An Analysis of Dental Enamel after Bleaching using 35% Hydrogen Peroxide with Energy-dispersive X-ray Spectroscopy (original) (raw)
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International Journal of Science and Research , 2024
This study compares the enamel mineral content after bleaching using In-Office, At-Home and Combined Techniques, utilizing a Scanning Electron Microscope (SEM) equipped with Energy Dispersive X-Ray Analysis (EDX). Fifty-six human premolar teeth were divided into four groups, each subjected to different bleaching techniques. Results indicated that In-Office bleaching led to the most significant loss of calcium and phosphorus, while At-Home and Combined techniques showed less mineral reduction. Statistical analysis confirmed significant differences in mineral content across the groups
Materials Letters, 2015
Nowadays, there are a number of methods very effectives for the dental bleaching, which are typically strong oxidizing agents, as the hydrogen peroxide, applied directly to the tooth surface. After bleaching, several research studies have been carried out to evaluate the efficacy of bleaching agents on teeth, there being a great controversy concerning the techniques used and their pre-treatment requirements derived, which could alter the final results. In fact, there is a strong necessity to develop different approach to determine the real consequences of bleaching treatment by using an unchangeable and entire tooth. Herein, to evaluate the effects of 38% (p/v) hydrogen peroxide treatment onto morphological, chemical and structural features in the human enamel and dentin, environmental scanning electron microscopy, electron probe micro analyzer and X-ray diffraction techniques have been used. Although such effects have been widely investigated with several techniques, including XRD and SEM, the novelty of this study lies on the techniques and methodology used to characterize the human teeth after bleaching treatment. This approach allows carrying out the analyses without any previous pretreatment, such as powdering, dried or metal sputtering, and its study in the same tooth piece before and after bleaching, which avoids the possible intrinsic differences derived from the use of different pieces. The obtained results display that neither the structural nor the chemical features of both enamel and dentin are altered after bleaching treatment. However, the morphology of the enamel is notably altered, appearing pronounced pores which could affect to the possible bacterial colonization. These findings put an end to the controversies on the different obtained results in the literature of the bleaching effects in the enamel and set standards for future studies.
Mechanisms for Low-Light Therapy IX, 2014
Dental bleaching is a frequently requested procedure in clinical dental practice. The literature is contradictory regarding the effects of bleaching agents on both morphology and demineralization of enamel after bleaching. The aim of this study was to analyze by SEM the effect of 35% neutral hydrogen peroxide cured by green LED. Buccal surfaces of 15 pre-molars were sectioned and marked with a central groove to allow experimental and control groups on the same specimen. For SEM, 75 electron micrographs were evaluated by tree observers at 43X, 220X and 1000X. Quantitative analysis for the determination of the surface elemental composition of the samples through X-ray microanalysis by SEM was also performed. The protocol tested neither showed significant changes in mineral composition of the samples nor to dental enamel structure when compared to controls. SEM analysis allowed inferring that there were marked morphological differences between the enamel samples highlighting the need for the use of the same tooth in comparative morphological studies. The tested protocol did not cause morphological damage the enamel surface when compared to their respective controls.
International Journal of Dentistry
Purpose. The purpose of this study was to evaluate changes in calcium and phosphorus content in dental enamel when subjected to “in-office” whitening for an extended time by using a 35% hydrogen peroxide solution, with and without calcium. Materials and Methods. 10 human teeth, from which the roots had been removed, were embedded in epoxy resin, and their surfaces were smoothed. The specimens were divided into two groups; in group 1, a whitening solution without calcium was used, while in group 2, the solution included calcium. Each specimen was evaluated at 6 different points before the bleaching treatment, and these points were reassessed after each session. A total of five sessions were carried out. Concentrations of calcium and phosphorus were measured by using the technique of X-ray fluorescence. Results. After performing a statistical analysis, it was found that there was no statistically significant loss of calcium and phosphorus during the whitening treatment, and the groups...
The Open Dentistry Journal
Background: The tooth bleaching treatment can cause structural changes in the surfaces of the teeth; these changes can increase the absorption of staining agents. Purpose: This study assessed surface morphological changes and predisposition to staining in dental enamel bleached with different hydrogen peroxide (HP) concentrations, with or without the use of a light source (LS). Methods: 25 bovine incisor specimens were divided into five groups (n = 5): Control- no treatment; HP35 - hydrogen peroxide 35%; HP35+LED - hydrogen peroxide 35% + light emission; HP20 - hydrogen peroxide 20%; and HP7 - hydrogen peroxide 7,5%. Twenty days after bleaching, the specimens were immersed in staining solutions four hours a day for 28 days. The morphological alterations of the bovine enamel surface were evaluated by means of scanning electron microscopy, X-ray dispersive energy spectroscopy and predisposition to the staining of the brightened enamel by means of colorimetry. Results: ANOVA with Tukey...
Photomedicine and Laser Surgery, 2010
Objective: The objective of this study was to evaluate the effects of the combined use of light irradiation (LIR, halogen light, or LED=diode laser) and 35% hydrogen peroxide (35%HP) on human enamel mineral content. Background Data: The use of high-intensity light has been indicated for acceleration of the rate of chemical bleaching; however, it is not known whether LIR can promote additional effects on enamel surfaces during the bleaching. Materials and Methods: One hundred enamel samples were obtained from third molars and randomly divided into 10 groups (n ¼ 10). The control group (CG) remained untreated. Three whitening products were used: Whiteness HP Maxx, Pola Office, and Opalescence Xtra. Bleaching consisted of one session, and the products were applied three times to each specimen for 10 min each. The products were subjected, or not, to LIR during treatment with halogen light or LED=diode laser. The mineral concentration of enamel was determined before and after treatments using an FT-Raman spectroscope (FT-RS), and the amount of calcium lost from the bleached enamel surfaces was quantified with an atomic absorption spectrometer (AAS). Results: FT-RS results showed a decreased mineral content after all treatments, with the exception of Pola Office when irradiated with LED=diode laser and the CG. The losses of calcium detected for Pola Office and Opalescence Xtra were similar for the three situations (without or with light irradiations), whereas for Whiteness HP Maxx the lowest calcium loss was detected without LIR. Conclusion: Most of the bleaching treatments investigated, in combination with LIR or not, can reduce the mineral content of enamel surface. LIR increased the calcium loss for Whiteness HP Maxx; no effects were observed for Pola Office and Opalescence Xtra.
International Journal of Advanced Research (IJAR), 2018
Bleaching agents have effect on chemical and morphological structure of enamel that must be taken into account when this therapy is used. Aim: reveal and compare the effect of two bleaching agents containing a high a concentration of hydrogen peroxide (HP) and carbamide peroxide (CP) on enamel surface and evaluate the re-mineralizing effect of amorphous calcium phosphate gel (ACP) on enamel surface. Material and method: 32 extracted human upper first premolars were divided into 4 Control groups (CG) (before bleaching procedure), was named as: CG I, CG II, CG III and CG IV. 4 Experimental groups (EG) in which the teeth of the control groups utilized as experimental after bleaching procedure. Teeth were subjected to 40% HP in EGI, 35% CP bleaching in EGII, 40% HP & ACP in EGIII and 35 % CP & ACP in EGIV. All groups were prepared to SEM analysis and EDAX. Results: Both HP and CP significantly altered enamel superficial surface structure causing irregular surface, erosive lesions and craters. Globular precipitates covering the entire enamel surface and occlusion of enamel rod ends were detected following ACP application.The chemical profile results revealed decrease in Ca and P contents of enamel surface following bleaching, while they increased after application of ACP and the opposite was to the carbon content. Conclusion: Hydrogen peroxide and carbamide peroxide have an erosive effect on enamel surface while ACP has a re-mineralizing effect.
Hydrogen peroxide whitens teeth by oxidizing the organic structure
j o u r n a l o f d e n t i s t r y 4 0 s (2 0 1 2) e 2 5 – e 3 3 a b s t r a c t Objectives: The mechanism of tooth bleaching using peroxide oxidizers is not fully understood. It is unknown whether peroxide radicals make teeth whiter by deproteinizing, demineralizing, or oxidizing tooth tissues. This study was designed to define the mechanism of tooth bleaching and determine which of tooth enamel chemical components is/are affected by bleaching. Methods: Sixty sound teeth were collected from adult patients. The teeth were divided into 6 equal groups (n = 10). Groups 1, 2, 3 and 4 were treated for 4 days with one of the following solutions: deproteinizing (NaOH) that removes organic content, demineralizing (EDTA) that decalcifies the mineral content, oxidizing (H 2 O 2) and distilled water (control). Group 5 and 6 were pre-treated with either deproteinizing or demineralizing solutions before treating them with oxidizing solutions for 4 days. Changes in enamel elemental ratios, crystallinity index and tooth shade parameters of the treated teeth were examined by means of EDS, Raman spectroscopy and shade-spectrophotometry. The data obtained was analysed with Wilcoxon Signed-Ranks Test, and the statistical signicance was set at p < 0.05. Results: Tooth deproteinization increased the lightness by 4.8 AE 2.78, tooth demineralization resulted in 8.5 AE 5.68 decrease in the lightness and tooth oxidization induced 19.9 AE 6.58 increase in the lightness. Oxidization of the deproteinized teeth did not influence shade parameters, but oxidation of the demineralized teeth resulted in 10.7 AE 5.88 increase in the lightness. Conclusion: Hydrogen peroxide does not induce significant changes in tooth enamel organic and inorganic relative contents, and it whitens teeth just by oxidizing their organic matrix. These findings are of great clinical significance since they explain the mechanism of tooth bleaching, and help understanding its limitations and disadvantages.
The Journal of Contemporary Dental Practice, 2017
Aim The aim of the study was to evaluate the bleaching effect, morphological changes, and variations in calcium (Ca) and phosphate (P) in the enamel with hydrogen peroxide (HP) and carbamide peroxide (CP) after the use of different application regimens. Materials and methods Four groups of five teeth were randomly assigned, according to the treatment protocol: HP 37.5% applied for 30 or 60 minutes (HP30, HP60), CP 16% applied for 14 or 28 hours (CP14, CP28). Changes in dental color were evaluated, according to the following formula: ΔE = [(La−Lb)2+(aa−ab)2 + (ba−bb)2]½. Enamel morphology and Ca and P compositions were evaluated by confocal laser scanning microscope and environmental scanning electron microscopy. Results ΔE HP30 was significantly greater than CP14 (10.37 ± 2.65/8.56 ± 1.40), but not between HP60 and CP28. HP60 shows greater morphological changes than HP30. No morphological changes were observed in the groups treated with CP. The reduction in Ca and P was significantl...