Evaluation of an experimental rat model for comparative studies of bleaching agents
ABSTRACT Dental materials, in general, are tested in different animal models prior to their clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents by investigating the influence of different concentrations a...
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2016-02-01
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doaj-cdd84496e5524289b060bf46580110bf2020-11-25T01:18:11ZengUniversity of São PauloJournal of Applied Oral Science1678-77652016-02-012419510410.1590/1678-775720150393S1678-77572016000100095Evaluation of an experimental rat model for comparative studies of bleaching agentsLuciano Tavares Angelo CintraFrancine BenettiLuciana Lousada FerreiraVanessa RahalEdilson ErvolinoRogério de Castilho JacintoJoão Eduardo Gomes FilhoAndré Luiz Fraga BrisoABSTRACT Dental materials, in general, are tested in different animal models prior to their clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats’ vital teeth. Material and methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals (control) were untreated. The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated by histomorphometric analysis with inflammatory cell counting in the coronal and radicular thirds of the pulp. The counting of fibroblasts was also performed. Scores were attributed to the odontoblastic layer and to vascular changes. The tertiary dentin area and the pulp chamber central area were histomorphometrically measured. Data were compared by the analysis of variance and the Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the occlusal third of the coronal pulp until the time of 15 min for both concentrations of bleaching gels. In 30 and 45 min groups of each concentration, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, a reduction in the pulp chamber central area and an enlargement of tertiary dentin area were observed without the detection of inflammation areas. Conclusion The rat model of extra coronal bleaching showed to be adequate for bleaching protocols studies, as it was possible to observe alterations in the pulp tissues and in the tooth structure caused by different concentrations and periods of application of bleaching agents.http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-77572016000100095&lng=en&tlng=enBleaching agentsAnimal modelsHydrogen peroxide |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Luciano Tavares Angelo Cintra Francine Benetti Luciana Lousada Ferreira Vanessa Rahal Edilson Ervolino Rogério de Castilho Jacinto João Eduardo Gomes Filho André Luiz Fraga Briso |
spellingShingle |
Luciano Tavares Angelo Cintra Francine Benetti Luciana Lousada Ferreira Vanessa Rahal Edilson Ervolino Rogério de Castilho Jacinto João Eduardo Gomes Filho André Luiz Fraga Briso Evaluation of an experimental rat model for comparative studies of bleaching agents Journal of Applied Oral Science Bleaching agents Animal models Hydrogen peroxide |
author_facet |
Luciano Tavares Angelo Cintra Francine Benetti Luciana Lousada Ferreira Vanessa Rahal Edilson Ervolino Rogério de Castilho Jacinto João Eduardo Gomes Filho André Luiz Fraga Briso |
author_sort |
Luciano Tavares Angelo Cintra |
title |
Evaluation of an experimental rat model for comparative studies of bleaching agents |
title_short |
Evaluation of an experimental rat model for comparative studies of bleaching agents |
title_full |
Evaluation of an experimental rat model for comparative studies of bleaching agents |
title_fullStr |
Evaluation of an experimental rat model for comparative studies of bleaching agents |
title_full_unstemmed |
Evaluation of an experimental rat model for comparative studies of bleaching agents |
title_sort |
evaluation of an experimental rat model for comparative studies of bleaching agents |
publisher |
University of São Paulo |
series |
Journal of Applied Oral Science |
issn |
1678-7765 |
publishDate |
2016-02-01 |
description |
ABSTRACT Dental materials, in general, are tested in different animal models prior to their clinical use in humans, except for bleaching agents. Objectives To evaluate an experimental rat model for comparative studies of bleaching agents by investigating the influence of different concentrations and application times of H2O2 gel in the pulp tissue during in-office bleaching of rats’ vital teeth. Material and methods The right and left maxillary molars of 50 Wistar rats were bleached with 20% and 35% H2O2 gels, respectively, for 5, 10, 15, 30, or 45 min (n=10 rats/group). Ten animals (control) were untreated. The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated by histomorphometric analysis with inflammatory cell counting in the coronal and radicular thirds of the pulp. The counting of fibroblasts was also performed. Scores were attributed to the odontoblastic layer and to vascular changes. The tertiary dentin area and the pulp chamber central area were histomorphometrically measured. Data were compared by the analysis of variance and the Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the occlusal third of the coronal pulp until the time of 15 min for both concentrations of bleaching gels. In 30 and 45 min groups of each concentration, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, a reduction in the pulp chamber central area and an enlargement of tertiary dentin area were observed without the detection of inflammation areas. Conclusion The rat model of extra coronal bleaching showed to be adequate for bleaching protocols studies, as it was possible to observe alterations in the pulp tissues and in the tooth structure caused by different concentrations and periods of application of bleaching agents. |
topic |
Bleaching agents Animal models Hydrogen peroxide |
url |
http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-77572016000100095&lng=en&tlng=en |
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