Effects of pH and Application Technique of In-office Bleaching Gels on Hydrogen Peroxide Penetration into the Pulp Chamber

2019 ◽  
Vol 44 (6) ◽  
pp. 659-667 ◽  
Author(s):  
L Balladares ◽  
LF Alegría-Acevedo ◽  
A Montenegro-Arana ◽  
LA Arana-Gordillo ◽  
C Pulido ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Color Change ◽  
Acidic Ph ◽  
Alkaline Ph ◽  
Pulp Chamber ◽  
Pulp Tissue ◽  
Application Technique ◽  
Significant Difference ◽  
Bleaching Gels

SUMMARY Objective: This in vitro study aimed to quantify the penetration of hydrogen peroxide (HP) into the pulp chamber in teeth submitted to in-office bleaching with varied pH and application techniques. The color change and pH of the in-office bleaching product during application was also evaluated. Methods and Materials: Ninety-six human premolars were used and randomly divided into 10 groups (n=9) according to the following combination of factors: pH of in-office bleaching agents (two neutral/alkaline pH: Opalescence Boost 38% and Whiteness HP Blue 35% and three acidic pH: Whiteness HP Maxx 35%, Lase Peroxide Sensy 35%, and Total Blanc Office 35%) and application modes (for 3 × 15 minutes [3×15] and 1 × 45 minutes [1×45]). An additional group of non-bleached teeth (control; n=6) was added. First, all teeth were sectioned 3 mm from the cementoenamel junction and the pulp tissue was removed. An acetate buffer was placed in the pulp chamber of all teeth. After bleaching, this solution was transferred to a glass tube in which HP was allowed to react with other components, resulting in a pink solution. The optical density of this pink solution was measured using ultraviolet-visible spectroscopy and converted into amount of HP. Color change before and 1 week after bleaching was evaluated using a digital spectrophotometer. A pH meter with a 6-mm circular and flat surface was used in contact with the enamel surface to quantify the pH of the bleaching gels during application. Data were analyzed using two-way analysis of variance and Tukey tests (α=0.05). Results: Overall, lower mean HP penetration values were observed for Opalescence Boost 38% and Whiteness HP Blue 35% compared with other bleaching gels (p<0.05). Opalescence Boost 38% and Whiteness HP Blue 35% were not influenced by the application technique (p>0.05). However, lower mean HP penetration values were observed for Whiteness HP Maxx 35%, Total Blanc Office 35%, and Lase Peroxide Sensy 35% when using the 3×15 application technique compared with the 1×45 technique (p<0.05). Significant whitening was detected and no significant difference of color change was observed between groups (p>0.54). The pH did not change during the 3×15 application technique; however, all acidic bleaching gels significantly decreased in pH when applied for 1×45 (p<0.01). Conclusions: The amount of HP that reaches the pulp chamber was lower when neutral/alkaline pH gels were used, independently of the application technique. When considering acidic pH gels, it is preferable to use the 3×15 application technique, mainly because longer application time (1×45) results in lower pH. No difference was observed between groups with regards to color change.

scholarly journals Impact of Bleaching before or after Veneer Preparation on Color Masking Ability of Laminate Veneers: An In Vitro Study

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Gollshang Ahmad Mhammed Dalloo ◽  
Bestoon Mohammed Faraj ◽  
Abdulsalam Rasheed Al-Zahawi
Keyword(s):  
Hydrogen Peroxide ◽  
Color Change ◽  
In Vitro Study ◽  
Tooth Discoloration ◽  
Significant Difference ◽  
Color System ◽  
The Difference ◽  
Laminate Veneers ◽  
Cielab Color

Purpose. This study evaluates the effect of bleaching before or after veneer preparation and the depth of preparation on color masking ability of laminate veneers. Methods. Sixty extracted premolars were artificially stained to vita shade A4, verified by digital spectrophotometer (Vita Easy Shade V), and then divided into three groups: NB = nonbleached , BBP = bleaching before preparation, and BAP = bleaching after preparation. Based on the preparation depths, each group was further divided into two subgroups: S 1 = 0.5   mm and S 2 = 1.0   mm . BBP and BAP were subjected to one session of in-office bleaching using 35% hydrogen peroxide. IPS e-max CAD veneers of 0.5 and 1.0 mm thickness (corresponding to the preparation depths) of the same shade and translucency (HT A1) were cemented immediately to the bleached surfaces. Immediately after cementation, the color change Δ E between the baseline (after staining) and the resulted shades was measured using the Vita Easy Shade V digital spectrophotometer and CIELab color system. Results. Bleached groups exhibited a significant Δ E value compared to the nonbleached group ( p < 0.05 ). BAP showed the highest Δ E value. No significant difference was found between BBP and BAP. S2 revealed a significant Δ E value than S1 ( p < 0.05 ). No significant difference was found between S1of BAP and S2 of NB, BBP, and BAP ( p > 0.05 ). Regarding the color coordinates, the difference between the tested groups was highly significant in lightness ( Δ L ∗ ) ( p < 0.001 ), while no significant differences were found in green/red value ( Δ a ∗ ) and yellow/blue value ( Δ b ∗ ) ( p > 0.05 ). Conclusions. In cases of severe tooth discoloration, one session of in-office bleaching before or after veneer preparation and the preparation depth do not influence the color masking ability of laminate veneers.

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.

Effect of Bleaching Gel Viscosity on Tooth Whitening Efficacy and Pulp Chamber Penetration: An In Vitro Study

2018 ◽  
Vol 43 (3) ◽  
pp. 326-334 ◽  
Author(s):  
SR Kwon ◽  
FNU Pallavi ◽  
Y Shi ◽  
U Oyoyo ◽  
A Mohraz ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Rheological Properties ◽  
Color Change ◽  
Negative Control ◽  
Tooth Color ◽  
Tooth Structure ◽  
Significant Difference ◽  
Bonferroni Test ◽  
Medium Viscosity

SUMMARY Objectives: Whitening efficacy has been related to hydrogen peroxide (HP) diffusion into tooth structure. However, little information is available relating rheological properties to whitening efficacy. The purpose was to evaluate the whitening efficacy and HP penetration level of a 10% HP gel at three different viscosities and to compare them to a strip delivery system. Methods and Materials: Extracted molars (n=120) were randomly assigned into five groups (n=24/ group): NC_MED (negative control; median): medium viscosity gel without HP; LOW: 10% HP gel (low viscosity experimental gel, Ultradent Products Inc); MED: 10% HP gel (medium viscosity experimental gel, Ultradent); HIGH: 10% HP gel (high viscosity gel, Ultradent); and CWS: Crest 3D Whitestrips 1-Hour Express (Procter & Gamble). All teeth were subjected to five 60-minute whitening sessions. Instrumental color measurements were performed at baseline (T0), and 1-day after each application (T1-T5), and 1-month after whitening (T6). HP penetration was estimated with leucocrystal violet and horseradish peroxidase. A Kruskal-Wallis test and post hoc Bonferroni test were performed to assess the difference in tooth color change and HP penetration among the groups (α=0.05). Results: Hydrogen peroxide penetration levels and overall color changes at T6 were 0.24 μg/mL / 2.80; 0.48 μg/mL / 8.48; 0.44 μg/mL / 7.72; 0.35 μg/mL / 8.49; 0.36 μg/mL / 7.30 for groups NC, LOW, MED, HIGH, and CWS, respectively. There was a significant difference for HP penetration, while there was no significant difference among the four experimental groups for tooth color change. Conclusion: Rheological properties should be considered when developing new whitening formulations.

Effects of the Concentration and Composition of In-office Bleaching Gels on Hydrogen Peroxide Penetration into the Pulp Chamber

2015 ◽  
Vol 40 (2) ◽  
pp. E76-E82 ◽  
Author(s):  
AP Mena-Serrano ◽  
SO Parreiras ◽  
EMS do Nascimento ◽  
CPF Borges ◽  
SB Berger ◽  
...  
Keyword(s):  
Hydrogen Peroxide ◽  
Acetate Buffer ◽  
Acetate Buffer Solution ◽  
Control Group ◽  
Pulp Chamber ◽  
Pulp Tissue ◽  
Buffer Solution ◽  
Bleaching Procedure ◽  
Blue Solution

SUMMARY In tooth whitening, the hydrogen peroxide (HP) diffuses in the enamel and dentin, reaching the pulp. This in vitro study aimed to quantify the penetration of HP in the pulp chamber in teeth submitted to bleaching agents of different concentrations of HP without calcium (HP 20% [20CF], HP 35% [35CF]) and with calcium (HP 20% [20CC], HP 35% [35CC]). Method Fifty human premolars were sectioned 3 mm from the cemento-enamel junction and the pulp tissue was removed. The teeth were divided into five groups according to treatment and with a control group (n=10). An acetate buffer solution was placed in the pulp chamber of all teeth. The control group was exposed only to distilled water, while the other groups were treated with a bleaching procedure, according to the manufacturer's recommendations. After treatment, the acetate buffer solution was transferred to a glass tube in which leuco-crystal violet and peroxidase solutions were added, resulting in a blue solution. The optical density of this blue solution was determined spectrophotometrically and converted into micrograms equivalent to the HP. Data were analyzed using analysis of variance and Tukey tests (α=0.05). Results The HP concentration did not affect the HP inside the pulp chamber, but the presence of calcium significantly reduced it (p&lt;0.0001). Conclusion The amount of HP that reaches the pulp chamber depends on the bleaching protocol and the product employed, and it seems to be less affected by HP concentration.

Effects of an In-office Bleaching System (ZOOM™) on Pulp Chamber Temperature In Vitro

2007 ◽  
Vol 8 (4) ◽  
pp. 19-26 ◽  
Author(s):  
A. Rüya Yazici ◽  
Gerard Kugel ◽  
Azita Khanbodaghi
Keyword(s):  
Temperature Rise ◽  
Temperature Increase ◽  
Pulp Chamber ◽  
Pulp Tissue ◽  
Maxillary Central Incisor ◽  
Group I ◽  
Significant Difference ◽  
Chamber Temperature ◽  
Group Ii

Abstract Aim Several new techniques and materials for in-office bleaching have been introduced recently. The aim of this in vitro study was to measure the temperature increase in the pulp chamber of extracted teeth produced by the Zoom!™ in-office bleaching system and to investigate the influence of this light in conjunction with the bleaching gel on pulp temperature rise. Methods and Materials Ten extracted, caries-free, unrestored human maxillary central incisor teeth were used for the study. The root of each tooth was cut approximately 2-3 mm apical to the cementoenamel junction (CEJ), and the apical orifice of the root canal was enlarged. The remaining pulp tissue was removed and the empty pulp chamber was filled with a heat sink compound. A thin K-type thermocouple was inserted into the pulp chamber through the cut root area. The root surfaces of the teeth were partially submerged in a water bath during the testing procedure at 37°C. A whitening gel containing 25% hydrogen peroxide was applied to the buccal surfaces of all ten teeth and exposed to a Zoom!™ activation light for twenty minutes for three times; this was designated as Group I. The same teeth were then exposed with the Zoom!™ light for the same time period without the application of the bleaching gel and designated as Group II. The intrapulpal temperature pre-treatment (baseline) and the temperature increase during treatment was measured for both treatment groups. Results There was a statistically significant difference between the two groups (p=0.003). Application of the Zoom!™ light in conjuction with the application of bleaching gel produced a greater temperature rise than did the light alone. The mean temperature rise for Group I (light and bleaching gel) was 1.11°C (0.18°C) and 1.01°C (0.12°C) for Group II (light alone) at the end of a five-minute exposure. Conclusion The Zoom!™ light either used with or without bleaching gel showed no significant increase in the intrapulpal temperature of teeth when used for the recommended exposure time. Citation Yazici AR, Khanbodaghi A, Kugel G. Effects of an In-office Bleaching System (ZOOM™) on Pulp Chamber Temperature In Vitro. J Contemp Dent Pract 2007 May;(8)4:019-026.

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.

Effect of 10% and 15% Carbamide Peroxide on Fracture Toughness of Human Dentin In Situ

2013 ◽  
Vol 38 (2) ◽  
pp. 142-150 ◽  
Author(s):  
LE Tam ◽  
P Bahrami ◽  
O Oguienko ◽  
H Limeback
Keyword(s):  
Fracture Toughness ◽  
Placebo Group ◽  
Color Change ◽  
Carbamide Peroxide ◽  
Tooth Sensitivity ◽  
Custom Made ◽  
Dental Hard Tissues ◽  
Significant Difference

SUMMARY Purpose Although damage to the structural integrity of the tooth is not usually considered a significant problem associated with tooth bleaching, there have been some reported negative effects of bleaching on dental hard tissues in vitro. More studies are needed to determine whether the observed in vitro effects have practical clinical implications regarding tooth structural durability. Objectives This in situ study evaluated the effect of 10% and 15% carbamide peroxide (CP) dental bleach, applied using conventional whitening trays by participants at home, on the fracture toughness of dentin. Methods Ninety-one adult volunteers were recruited (n ≈ 30/group). Compact fracture toughness specimens (approximately 4.5 × 4.6 × 1.7 mm) were prepared from the coronal dentin of recently extracted human molars and gamma-radiated. One specimen was fitted into a prepared slot, adjacent to a maxillary premolar, within a custom-made bleaching tray that was made for each adult participant. The participants were instructed to wear the tray containing the dentin specimen with placebo, 10% CP, or 15% CP treatment gel overnight for 14 nights and to store it in artificial saliva when not in use. Pre-bleach and post-bleach tooth color and tooth sensitivity were also evaluated using ranked shade tab values and visual analogue scales (VASs), respectively. Within 24–48 hours after the last bleach session, the dentin specimens were tested for fracture toughness using tensile loading at 10 mm/min. Analysis of variance, Kruskal-Wallis, χ2, Tukey's, and Mann-Whitney U tests were used for statistical analysis. The level of significance was set at p&lt;0.05 for all tests, except for the Mann-Whitney U tests, which used a Bonferroni correction for post hoc analyses of the nonparametric data (p&lt;0.017). Results The placebo, 10% CP, and 15% CP groups contained 30, 31, and 30 participants, respectively. Mean fracture toughness (+ standard deviation) for the placebo, 10% CP, and 15% CP groups were 2.3 ± 0.9, 2.2 ± 0.7, and 2.0 ± 0.5 MPa*m1/2 respectively. There were no significant differences in mean fracture toughness results among the groups (p=0.241). The tooth sensitivity VAS scores indicated a significantly greater incidence (p=0.000) and degree of tooth sensitivity (p=0.049 for VAS change and p=0.003 for max VAS) in the bleach groups than in the placebo group. The color change results showed generally greater color change in the bleach groups than in the placebo group (p=0.008 for shade guide determination and p=0.000 for colorimeter determination). Conclusions There were no significant differences in in situ dentin fracture toughness results among the groups. The results of this study provide some reassurance that dentin is not overtly weakened by the bleaching protocol used in this study. However, the lack of a statistically significant difference cannot be used to state that there is no effect of bleach on dentin fracture toughness.

Six-month Follow-up of the Effect of Nonvital Bleaching on IL-1β and RANK-L: A Randomized Clinical Trial

2019 ◽  
Vol 44 (6) ◽  
pp. 581-588 ◽  
Author(s):  
C Bersezio ◽  
J Estay ◽  
M Sáez ◽  
F Sánchez ◽  
R Vernal ◽  
...  
Keyword(s):  
Clinical Trial ◽  
Hydrogen Peroxide ◽  
Randomized Clinical Trial ◽  
Gingival Crevicular Fluid ◽  
Color Change ◽  
Double Blind ◽  
Time Points ◽  
Periodontal Tissues ◽  
Significant Difference ◽  
Spearman Test

SUMMARY Objectives: It has been reported that bleaching generates an increase in the activity of osteoclasts in vitro. We quantified the RANK-L and IL-1β biomarkers in a double-blind, randomized clinical trial evaluating the in vivo effect of hydrogen peroxide (35%) and peroxide carbamide (37%) six months after whitening. Methods and Materials: Fifty volunteers participated, each with color change in a nonvital tooth. Fifty teeth were randomly divided into two groups (n=25), and the teeth were bleached using either 35% hydrogen peroxide (G1) or 37% carbamide peroxide (G2). Intracoronal bleaching was carried out by a technical “walking bleach” over four sessions. Gingival crevicular fluid samples were collected and used to quantify the IL-1β and RANK-L secreted levels. Samples of six periodontal sites (three vestibular and three palatal) were collected for up to six months (at the beginning of the study [baseline] and at one week, one month, and six months posttreatment). The color change was visually monitored using the Vita Bleached Guide (ΔSGU). Results: Comparing each time to baseline assessment, a significant increase in the levels of IL-1β and RANK-L across time points was detected (p&lt;0.05). The color change was 4 in G1 and G2, and a statistically significant difference (p&lt;0.05) was found at the month time point between the groups. Using the Spearman test, a strong correlation (&gt;0.8) between the IL-1β and RANK-L levels in both groups at all time points was detected. Conclusions: Nonvital bleaching using a technical walking bleach induces an increase in the IL-1β and RANKL production in periodontal tissues, which persists for six months after treatment. Both biomarkers were highly correlated in both groups and at all time points.

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.

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