Effects of different concentrations of carbamide peroxide and bleaching periods on the roughness of dental ceramics

Autor(es)

Morey Ourique, Sergio Augusto ; Galvao Arrais, Cesar Augusto ; Cassoni, Alessandra ; Ota-Tsuzuki, Claudia ; Rodrigues, Jose Augusto

• Tipo de documento: Artigo Científico
• Fonte: BRAZILIAN ORAL RESEARCH; v. 25, n. 5, p. 6-pg., 2011-09-01.

Resumo

The wide use of dental bleaching treatment has brought concern about the possible effects of hydrogen peroxide on dental tissue and restorative materials. The objective of this study was to evaluate in vitro the effect of nightguard bleaching on the surface roughness of dental ceramics after different periods of bleaching treatment. Fifteen specimens of 5 x 3 x 1 mm were created with three dental ceramics following the manufacturers' instructions: IPS Classic (Ivoclar-Vivadent); IPS d.Sign (Ivoclar-Vivadent); and VMK-95 (Vita). A profilometer was used to evaluate baseline surface roughness (Ra values) of all ceramics by five parallel measurements with five 0.25 mm cut off (lambda c) at 0.1 mm/s. Afterwards, all specimens were submitted to 6-h daily bleaching treatments with 10% or 16% carbamide peroxide (Whiteness- FGM) for 21 days, while control groups from each ceramic system were stored in artificial saliva. The surface roughness of all groups was evaluated after 18 h, 42 h, 84 h, and 126 h of bleaching treatment. The surface roughness of each specimen (n = 5) was based on the mean value of five parallel measurements in each time and all data were submitted to two-way repeated measures ANOVA and Tukey's post-hoc test (alpha = 0.05). No significant differences in ceramic surface roughness were observed between untreated and bleached ceramic surfaces, regardless of bleaching intervals or bleaching treatments. This study provided evidence that at-home bleaching systems do not cause detrimental effects on surface roughness of dental ceramics. (AU)

• Processo FAPESP: 07/03365-9 - Efeito de agentes clareadores sobre a microdureza de cerâmicas dentais
• Beneficiário: Jovana Pontes da Silva Magdaleno
• Modalidade de apoio: Bolsas no Brasil - Iniciação Científica
• Processo FAPESP: 04/01175-0 - Efeito in vitro e in situ de diferentes sistemas clareadores caseiros sobre a microdureza do esmalte dental humano e efetividade clínica
• Beneficiário: José Augusto Rodrigues
• Modalidade de apoio: Auxílio à Pesquisa - Regular