Effects of experimental bleaching agents on the mineral content of sound and demineralized enamels
Abstract High concentrations of hydrogen peroxide can cause adverse effects on composition and structure of teeth. However, the addition of calcium and fluoride in bleaching agents may reduce enamel demineralization. Objective: To evaluate chemical changes of sound and demineralized enamels submitt...
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| Format: | Article |
| Language: | English |
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University of São Paulo
2018-10-01
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| Series: | Journal of Applied Oral Science |
| Subjects: | |
| Online Access: | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-77572018000100497&lng=en&tlng=en |
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| author | Vanessa Cavalli Denise Aparecida da Rosa Daylana Pacheco da Silva Matheus Kury Priscila C. S. Liporoni Luis Eduardo S. Soares Airton Abraão Martins |
| author_facet | Vanessa Cavalli Denise Aparecida da Rosa Daylana Pacheco da Silva Matheus Kury Priscila C. S. Liporoni Luis Eduardo S. Soares Airton Abraão Martins |
| author_sort | Vanessa Cavalli |
| collection | DOAJ |
| description | Abstract High concentrations of hydrogen peroxide can cause adverse effects on composition and structure of teeth. However, the addition of calcium and fluoride in bleaching agents may reduce enamel demineralization. Objective: To evaluate chemical changes of sound and demineralized enamels submitted to high concentrations of hydrogen peroxide containing fluoride (F) or calcium (Ca). Material and Methods: Enamel blocks of bovine incisors with standard dimensions were obtained and half of them were submitted to pH-cycling to promote initial enamel caries lesions. Sound and demineralized enamel samples were divided into (n=10): (C) Control (no whitening treatment); (HP) 35% hydrogen peroxide; and two experimental groups: (HPF) 35% HP+0.2% F and (HPC) 35% HP+0.2% Ca. Experimental groups were submitted to two in-office bleaching sessions and agents were applied 3 times for 15 min to each session. The control group was kept in remineralizing solution at 37°C during the bleaching treatment. The surface mineral content of sound and demineralized enamels was determined through Fourier Transform Raman spectroscopy (FT-Raman), Energy dispersive Micro X-ray fluorescence spectroscopy (μ-EDXRF); and the subsurface, through cross-sectional microhardness (CSMH). In addition, polarized light microscopy (PLM) images of enamel subsurface were observed. Results: According to three-way (FT-Raman and μ-EDXRF analyses) or two-way analysis of variance (ANOVA) (CSMH) and Tukey test (α=5%), the calcium or fluoride added to high-concentrated bleaching agents increased phosphate and carbonate concentrations on sound and demineralized enamels (p<0.05). However, HPC and HPF were unable to completely reverse the subsurface mineral loss promoted by bleaching on sound and demineralized enamels. The calcium/ phosphate (Ca/P) ratio of sound enamel decreased after HP treatment (p<0.001). Conclusion: Even though experimental bleaching agents with Ca or F reduced mineral loss for both sound and demineralized enamel surfaces, these agents were unable to reverse the enamel subsurface demineralization. |
| first_indexed | 2024-12-11T09:49:06Z |
| format | Article |
| id | doaj.art-6e4d1597658744faab18b803d6464533 |
| institution | Directory Open Access Journal |
| issn | 1678-7765 |
| language | English |
| last_indexed | 2024-12-11T09:49:06Z |
| publishDate | 2018-10-01 |
| publisher | University of São Paulo |
| record_format | Article |
| series | Journal of Applied Oral Science |
| spelling | doaj.art-6e4d1597658744faab18b803d64645332022-12-22T01:12:28ZengUniversity of São PauloJournal of Applied Oral Science1678-77652018-10-0126010.1590/1678-7757-2017-0589S1678-77572018000100497Effects of experimental bleaching agents on the mineral content of sound and demineralized enamelsVanessa CavalliDenise Aparecida da RosaDaylana Pacheco da SilvaMatheus KuryPriscila C. S. LiporoniLuis Eduardo S. SoaresAirton Abraão MartinsAbstract High concentrations of hydrogen peroxide can cause adverse effects on composition and structure of teeth. However, the addition of calcium and fluoride in bleaching agents may reduce enamel demineralization. Objective: To evaluate chemical changes of sound and demineralized enamels submitted to high concentrations of hydrogen peroxide containing fluoride (F) or calcium (Ca). Material and Methods: Enamel blocks of bovine incisors with standard dimensions were obtained and half of them were submitted to pH-cycling to promote initial enamel caries lesions. Sound and demineralized enamel samples were divided into (n=10): (C) Control (no whitening treatment); (HP) 35% hydrogen peroxide; and two experimental groups: (HPF) 35% HP+0.2% F and (HPC) 35% HP+0.2% Ca. Experimental groups were submitted to two in-office bleaching sessions and agents were applied 3 times for 15 min to each session. The control group was kept in remineralizing solution at 37°C during the bleaching treatment. The surface mineral content of sound and demineralized enamels was determined through Fourier Transform Raman spectroscopy (FT-Raman), Energy dispersive Micro X-ray fluorescence spectroscopy (μ-EDXRF); and the subsurface, through cross-sectional microhardness (CSMH). In addition, polarized light microscopy (PLM) images of enamel subsurface were observed. Results: According to three-way (FT-Raman and μ-EDXRF analyses) or two-way analysis of variance (ANOVA) (CSMH) and Tukey test (α=5%), the calcium or fluoride added to high-concentrated bleaching agents increased phosphate and carbonate concentrations on sound and demineralized enamels (p<0.05). However, HPC and HPF were unable to completely reverse the subsurface mineral loss promoted by bleaching on sound and demineralized enamels. The calcium/ phosphate (Ca/P) ratio of sound enamel decreased after HP treatment (p<0.001). Conclusion: Even though experimental bleaching agents with Ca or F reduced mineral loss for both sound and demineralized enamel surfaces, these agents were unable to reverse the enamel subsurface demineralization.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-77572018000100497&lng=en&tlng=enTooth bleachingHydrogen peroxideFluoridesTooth remineralization |
| spellingShingle | Vanessa Cavalli Denise Aparecida da Rosa Daylana Pacheco da Silva Matheus Kury Priscila C. S. Liporoni Luis Eduardo S. Soares Airton Abraão Martins Effects of experimental bleaching agents on the mineral content of sound and demineralized enamels Journal of Applied Oral Science Tooth bleaching Hydrogen peroxide Fluorides Tooth remineralization |
| title | Effects of experimental bleaching agents on the mineral content of sound and demineralized enamels |
| title_full | Effects of experimental bleaching agents on the mineral content of sound and demineralized enamels |
| title_fullStr | Effects of experimental bleaching agents on the mineral content of sound and demineralized enamels |
| title_full_unstemmed | Effects of experimental bleaching agents on the mineral content of sound and demineralized enamels |
| title_short | Effects of experimental bleaching agents on the mineral content of sound and demineralized enamels |
| title_sort | effects of experimental bleaching agents on the mineral content of sound and demineralized enamels |
| topic | Tooth bleaching Hydrogen peroxide Fluorides Tooth remineralization |
| url | http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-77572018000100497&lng=en&tlng=en |
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