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Microhardness and roughness of enamel bleached with 10% carbamide peroxide and brushed with different toothpastes: an
Carolina França de Medeiros Melo1, Fernanda Borguetti Manfroi2, Ana Maria Spohr3
1Researcher, Department of Restorative Dentistry, School of Dentistry, Pontifical Catholic University of Rio Grande do Sul, Brazil.
Background:
This in situ study evaluated the roughness and microhardness of enamel bleached with 10% carbamide peroxide (PC10) and brushed with different toothpastes.
Materials And Methods:
Two groups of volunteers received PC10 and placebo agents for 21 days in two phases in a crossover 2 × 3 study. Fragments of human enamel were distributed among intraoral removable appliances (IRA). Nine fragments, divided into three triplets, were used in each IRA, and these were brushed with toothpastes R (Colgate), W (Colgate Total 12 Whiteness Gel) or BS (Colgate Whitening Oxygen Bubbles Fluoride). Treatments agents were applied for 8 h overnight. After brushing, the volunteers used the IRA for about 16 h/day. After a washout period, new IRAs were distributed and the volunteers were crossed over to the alternate agent for 21 days. Roughness and microhardness were measured before and after each phase.
Results:
According to the paired Student's t-test, roughness of enamel increased and microhardness decreased (P < 0.05). According to analysis of variance generalized linear models, only the toothpaste factor was significant (P = 0.037) for roughness.
Conclusion:
Enamel microhardness and surface roughness are altered when PC10 bleaching is associated with tooth brushing using toothpastes BS, R, and W.
