|Year : 2012 | Volume
| Issue : 2 | Page : 57-60
Element analysis of enamel surface before and after bleaching using three modes of activation
Sucheta Sathe, Rateesha Bawa, Vivek Hegde
Department of Conservative Dentistry and Endodontics, M. A. Rangoonwala Dental College and Research Centre, Pune, Maharashtra, India
|Date of Web Publication||31-Jan-2013|
Department of Conservative Dentistry and Endodontics, M.A Rangoonwala Dental College and Research Centre, Pune
Source of Support: None, Conflict of Interest: None
Aim: The purpose of this study was to compare the element content in enamel surface before and after bleaching with two different bleaching agents using three modes of activation. Materials and Methods: Thirty human extracted central incisors were randomly divided into two groups based on the bleaching agents and were further subdivided into three subgroups based on the mode of activation as follows. The crowns of the teeth were demarcated into two halves vertically; one half serving as control while the other half is the bleached surface. Following bleaching, the samples are to be subjected to elemental analysis using EDAX software. Results : Using analysis of variance (ANOVA) tests it can be concluded that despite different bleaching agents with different concentration used, there was no overall significant difference between the element content before and after bleaching. Conclusion: Lasers showed a better performance than halogen light cure unit in terms of surface effects and elemental content.
Keywords: Bleaching,lasers,EDAX software
|How to cite this article:|
Sathe S, Bawa R, Hegde V. Element analysis of enamel surface before and after bleaching using three modes of activation. J Dent Lasers 2012;6:57-60
|How to cite this URL:|
Sathe S, Bawa R, Hegde V. Element analysis of enamel surface before and after bleaching using three modes of activation. J Dent Lasers [serial online] 2012 [cited 2020 Apr 4];6:57-60. Available from: http://www.jdentlasers.org/text.asp?2012/6/2/57/106655
| Introduction|| |
Tooth bleaching was first described in 1848 using chloride of lime. The use of hydrogen peroxide (H 2 O 2 ) to bleach the teeth was later introduced in 1888. In 1918, Abbot described the chairside bleaching method, as it is known today, using 35% H 2 O 2 together with heat and light to boost the oxidation reaction.  Since the early 1980s, the heat lamp and heated spatula have been used as a heat source to accelerate the bleaching process of concentrated H 2 O 2 . Various devices at different wavelength spectra and radiation energies, such as halogen, light emitted diodes (LEDs), diode lasers, argon lasers, and plasma arc lamps have been used in this regard.
H 2 O 2 is the main active ingredient of bleaching agents and the whitening effect it produces is due to its low molecular weight and its ability to penetrate through enamel and dentin. The basic process involves oxidation and reduction reactions that convert organic pigments into carbon dioxide and water. ,
The bleaching gel should absorb the light, and the tooth structure, in contrast, should be minimally affected. Therefore, photo-initiators or dyes are incorporated, which are adjusted to absorb the wavelength of the light source used. Although dental hard tissues are highly mineralized, their element content can play an important role in the bleaching process. It is speculated that the reaction between peroxide and the elements on the surface or in the subsurface of enamel can result in alteration. 
| Aim|| |
To compare the element content in surface before and after bleaching with two different bleaching agents using three modes of activation (Nd: YAG laser, Diode Laser, and light cure unit).
| Materials and Methods|| |
Thirty extracted single rooted human teeth were selected and randomly divided into two groups based on the bleaching agent used as follows (n = 15):
Group 1 - Pola office bleaching agent
Group 2 - JW power bleaching agent
These groups were further divided into three subgroups each based on mode of activation as follows (n = 5):
Subgroup A - light cure (3 cycles for 30 s each).
Subgroup B - diode laser (3 cycles for 30 s each at 2 W and 20 Hz).
Subgroup C - Nd: YAG laser (3 cycles for 30 s each at 20 Hz and 2 W).
The crowns of the teeth were demarcated into two halves vertically; one half serving as control while the other half is the bleached surface. The vertical half serving as control was sealed using transparent matrix band to prevent any contamination of the surface with the bleaching agent. Following bleaching the samples were subjected to EDAX analysis using ESEM.
| Observation|| |
Following images were obtained once the samples were subjected to analysis [Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6].
|Figure 1: Elemental analysis of pola office using light cure activation (a) control (b) bleached surface|
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|Figure 2: Elemental analysis of pola office using Diode laser activation (a) control (b) bleached surface|
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|Figure 3: Elemental analysis of pola office using Nd:YAG laser activation (a) control (b) bleached surface|
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|Figure 4: Elemental analysis of JW power bleach using light cure activation (a) control (b) bleached surface|
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|Figure 5: Elemental analysis of JW power bleach using diode laser activation (a) control (b) bleached surface|
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|Figure 6: Elemental analysis of JW power bleach using Nd:YAG laser activation (a) control (b) bleached surface|
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| Results|| |
The values obtained were subjected to statistical analysis using ANOVA test [Graph 1-3 [Additional file 1] [Additional file 2] [Additional file 3]].
| Discussion|| |
Effects of bleaching agents on enamel surface have been in discussion recently. When considering in-office bleaching agents, controversial results have been reported. Bleaching agents cause superficial structural changes to dentin and enamel and the acid pH probably produces an acid etch effect on dentin, increasing its permeability.  Concentrated 30-35% solutions of H 2 O 2 can also reduce the microhardness of enamel and dentin.
Studies , have indicated that immediately following bleaching the pH may fall to as low as 4 resulting in enamel diminerlization, thus making it more susceptible to caries attack. The transient low pH is proportional to the amount of free radicals generated. , Light irradiation and heat accelerates this reaction and thus the concentration of bleaching agent used and intensity and duration of the light source used effects the outcome of the same. Ruse et al. showed that in bleached enamel, the calcium/phosphate ratio is altered by 30-35% peroxide treatment.
McCracken and Haywood have shown loss of calcium in teeth exposed to peroxide.  Rotstein et al., observed lower fracture resistance and higher solubility of dental hard tissues after bleaching procedures, possibly due to modification of the organic and inorganic ratio of the tissues. Rodrigues et al., have shown that saliva and fluoride ions present in oral care substances are essential to equilibrate the demineralization and remineralization processes.
In the present study, regardless of the whitening product used, bleaching agents showed similar performance in both enamel elemental analysis, although the products present different bleaching regimen, composition and peroxide concentration. EDAX evaluation revealed elemental alterations in enamel after all bleaching procedures, irrespective of the activation mode used. Laser-activated bleaching, however, offered an improvement in terms of effectiveness and enamel element content.
| Conclusion|| |
Thus, within the limits of this study it may be concluded:
Despite different bleaching agents with different concentration used, there was no overall significant difference between the element content before and after bleaching.
Lasers showed a better performance than halogen light cure unit in terms of surface effects and elemental content.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5], [Figure 6]