Bleaching and microstructural effects of low concentration hydrogen peroxide photoactivated with LED/laser system on bovine enamel

Author(s):  
Joatan Lucas de Sousa Gomes Costa ◽  
João Felipe Besegato ◽  
Milton Carlos Kuga
2020 ◽  
Vol 02 ◽  
Author(s):  
RM Garcia ◽  
WF Vieira-Junior ◽  
JD Theobaldo ◽  
NIP Pini ◽  
GM Ambrosano ◽  
...  

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.


2012 ◽  
Vol 37 (5) ◽  
pp. 518-525 ◽  
Author(s):  
AM de Arruda ◽  
PH dos Santos ◽  
RH Sundfeld ◽  
SB Berger ◽  
ALF Briso

SUMMARY This study evaluated the microhardness and histomorphology of bovine enamel when 35% hydrogen peroxide is used. A total of 44 specimens were adapted to removable devices used by 11 individuals subjected to dental caries challenge. A decrease in microhardness was observed for all groups after the cariogenic challenge. Microscopic analysis revealed that fragments subjected to cariogenic challenge associated with bleaching had more intense superficial histologic changes, but the depth of the lesions remained unchanged. It was concluded that 35% hydrogen peroxide enhanced the reduction in hardness and histomorphologic changes in the enamel surface exposed to cariogenic challenge.


2014 ◽  
Vol 15 (4) ◽  
pp. 392-398 ◽  
Author(s):  
Wilcilene Costa Nascimento ◽  
Yasmin do Socorro Batista de Lima Gomes ◽  
Larissa Dias Alexandrino ◽  
Hilton Tulio Costi ◽  
José Otávio Carrera Silva ◽  
...  

ABSTRACT Aim The aim of this in vitro study was to evaluate the effects of different sodium fluoride (NaF) concentrations and pH values on the Knoop hardness (KHN), surface roughness (SR), and morphology of bovine incisors bleached with 35% hydrogen peroxide (HP). Materials and methods Sixty-five bovine incisors were fragmented (5 mm2 × 2 mm) and distributed in 5 groups: Control (unbleached), Low NaF/Acidic (35% HP + 1.3% NaF, pH 5.5), Low NaF/Neutral (35% HP + 1.3% NaF, pH 7.0), High NaF/ Acidic (35% HP + 2% NaF, pH 5.5), and High NaF/Neutral (35% HP + 2% NaF, pH 7.0). KHN analysis was performed with a microhardness tester under a load of 25 gf for 5 seconds. The average SR was obtained with a rugosimeter. KHN and SR were analyzed before and after treatments. For morphological analysis, specimens were dehydrated and gold-sputtered, and scanning electron micrographs were obtained and analyzed by 3 examiners with a double-blinded technique. KHN and SR results were analyzed by one-way ANOVA and Tukey's test (p < 0.05). Results Only the Low NaF/Acidic and Low NaF/Neutral groups showed significant differences between the initial and final KHN values. All bleached groups presented significant differences between the initial and final SR values. Among the bleached groups, the least and most morphological changes were shown by the High NaF/Neutral and the Low NaF/Acidic group, respectively. Conclusion Treatment with 35% HP and 2% NaF at pH 7.0 promoted the least changes in morphology, hardness and roughness among the bleached groups. Clinical significance In-office bleaching with high-concentration HP and 2% NaF at neutral pH promoted the least changes in enamel hardness, SR, and morphology compared to other treatments. How to cite this article Nascimento WC, Gomes YSBL, Alexandrino LD, Costi HT, Silva JOC Jr, Silva CM. Influence of Fluoride Concentration and pH Value of 35% Hydrogen Peroxide on the Hardness, Roughness and Morphology of Bovine Enamel. J Contemp Dent Pract 2014;15(4):392-398.


2004 ◽  
Vol 23 (4) ◽  
pp. 517-521 ◽  
Author(s):  
Hyun-Jin PARK ◽  
Tae-Yub KWON ◽  
Soon-Hyun NAM ◽  
Hyun-Jung KIM ◽  
Kyo-Han KIM ◽  
...  

1982 ◽  
Vol 60 (7) ◽  
pp. 848-852 ◽  
Author(s):  
Yoshiro Ogata ◽  
Kazushige Tanaka

The oxidation of diphenyl sulfide (Ph2S) by hydrogen peroxide in the presence of a catalytic amount of sodium metavanadate (NaVO3) has been studied kinetically by means of iodometry of hydrogen peroxide. The reaction rate is expressed as: v = k[NaVO3]st[Ph2S]2, when the concentration of catalyst is very low and [Ph2S]0/[H2O2]0 > 2, where []st and []0 mean stoichiometric and initial concentration, respectively. The effective oxidant may consist of polymeric as well as monomeric peroxyvanadate in view of the effect of concentration of catalyst on the rate. The main oxidizing species at low concentration of catalyst seems to be diperoxyvanadate VO5−. The rate constant k2 in v = k2[Ph2S]2 tends to decrease with initial concentration of H2O2, which is present in excess of the catalyst. A probable mechanism for the oxidation is discussed.


1989 ◽  
Vol 53 (3) ◽  
pp. 835-836 ◽  
Author(s):  
Koichi Yoshinaga ◽  
Kayo Yamamoto ◽  
Hiroe Yoshioka ◽  
Kunihiko Hasegawa

2012 ◽  
Vol 2012 ◽  
pp. 1-6 ◽  
Author(s):  
Alessandra B. Borges ◽  
Carlos R. G. Torres ◽  
Paulo A. B. de Souza ◽  
Taciana M. F. Caneppele ◽  
Luciana F. T. F. Santos ◽  
...  

Thisin vitrostudy evaluated the effect of 35% hydrogen peroxide (HP) bleaching gel modified or not by the addition of calcium and fluoride on enamel susceptibility to erosion. Bovine enamel samples (3 mm in diameter) were divided into four groups (n=15) according to the bleaching agent: control—without bleaching (C); 35% hydrogen peroxide (HP); 35% HP with the addition of 2% calcium gluconate (HP + Ca); 35% HP with the addition of 0.6% sodium fluoride (HP + F). The bleaching gels were applied on the enamel surface for 40 min, and the specimens were subjected to erosive challenge with Sprite Zero and remineralization with artificial saliva for 5 days. Enamel wear was assessed using profilometry. The data were analyzed by ANOVA/ Tukey’s test (P<0.05). There were significant differences among the groups (P=0.009). The most enamel wear was seen for C (3.37±0.80 μm), followed by HP (2.89±0.98 μm) and HP + F (2.72±0.64 μm). HP + Ca (2.31±0.92 μm) was the only group able to significantly reduce enamel erosion compared to C. The application of HP bleaching agent did not increase the enamel susceptibility to erosion. However, the addition of calcium gluconate to the HP gel resulted in reduced susceptibility of the enamel to erosion.


2020 ◽  
Author(s):  
Juan Estay ◽  
Pablo Angel ◽  
Cristian Bersezio ◽  
Mateus Tonetto R ◽  
Gilbert Jorquera ◽  
...  

Abstract Background: Dental bleaching in traditional concentrations generates greater sensitivity. In this respect, new systems of lower concentration of hydrogen peroxide for tooth bleaching appeared, with color stability unknown over time. The aim of this study was to compare the change and stability of color with low-concentration (6%) hydrogen peroxide gel in an in-office bleaching setting relative to conventional 37.5% gel, including their effects on psychosocial and esthetic self-perception, after one year.Methods: Patients (n=25) were assessed at 12 months post bleaching treatment (whitening with 6% chemo-activated alkaline formula gel versus 37.5% traditional concentration gel). Color changes were measured objectively using total variation in color (ΔE), and subjectively using Vita Classical and Vita Bleached scale (ΔSGU) by calibrated evaluators (Kappa=0.85). The Psychosocial Impact of Dental Aesthetics Questionnaire (PIDAQ) and Oral Health Impact Profile (OHIP-14) aesthetic questionnaires were used to measure the self-perception and the psychosocial impact of the bleaching protocols.Results: The effect (ΔE) of 37.5% HP (8.37 ± 2.73) was significantly better than that of 6% HP (5.27 ± 2.53) in terms of color rebound after one year of follow-up. There were significant differences in psychosocial impact and esthetic self-perception measurements prior to bleaching versus one-year post-whitening time points; positive effects were maintained.Conclusions: Low concentration (6%) achieved effective bleaching with good stability after one year, accompanied by a positive psychosocial impact and enhanced self-perception at follow-up.Trial registration: NCT03217994 (before enrollment of the first participant). Data register: July 14, 2017


2021 ◽  
Vol 10 (5) ◽  
pp. e30410514754
Author(s):  
Thaís Miranda Xavier de Almeida Justi ◽  
Karla Lorene de França Leite ◽  
Laísa Inara Gracindo Lopes ◽  
Narcy Sheilla Rodrigues ◽  
João Victor Frazão Câmara ◽  
...  

Objective: To evaluate the influence of acid erosion caused by the daily intake of lemon juice or apple cider vinegar, associated with immediate dental whitening, on bovine enamel. Materials and Methods: 30 bovine teeth were sectioned to obtain enamel blocks and were distributed into three groups (n = 10): G1- Tooth whitening with 35% hydrogen peroxide; G2- Tooth whitening with 35% hydrogen peroxide + lemon juice and G3 - Tooth whitening with 35% hydrogen peroxide + apple cider vinegar. Treatments were performed for 21 days, the varnish was removed and the analysis of loss of structure and surface roughness were performed by means of non-contact 3D Confocal Chromatic Profilometer. The roughness data obtained were analyzed by Kruskal-Wallis and Mann-Whitney non-parametric tests. Results: All groups exhibited greater roughness (Sa) on the side exposed to the treatments (G1 = 3.17b; G2 = 4.17b; G3 = 3.99b) compared to the unexposed side (G1 = 2.55a; G2 = 3.94a; G3 = 2.40a). There was a statistically significant difference among the groups evaluated, being G1 (3.17A) <G3 (3.99C) <G2 (4.17B). Conclusion: 35% hydrogen peroxide has the least erosive potential when compared to its association with vinegar and to lemon juice.


Sign in / Sign up

Export Citation Format

Share Document