa, Δb, ΔEab, ΔE00 and ΔSGU) at immediate period (p>0,05). At 1 week assessment period there were no significant differences between prophylaxis groups with respect to all color parameters (p>0,05) except delta E00 (p<0,05). Conclusions: Two prophylaxis techniques produced similar efficacy in bleaching treatment and the APP technique produced higher levels of color changes.

scholarly journals In vitro studies of temperature and pH influence on chlorophyll degradation by horseradish peroxidase: Spectroscopic and HPLC studies

2014 ◽  
Vol 68 (2) ◽  
pp. 233-239 ◽  
Author(s):  
Sanja Petrovic ◽  
Sasa Savic ◽  
Dejan Markovic ◽  
Zivomir Petronijevic
Keyword(s):  
Hydrogen Peroxide ◽  
Horseradish Peroxidase ◽  
Chlorophyll A ◽  
Hplc Analysis ◽  
Ph Values ◽  
Ph Influence ◽  
Main Degradation Product ◽  
Different Temperatures ◽  
Influence Of Ph

In vitro chlorophyll a degradation by horseradish peroxidase in the presence of the resorcinol was investigated in this work, and the influence of pH and temperature was particularly studied. Chlorophyll a degradation was followed by UV-VIS and HPLC. Chlorophyll a was degraded when hydrogen peroxide was added into reaction mixture containing chlorophyll fraction, horseradish peroxidase, resorcinol and phosphate buffer. HPLC analysis has identified the main degradation product of chlorophyll a as 132 -hydroxychlorophyll a. The degradation was traced at different temperatures and pH values. The increasing temperatures led to increase of chlorophyll a degradation, with a maximum at 37 ?C. The degradation also increased with increasing pH values, reaching maximum at pH 6.

The role of copper ions in hydrogen peroxide bleaching: Their origin, removal, and effect on pulp quality

TAPPI Journal ◽  
2012 ◽  
Vol 11 (7) ◽  
pp. 37-46 ◽  
Author(s):  
PEDRO E.G. LOUREIRO ◽  
SANDRINE DUARTE ◽  
DMITRY V. EVTUGUIN ◽  
M. GRAÇA V.S. CARVALHO
Keyword(s):  
Hydrogen Peroxide ◽  
Copper Ions ◽  
Peroxide Bleaching ◽  
Metals Removal ◽  
Peroxide Decomposition ◽  
Equipment Corrosion ◽  
And Performance ◽  
And Control ◽  
Main Effects

This study puts particular emphasis on the role of copper ions in the performance of hydrogen peroxide bleaching (P-stage). Owing to their variable levels across the bleaching line due to washing filtrates, bleaching reagents, and equipment corrosion, these ions can play a major role in hydrogen peroxide decomposition and be detrimental to polysaccharide integrity. In this study, a Cu-contaminated D0(EOP)D1 prebleached pulp was subjected to an acidic washing (A-stage) or chelation (Q-stage) before the alkaline P-stage. The objective was to understand the isolated and combined role of copper ions in peroxide bleaching performance. By applying an experimental design, it was possible to identify the main effects of the pretreatment variables on the extent of metals removal and performance of the P-stage. The acid treatment was unsuccessful in terms of complete copper removal, magnesium preservation, and control of hydrogen peroxide consumption in the following P-stage. Increasing reaction temperature and time of the acidic A-stage improved the brightness stability of the D0(EOP)D1AP bleached pulp. The optimum conditions for chelation pretreatment to maximize the brightness gains obtained in the subsequent P-stage with the lowest peroxide consumption were 0.4% diethylenetriaminepentaacetic acid (DTPA), 80ºC, and 4.5 pH.

Effect of Different Dentifrices, Bleaching with 35% Hydrogen Peroxide, and Red Wine on Surface Color and Roughness of Bovine Enamel

2020 ◽  
Vol 02 ◽  
Author(s):  
RM Garcia ◽  
WF Vieira-Junior ◽  
JD Theobaldo ◽  
NIP Pini ◽  
GM Ambrosano ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Generalized Linear Models ◽  
Repeated Measures ◽  
Red Wine ◽  
Linear Models ◽  
Artificial Saliva ◽  
Surface Color ◽  
Dental Bleaching ◽  
Surface Alteration ◽  
Bovine Enamel

Objective: To evaluate color and roughness of bovine enamel exposed to dentifrices, dental bleaching with 35% hydrogen peroxide (HP), and erosion/staining by red wine. Methods: Bovine enamel blocks were exposed to: artificial saliva (control), Oral-B Pro-Health (stannous fluoride with sodium fluoride, SF), Sensodyne Repair & Protect (bioactive glass, BG), Colgate Pro-Relief (arginine and calcium carbonate, AR), or Chitodent (chitosan, CHI). After toothpaste exposure, half (n=12) of the samples were bleached (35% HP), and the other half were not (n=12). The color (CIE L*a* b*, ΔE), surface roughness (Ra), and scanning electron microscopy were evaluated. Color and roughness were assessed at baseline, post-dentifrice and/or -dental bleaching, and after red wine. The data were subjected to analysis of variance (ANOVA) (ΔE) for repeated measures (Ra), followed by Tukey ́s test. The L*, a*, and b* values were analyzed by generalized linear models (a=0.05). Results: The HP promoted an increase in Ra values; however, the SF, BG, and AR did not enable this alteration. After red wine, all groups apart from SF (unbleached) showed increases in Ra values; SF and AR promoted decreases in L* values; AR demonstrated higher ΔE values, differing from the control; and CHI decreased the L* variation in the unbleached group. Conclusion: Dentifrices did not interfere with bleaching efficacy of 35% HP. However, dentifrices acted as a preventive agent against surface alteration from dental bleaching (BG, SF, and AR) or red wine (SF). Dentifrices can decrease (CHI) or increase (AR and SF) staining by red wine.

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