scholarly journals Dynamic Model of Hydrogen Peroxide Diffusion Kinetics into the Pulp Cavity

2012 ◽  
Vol 13 (4) ◽  
pp. 440-445 ◽  
Author(s):  
So Ran Kwon ◽  
Li Yiming ◽  
Udochukwu Oyoyo ◽  
Raydolfo M Aprecio
Keyword(s):  
Hydrogen Peroxide ◽  
Dynamic Model ◽  
Time Course ◽  
Color Change ◽  
Color Measurement ◽  
Control Group ◽  
Diffusion Kinetics ◽  
Peroxide Bleaching ◽  
Pulp Cavity ◽  
Color Measurements

ABSTRACT Aim To measure the time course hydrogen peroxide penetration into the pulp cavity and evaluate short-term tooth color changes after bleaching. Materials and methods Twenty extracted human canines were sectioned, pulp tissue removed and the cavity enlarged. Teeth were painted with nail varnish to leave a 6-mm diameter circle on the buccal surface. Baseline color was measured spectrophotometrically. Teeth were randomized into a control group (n = 10) treated with 30 μl of glycerin base and a bleaching group (n = 10) exposed to 30 μl of 40% hydrogen peroxide for 1 hour. A linear low density polyethylene wrap was placed to prevent evaporation of the material. Acetate buffer was placed into the cavity and replenished every 10 minutes and placed into plastic tubes. Hydrogen peroxide amount was estimated spectrophotometrically using leukocrystal violet and horseradish peroxidase. Specimen color was remeasured immediately after bleaching, 1 hour, 1 day 1, 2 and 6 weeks postbleaching. Color change was measured per Commission Internationale de l'Eclairage methodology. Mann-Whitney procedure was used to assess baseline color measurements and total hydrogen peroxide penetration amount. Friedman's test was used to assess within group differences for color change and hydrogen peroxide penetration. Results There was significantly greater hydrogen peroxide penetration in the bleaching group (p < 0.05). Hydrogen peroxide penetration levels were constant throughout the 1-hour evaluation period in the bleaching group. The groups showed no difference at baseline with respect to any of L*a*b color measurements (p > 0.05). The postbleaching color measurement showed an increase of change in overall color (ΔE) and lightness (ΔL) up to 1 week followed by a gradual stabilization up to 6 weeks. Conclusion This dynamic model provided information about the time course diffusion kinetics into the pulp cavity, demonstrating constant penetration of hydrogen peroxide into the pulp cavity during a 1-hour bleaching session. Clinical significance A prolonged application of 40% hydrogen peroxide bleaching material for 1 hour produces constant penetration of hydrogen peroxide into the pulp cavity in vitro. How to cite this article Kwon SR, Li Y, Oyoyo U, Aprecio RM. Dynamic Model of Hydrogen Peroxide Diffusion Kinetics into the Pulp Cavity. J Contemp Dent Pract 2012;13(4):440-445.

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&lt;0.05). Color changes were significant for different tested bleaching therapies (p&lt;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&lt;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.

A novel carbamide peroxide polymeric nanoparticle bleaching gel: Color change and hydrogen peroxide penetration inside the pulp cavity

2020 ◽  
Author(s):  
Michael W. Favoreto ◽  
Mariniella P. Madureira ◽  
Viviane Hass ◽  
Bianca M. Maran ◽  
Sibelli O. Parreiras ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Color Change ◽  
Carbamide Peroxide ◽  
Pulp Cavity ◽  
Polymeric Nanoparticle

scholarly journals The Effect of Desensitizing Toothpastes and Coffee Staining on the Optical Properties of Natural Teeth and Microhybrid Resin Composites: An In-Vitro Study

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Sedanur Turgut ◽  
Hamiyet Kılınç ◽  
Kıvanç Utku Ulusoy ◽  
Bora Bagis
Keyword(s):  
Color Change ◽  
Cetylpyridinium Chloride ◽  
Human Tooth ◽  
Staining Procedure ◽  
Control Group ◽  
Human Teeth ◽  
Color Changes ◽  
Stannous Fluoride ◽  
Color Measurements ◽  
Natural Teeth

Objective. To evaluate the effect of different desensitizing toothpastes and coffee staining on the discoloration rate of natural human tooth and composite materials. Materials and Methods. A total of 56 human teeth and 56 composite specimens were used. After initial color measurements were taken, specimens and teeth were exposed to simulated toothbrushing with six desensitizing toothpastes containing different active ingredients: stannous fluoride, strontium acetate, potassium citrate and hydroxyapatite, cetylpyridinium chloride, arginine, and novamin. Specimens were then exposed to coffee staining. Throughout the staining procedure, the storing solution was refreshed every day and the specimens were brushed with the tested toothpastes. Color measurements and changes were recorded at each stage and analyzed with one-way ANOVA, Dunnett tests, and paired sample t-test (p<0.05). Results. The largest color change was obtained with the stannous fluoride toothpaste after coffee staining for natural teeth (2.6 ΔE00⁎) and composite specimens (3.1 ΔE00⁎). Coffee staining resulted in significant changes for ΔE00⁎ values of all groups, except for natural teeth brushed with a novamin-based (p= 0.06) toothpaste. For composite specimens, only the stannous fluoride and cetylpyridinium chloride-based toothpastes resulted in significant color changes relative to the control group. ΔL⁎ and Δb⁎ values were also increased after staining for all groups (p<0.05). Conclusions. Desensitizing toothpastes alone did not cause perceptible color changes; however, in combination with coffee staining, it tended to increased discoloration for both composites and natural teeth.

scholarly journals Indirect cytotoxicity of a 35% hydrogen peroxide bleaching gel on cultured odontoblast-like cells

2009 ◽  
Vol 20 (4) ◽  
pp. 267-274 ◽  
Author(s):  
Cármen Regina Coldebella ◽  
Ana Paula Dias Ribeiro ◽  
Nancy Tomoko Sacono ◽  
Flávia Zardo Trindade ◽  
Josimeri Hebling ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Cell Morphology ◽  
Total Protein ◽  
Cell Metabolism ◽  
Control Group ◽  
Bleaching Agent ◽  
Morphological Alterations ◽  
Peroxide Bleaching ◽  
Cytopathic Effects ◽  
Halogen Light

The aim of this study was to evaluate the trans-enamel and trans-dentinal effects of a 35% hydrogen peroxide (H2O2) bleaching gel on odontoblast-like cells. Enamel/dentin discs obtained from bovine incisors were mounted in artificial pulp chambers (APCs). Three groups were formed: G1- 35% H2O2; G2- 35% H2O2 + halogen light application; G3- control. The treatments were repeated 5 times and the APCs were incubated for 12 h. Then, the extract was collected and applied for 24 h on the cells. Cell metabolism, total protein dosage and cell morphology were evaluated. Cell metabolism decreased by 62.09% and 61.83% in G1 and G2, respectively. The depression of cell metabolism was statistically significant when G1 and G2 were compared to G3. Total protein dosage decreased by 93.13% and 91.80% in G1 and G2, respectively. The cells in G1 and G2 exhibited significant morphological alterations after contact with the extracts. Regardless of halogen light application, the extracts caused significantly more intense cytopathic effects compared to the control group. After 5 consecutive applications of a 35% H2O2 bleaching agent, either catalyzed or not by halogen light, products of gel degradation were capable to diffuse through enamel and dentin causing toxic effects to the cells.

scholarly journals Enamel Surface Changes After Exposure to Bleaching Gels Containing Carbamide Peroxide or Hydrogen Peroxide

2016 ◽  
Vol 41 (1) ◽  
pp. E39-E47 ◽  
Author(s):  
B Cvikl ◽  
A Lussi ◽  
A Moritz ◽  
S Flury
Keyword(s):  
Hydrogen Peroxide ◽  
Surface Roughness ◽  
Elastic Modulus ◽  
Color Change ◽  
Surface Hardness ◽  
Enamel Surface ◽  
Carbamide Peroxide ◽  
Peroxide Bleaching ◽  
Bleaching Gels ◽  
Bleaching Treatment

SUMMARY Objective This study evaluated the differences in enamel color change, surface hardness, elastic modulus, and surface roughness between treatments with four bleaching gels containing carbamide peroxide (two at 10% and one each at 35%, and 45%) and two bleaching gels containing hydrogen peroxide (two at 40%). Methods Enamel specimens were bleached and color changes were measured. Color change was calculated using either ΔE or the Bleaching Index (BI). Then, surface hardness, elastic modulus, and surface roughness of the enamel specimens were evaluated. All measurements were performed at baseline and directly after the first bleaching treatment for all carbamide peroxide– and hydrogen peroxide–containing bleaching gels. In addition, final measurements were made 24 hours after each of a total of 10 bleaching treatments for carbamide peroxide bleaching gels, and 1 week after each of a total of three bleaching treatments for hydrogen peroxide bleaching gels. Results After the last bleaching treatment, respective ΔE scores were 17.6 and 8.2 for the two 10% carbamide peroxide gels, 12.9 and 5.6 for the 45% and 35% carbamide peroxide gels, and 9.6 and 13.9 for the two 40% hydrogen peroxide gels. The respective BI scores were −2.0 and −2.0 for the two 10% carbamide peroxide gels, −3.5 and −1.5 for the 45% and 35% carbamide peroxide gels, and −2.0 and −3.0 for the two 40% hydrogen peroxide gels. Each bleaching gel treatment resulted in significant whitening; however, no significant difference was found among the gels after the last bleaching. Whitening occurred within the first bleaching treatments and did not increase significantly during the remaining treatments. Surface hardness significantly decreased after the last bleaching treatment, when 10% carbamide peroxide was used. Furthermore, significant changes in the elastic modulus or surface roughness occurred only after treatment with 10% carbamide peroxide. Conclusion All six bleaching gels effectively bleached the enamel specimens independent of their concentration of peroxide. Gels with low peroxide concentration and longer contact time negatively affected the enamel surface.

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&lt;0.001). Tukey's multiple comparisons revealed that the order of color changes was HP8, HP7&gt;HP5, HP3&gt;HCl&gt;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.

scholarly journals Influence of Restoration Type on the Cytotoxicity of a 35% Hydrogen Peroxide Bleaching Gel

2016 ◽  
Vol 41 (3) ◽  
pp. 293-304 ◽  
Author(s):  
DG Soares ◽  
N Marcomini ◽  
FG Basso ◽  
TN Pansani ◽  
J Hebling ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Cell Viability ◽  
Resin Composite ◽  
Glass Ionomer Cement ◽  
Hydrolytic Degradation ◽  
Control Group ◽  
Pulp Chamber ◽  
Peroxide Bleaching ◽  
Alp Activity

SUMMARY Objectives: The tooth/restoration interface may act as a pathway for hydrogen peroxide (H2O2) diffusion into the pulp chamber. Therefore, the influence of resin-modified glass ionomer cement (RMGIC) and resin composite simulated restorations on the cytotoxicity of an in-office bleaching gel was assessed in vitro. Materials and Methods: Cavities in enamel/dentin discs restored with RMGIC Vitremer (3M ESPE) or Single Bond/Filtek Z350 (3M ESPE) resin composite (RC) were subjected or not subjected to hydrolytic degradation (HD). A 35%-H2O2 bleaching gel was applied to simulated restored and nonrestored enamel surfaces, and culture medium in contact with the dentin substrate (extract) was collected and applied to MDPC-23 cells. Nonrestored discs subjected or not subjected to bleaching were used as positive and negative controls, respectively. Cell viability, oxidative stress, interleukin (IL)-1β expression, alkaline phosphatase (ALP) activity, and mineralized nodule deposition were evaluated. The H2O2 in the extracts was quantified. Data were subjected to statistical analysis. Results: Higher oxidative stress associated with reduced cell viability, ALP activity, and mineralized nodule deposition was observed for all bleached groups compared with the negative control group. The RMGIC/HD group, which presented the highest H2O2 diffusion, had the lowest values of cell viability, ALP activity, and mineralized nodule deposition, as well as significantly increased IL-1β expression. Conclusions: Dental cavities restored with the RMGIC subjected to hydrolytic degradation allowed for more intense diffusion of H2O2 into the pulp chamber, intensifying the toxicity of a 35%-H2O2 bleaching gel to pulp cells.

scholarly journals Influence of Simulated Pulpal Pressure on Efficacy of Bleaching Gels

2014 ◽  
Vol 15 (4) ◽  
pp. 407-412 ◽  
Author(s):  
Carlos Rocha Gomes Torres ◽  
Graziela Ribeiro Batista ◽  
Alessandra Bühler Borges ◽  
Paula Tamião Arantes ◽  
Annette Wiegand ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Artificial Saliva ◽  
Negative Control ◽  
Color Variation ◽  
Color Measurement ◽  
Control Group ◽  
Significant Difference ◽  
Bleaching Gels ◽  
Bleaching Treatment

ABSTRACT Aim The aim of this study was to investigate the influence of simulated pulpal pressure on efficacy of bleaching gels. Materials and methods Cylindrical enamel-dentin specimens from bovine teeth (3 mm diameter, enamel and dentin layer each 1 mm thick) were divided into 4 groups, according to the bleaching treatment: negative control (non-bleached), bleached with 10% carbamide peroxide (CP), bleached with 7.5% hydrogen peroxide (HP) and bleached with 35% hydrogen peroxide. Ten percent CP gel was applied for 8 h/day and 7.5% HP for 1 h/day, during 14 days. For 35% HP treatment, two sessions of 45 minutes each were employed. In intermediate periods specimens were stored in artificial saliva. Experimental groups (n = 19) were subdivided according to the simulation of pulpal pressure (25 mm Hg) during bleaching treatment. Initial color measurement and after bleaching treatment were assessed by spectrophotometry, using CIE L*a*b* system. The data were statistically analyzed by ANOVA and Dunnett's posthoc tests (p < 0.05). Results There was significant difference of ∆E for all experimental groups compared to negative control group, according to Dunnett's test (p < 0.0001). There were no significant difference for total color variation (∆E) among experimental groups (p > 0.05). Conclusion It was concluded that all bleaching gels showed bleaching efficacy compared to non-bleached group and that the simulated pulpal pressure did not influence the bleaching outcomes of the tested gels. Clinical significance Although numerous in vitro studies investigating the efficacy of bleaching agents have been performed, they do not properly simulate the pulpal pressure. In order to make these studies closer to clinical conditions, it is important to reproduce these conditions in laboratory, so the results can be more reliable. This in vitro study was performed under simulated pulpal pressure, aiming to investigate its influence on dental bleaching outcomes. How to cite this article Borges AB, Batista GR, Arantes PT, Wiegand A, Attin T, Torres CRG. Influence of Simulated Pulpal Pressure on Efficacy of Bleaching Gels. J Contemp Dent Pract 2014;15(4):407-412.

scholarly journals Effect of the Purple Corn Beverage “Chicha Morada” in Composite Resin during Dental Bleaching

Scientifica ◽  
2016 ◽  
Vol 2016 ◽  
pp. 1-6
Author(s):  
Eric Dario Acuña ◽  
Leyla Delgado-Cotrina ◽  
Francisco Aurelio Rumiche ◽  
Lidia Yileng Tay
Keyword(s):  
Hydrogen Peroxide ◽  
Green Tea ◽  
Composite Resin ◽  
Color Change ◽  
Color Measurement ◽  
Distilled Water ◽  
Dental Bleaching ◽  
Color Changes ◽  
Bleaching Procedure ◽  
Purple Corn

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

scholarly journals A Comparison of the Bleaching Effectiveness of Chlorine Dioxide and Hydrogen Peroxide on Dental Composite

2014 ◽  
Vol 25 (6) ◽  
pp. 524-527 ◽  
Author(s):  
Anirudha Agnihotry ◽  
Karanjot S. Gill ◽  
Deepak Singhal ◽  
Zbys Fedorowicz ◽  
Sambit Dash ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Chlorine Dioxide ◽  
Color Change ◽  
Dental Composite ◽  
Control Group ◽  
Distilled Water ◽  
Water Control ◽  
Color Differences ◽  
Clinically Significant ◽  
Office Systems

This study was carried out to verify if composites could be bleached using chlorine dioxide as compared with hydrogen peroxide. 3M ESPE Filtek Z350 Universal Restorative discs were prepared (n=40), with dimensions 5 mm diameter x 2 mm thickness. The discs were divided into 4 groups of 10 discs each. Color assessment was performed by CIEDE2000. The discs were stained with coffee, tea, wine and distilled water (control) solutions for 14 days, 5 hours daily. Color assessment was repeated on stained discs and followed by bleaching of 5 discs from each group using chlorine dioxide and hydrogen peroxide in-office systems. Finally, a last color assessment was performed and compared statistically. DE2000 after bleaching was very close to baseline for both the bleaching agents, although chlorine dioxide showed better results than hydrogen peroxide. After staining, there was a clinically significant discoloration (∆E2000≥3.43) for the tea, coffee and wine groups, and discoloration (∆E2000) was seen more in the wine group as compared to tea and coffee. Overall, the control group (distilled water) had the least color change in the three intervals. After bleaching, the color in all specimens returned close to the baseline. The color differences between bleaching and baseline were less than 3.43 for all groups. The obtained results show that chlorine dioxide is slightly superior to hydrogen peroxide in the bleaching of composites, while maintaining the shade of the composite close to the baseline.

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