Evaluation of an experimental rat model for comparative studies of bleaching agents

Autor(es)

Angelo Cintra, Luciano Tavares ^[1] ; Benetti, Francine ^[1] ; Ferreira, Luciana Louzada ^[1] ; Rahal, Vanessa ^[2] ; Ervolino, Edilson ^[3] ; Jacinto, Rogerio de Castilho ^[1] ; Gomes Filho, Joao Eduardo ^[1] ; Fraga Briso, Andre Luiz ^[2]

Afiliação do(s) autor(es)

^[1] Univ Estadual Paulista, UNESP, Fac Odontol Aracatuba, Dept Endodontia, Aracatuba, SP - Brazil

^[2] Univ Estadual Paulista, UNESP, Fac Odontol Aracatuba, Dept Odontol Restauradora, R Jose Bonifacio 1193, Aracatuba, SP - Brazil

^[3] Univ Estadual Paulista, UNESP, Fac Odontol Aracatuba, Dept Ciencias Basicas, Aracatuba, SP - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Applied Oral Science; v. 24, n. 2, p. 171-180, MAR-APR 2016.
• Citações Web of Science: 3

Resumo

ABSTRACT Dental materials in general are tested in different animal models prior to the 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 were untreated (control). The rats were killed after 2 or 30 days, and the maxillae were examined by light microscopy. Inflammation was evaluated through histomorphometric analysis with inflammatory cell count in the coronal and radicular thirds of the pulp. Fibroblasts were also counted. Scores were attributed to odontoblastic layer and vascular changes. Tertiary dentin area and pulp chamber central area were measured histomorphometrically. Data were compared by analysis of variance and Kruskal-Wallis test (p<0.05). Results After 2 days, the amount of inflammatory cells increased in the coronal pulp occlusal third up to the 15-min application groups of each bleaching gel. In the groups exposed to each concentration for 30 and 45 min, the number of inflammatory cells decreased along with the appearance of necrotic areas. After 30 days, reduction on the pulp chamber central area and enlargement of the tertiary dentin area were observed, without the detection of inflammation areas. Conclusion The rat model of extracoronal bleaching showed to be adequate for studies of bleaching protocols, as it was possible to observe alterations in the pulp tissues and tooth structure caused by different concentrations and application periods of bleaching agents. (AU)

• Processo FAPESP: 11/13709-2 - Influência do número de sessões de clareação sobre a polpa dentária de ratos Wistar
• Beneficiário: Francine Benetti
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 13/25429-0 - Presença de caspase, PCNA e CD5 em polpas de ratos submetidos ao tratamento clareador com peróxido de hidrogênio em diferentes concentrações: estudo histológico e imunoistoquímico
• Beneficiário: Francine Benetti
• Modalidade de apoio: Bolsas no Brasil - Mestrado