Aim To evaluate the influence of the parameters L* a* b* on the variation of the color of bovine tooth enamel submitted to artificial darkening, after simulated brushing, with whitening toothpastes containing blue covarine. Methods To undertake this study in vitro, 60 specimens (SP) were divided into 6 groups (n=10): control group (CGwater) and 5 test groups (GT1-Colgate Total 12, GT2-Oral-B 3D White Perfection, GT3-Colgate Luminous Instant White, GT4-CloseUp White Diamond Attraction, GT5-Sorriso Xtreme White). The specimens were darkened with coffee and submitted to simulated brushing for 6, 12, and 24 months. The alteration in the color was evaluated using CIELAB parameters and the ∆L, ∆a, ∆b and ∆E were calculated. The data was analyzed through generalized linear models using the R program and considering a level of significance of 5%. Results The parameters L*, a* and the ∆L, ∆a obtained better results in the test group than in the control group. There were no statistical differences between CG and the test groups for the evaluation of the b* parameter. In the evaluation of the ∆b, the GT3 differed statistically from the CG. In relation to the ∆E, all the group tests showed a variation in color statistically greater than that of the CG and the GT4 showed the greatest variation, not differing from the GT3 during the periods studied. Conclusion The mechanical and optical whitening agents positively influenced the values L*a* and b*, as well as in its variations and in the ∆E. It is important to emphasize, however, that to analyze tooth whitening it is necessary to evaluate their parameters together.

Resumo Introdução O Blue covarine é um pigmento que promove alterações ópticas nas superfícies dentárias proporcionando o seu branqueamento. Objetivo Avaliar in vitro o efeito de dentifrícios branqueadores contendo Blue covarine em resina composta nanoparticulada submetida a escurecimento artificial. Material e método 160 corpos de prova (CPs) de resina composta nanoparticulada FILTEK Z350XT foram divididos aleatoriamente em dois experimentos: Experimento I- 8 grupos (n=10) submetidos a escovação com escova elétrica por 1 mês; Experimento II- 8 grupos (n=10) submetidos a escovação simulada por 6, 12 e 24 meses. Os grupos foram distribuídos de acordo com a solução/dentifrício testado: GC (água destilada) e 7 grupos teste (GT1-Coltene Herjos, GT2- Colgate Total 12 Clean Mint, GT3- Colgate Luminous White Brilliant Mint, GT4- Oral B 3D White Perfection, GT5- Close Up White Now Glacier Fresh, GT6- Close Up White Attraction Diamond e GT7- Sorriso Xtreme White Evolution). Resultado No experimento I, houve maior ∆E no GT6 com relação ao GC, GT2, GT4 e GT5, que não diferiram entre si. No experimento II, após 24 meses de escovação houve maior ∆E nos grupos GT6 e GT7. Após 24 meses de escovação simulada não houve alteração da rugosidade nem perda de massa em nenhum grupo. Conclusão O efeito branqueador promovido pelos dentifrícios contendo o agente Blue covarine parece estar relacionado à associação deste agente com os abrasivos presentes nas formulações dos dentifrícios branqueadores.

Abstract Introduction Blue covarine is a pigment that promotes optical changes in dental surfaces, providing whitening. Objective To evaluate in vitro the effect of bleaching dentifrices containing Blue covarine in nanoparticulate composite resin subjected to artificial darkening. Material and method One hundred sixty (160) specimens (PBs) of FILTEK Z350XT nanoparticulate composite resin were randomly divided into two experiments: Experiment I - 8 groups (n=10) submitted to brushing with an electric toothbrush for 1 month; Experiment II - 8 groups (n=10) submitted to simulated brushing for 6, 12 and 24 months. Groups were distributed according to the solution/dentifrice tested: CG (distilled water) and 7 test groups (GT1- Coltene Herjos, GT2- Colgate Total 12 Clean Mint, GT3- Colgate Luminous White Brilliant Mint, GT4- Oral B 3D White Perfection, GT5- Close Up White Now Glacier Fresh, GT6- Close Up White Attraction Diamond and GT7- Sorriso Xtreme White Evolution). Result In Experiment I, there was greater ∆E in GT6 in relation to CG, GT2, GT4 and GT5, with no differences among them. In Experiment II, after 24 months of brushing, there was greater ∆E in groups GT6 and GT7. After 24 months of simulated brushing, there was no change in roughness or loss of mass in any group. Conclusion The whitening effect promoted by dentifrices containing the agent Blue covarine seems to be related to the association of this agent with the abrasives present in the formulations of whitening dentifrices.

Resumo Introdução O blue covarine é um agente branqueador que promove mudanças ópticas na superfície dos dentes, associado aos abrasivos dos dentifrícios, colaborando para o branqueamento dentário. Objetivo Determinar as alterações de cor, rugosidade e massa do esmalte bovino, após escovação simulada com dentifrícios branqueadores contendo blue covarine nos tempos 6, 12 e 24 meses. Material e método 80 corpos de prova (CP) foram divididos em 8 grupos (n = 10): grupo controle (GC-água) e 7 grupos teste (GT1-Colgate Total 12, GT2-Oral-B 3D White Perfection, GT3-Colgate Luminous Instant White, GT4-Close Up White Diamond Attraction, GT5-Close Up White-Glacier Fresh, GT6-Sorriso Xtreme White, GT7-Colgate Luminous White Advanced). Os CP foram escurecidos com café e submetidos à escovação simulada por 6, 12 e 24 meses. As avaliações de cor, rugosidade e massa foram realizadas após cada período de escovação. Resultado Nenhum dentifrício teste promoveu alterações significativas na rugosidade e massa dos CP, contudo, quando comparados ao GC todos promoveram branqueamento significativo. A comparação dos grupos teste não demonstrou diferença significativa na variação de cor entre GT1, GT2, GT3, GT5, GT6 e GT7 nos tempos estudados. O GT4 apresentou comportamento variável de acordo com o tempo, não diferindo estatisticamente de GT3 aos 6, 12 e 24 meses, de GT6 aos 6 e 12 meses e de GT7 aos 12 meses. Conclusão O efeito branqueador dos dentifrícios contendo blue covarine , após 2 anos de escovação, parece estar relacionado principalmente com a sua associação aos agentes branqueadores mecânicos, que promoveram o polimento das superfícies dentárias.

Abstract Introduction Blue covarine is a bleaching agent that produces optical changes on the surface of the teeth, associated with the abrasives of the dentifrice leading to tooth whitening. Objective To determine the changes in colour, roughness and mass of the bovine enamel, after simulated brushing with dentifrices - containing blue covariate bleaching - for 6, 12 and 24 months. Material and method 80 specimens were divided into 8 groups (n = 10): Control group (CG-water) and 7 test groups (TG1-Colgate Total 12, TG2-Oral-B 3D White Perfection, TG3 -Colgate Luminous Instant White, TG4-Close Up White Diamond Attraction, TG5-Close Up White Now-Glacier Fresh, TG6-Sorriso Xtreme White, TG7-Colgate Luminous White Advanced). The specimens were stained with coffee and subjected to simulated brushing for 6, 12 and 24 months. The colour, roughness and mass evaluations were performed after each brushing period. Result No dentifrice test produced significant alterations in the roughness and mass of the specimens, however, when compared to CG, all of themproduced significant whitening. The comparison of the test groups did not show a significant difference in the colour variation between TG1, TG2, TG3, TG5, TG6 and TG7 in the study. The TG4 presented a variable behavior according to time, not statistically differing from TG3 at 6, 12 and 24 months, neither from TG6 at 6 and 12 months nor from TG7 at 12 months. Conclusion The whitening effect of dentifrices containing blue covarine, after long periods of brushing, seems to be related mainly to association with mechanical bleaching agents, which, despite abrasives, did not damage the dental structure.