Effectiveness of changing the color of darker teeth is potentiated by the association with violet LED light.

BACKGROUND: The effectiveness of in-office bleaching protocols performed with violet LED light either combined with a bleaching agent containing 37% carbamide peroxide, or not, was determined by comparing teeth with different degrees of darkening.

METHODOLOGY: Eighty bovine incisors were separated into groups of "light" teeth (luminosity greater than or equal to B3) and "dark" teeth (less than or equal to A3.5) to receive the protocols: HP - 35% hydrogen peroxide (Whiteness HP), CP - 37% carbamide peroxide (Whiteness SuperEndo), LED - violet LED light (Bright Max Whitening), CPLED - CP associated with the LED. For color analysis the CIEL*a*b* e WID , ΔEab , ΔE00 e ΔWID parameters were used. Data were analyzed using Mann-Whitney, Kruskal-Wallis, Dunn, Friedman or Nemenyi tests (α = 5%).

RESULTS: HP and CP resulted in similar color change values (ΔEab , ΔE00 e ΔWID ) for light and dark teeth (p>0.05). Dark teeth showed better bleaching effectiveness (ΔEab , ΔE00 e ΔWID ) than light teeth when CPLED was used (p<0.05). LED showed color change that were below the limits of acceptability and perceptibility for ΔWID .

CONCLUSION: light teeth are effectively bleached with the use of HP or CP, whereas dark teeth respond better to treatment with the CPLED protocol. Violet LED used alone did not show a satisfactory result.