Aclaramiento Dental con Enjuagues de Libre Venta que Contienen Peróxido de Hidrógeno / Toothbleaching with over the Counter Mouthwashes Containing Hydrogen Peroxide

RESUMEN: El objetivo de este estudio in vitro fue evaluar la eficacia en el aclaramiento dental de tres enjuagues orales que contienen peróxido de hidrógeno en diferentes períodos de inmersión en comparación con el peróxido de carbamida al 10 %. Cuarenta muestras de premolares humanos se dividieron aleatoriamente en cuatro grupos según el agente al que se expuso: G1: Colgate Plax®Whitening, G2: Listerine®Whitening Extreme y G3: Oral B® 3D White™ se sumergieron dos minutos al día durante 28 días y G4: Peróxido de carbamida al 10 %, ocho horas al día durante 14 días. La medición de color se realizó con un espectrofotómetro Vita Easyshade usando la escala CIELab inicialmente, a los 14, 28 y 35 días de evaluación. Las comparaciones entre los grupos se realizaron utilizando las pruebas Kruskal-Wallis y U Mann-Whitney, mientras que entre los tiempos las pruebas Friedman y Signo-Rango de Wilcoxon. Los resultados revelaron que a los 14 días, los cuatro grupos mostraron cambios de color, pero no se evidenció mayor eficacia de alguno sobre el otro (p>0,05). Sin embargo, a los 28 y 35 días se observó una clara eficacia del peróxido de carbamida sobre los enjuagues (p<0,05). Los enjuagatorios orales aclaran los dientes a partir de los 28 días, con los protocolos indicados; sin embargo no llegan a tener resultados similares a un aclaramiento profesional con gel de peróxido de carbamida al 10 %.

ABSTRACT: The objective of this in vitro study was to evaluate the efficacy in dental toothbleaching of three mouthwashes containing hydrogen peroxide in different periods of immersion compared to 10 % carbamide peroxide. Forty samples of human premolars were randomly divided into four groups according to the agent to which they were exposed: G1: Colgate Plax®Whitening, G2: Listerine®Whitening Extreme and G3: Oral B® 3D White ™ were immersed two minutes a day during 28 days and G4: 10 % carbamide peroxide, eight hours a day for 14 days. The color measurement was performed with a Vita Easyshade spectrophotometer using the CIELab scale initially, at 14, 28 and 35 days of evaluation. The comparisons between the groups were made using the Kruskal-Wallis and U Mann-Whitney tests. While between the times the tests Friedman and Sign-Range of Wilcoxon. The results revealed that at 14 days, the four groups showed color changes, but no greater effectiveness was shown of one over the other (p>0,05). However, at 28 and 35 days a clear efficacy of carbamide peroxide was observed on the rinses (p<0,05). Mouthwashes clear the teeth after 28 days, with the indicated protocols; however, they do not reach similar results to a professional clarification with 10 % carbamide peroxide gel.

The effect of carbamide peroxide bleaching agents on the microhardness of dental ceramics

This study examined the effect of 10% and 16% carbamide peroxide bleaching agents on the surface microhardness of micro-particulate feldspathic ceramics (VM7 and VM13, Vita Zahnfabrik). Forty specimens (8-mm diameter, 2-mm thickness) were divided into four groups (n=10): G1- VM7 + 10% Whiteness, G2- VM7 + 16% Whiteness, G3- VM13 + 10% and G4- VM13 + 16% Whiteness. The home-use bleaching agents were applied for 8 hours on 15 days, and the specimens were stored in distilled water at 37°C. The Vickers hardness number (HV) was determined for each specimen. Data were analyzed by the Wilcoxon and Mann- Whitney tests (p<0.05). The microhardness values before exposure were: g1- 433 (57); g2- 486 (22); g3- 509 (28); g4- 518 (24), and after exposure: G1- 349 (32); G2- 496 (95); G3- 519 (38); G4- 502 (81). G2 exhibited a higher and significant difference than G1 in VM7 groups, and the effect of bleaching concentration was shown to be significant by the Mann-Whitney test. And for VM13, both the Wilcoxon and Mann-Whitney tests showed no significant differences. When using 10% carbamide peroxide, the microhardness of VM7 ceramic was affected, and there were no effect on the microhardness between VM7 and VM13 ceramics when 16% carbamide peroxide was used.

Este estudo examinou o efeito do agente clareador peroxido de carbamida a 10% e a 16% na microdureza superficial de ceramicas feldspaticas micro-particuladas (VM7 e VM13, Vita Zahnfabrik). Quarenta corpos-de-prova (8 mm de diametro, 2 mm de espessura) foram divididos em quatro grupos (n=10): G1- VM7 + 10% Whiteness, G2- VM7 + 16% Whiteness, G3- VM13 + 10% e G4- VM13 + 16% Whiteness. Os agentes clareadores foram aplicados por 8 horas durante 15 dias e os cp foram armazenados em agua destilada a 37°C. A dureza Vickers (HV) de cada cp foi determinada. Os dados foram analisados pelos testes de Wilcoxon e Mann-Whitney (p<0.05). Os valores da dureza antes da exposicao ao agente clareador foram: g1- 433 (57); g2- 486 (22); g3- 509 (28); g4- 518 (24), e depois da exposicao: G1- 349 (32); G2- 496 (95); G3- 519 (38); G4- 502 (81). G2 exibiu diferenca significante e microdureza maior comparado ao G1 nos grupos da VM7 e o efeito da concentracao do clareador foi significante, apresentados atraves dos testes Mann-Whitney. Para VM13, ambos testes, Wilcoxon e Mann-Whitney, nao apresentaram diferenca significante. Quando o peroxido de carbamida a 10% foi avaliado, a microdureza da ceramica VM7 foi afetada, e nao houve diferenca na microdureza entre as ceramicas VM7 e VM13 quando o peroxido de carbamida a 16% foi utilizado.