The Effect of Delivery System and Light Activation on Tooth Whitening Efficacy and Hydrogen Peroxide Penetration.

ABSTRACT Purpose To evaluate the whitening efficacy of a new two-layer technology in-office system compared to a conventional gel-type system and determine hydrogen peroxide penetration (HPP) into the pulp cavity. Materials and Methods Extracted molars ( n = 60) were assigned to group NC: glycerol gel; group QPRO: 20% HP varnish (Zoom Quick Pro, Philips Oral Healthcare); group ZOOM_NL: 25% HP gel (Zoom Chairside Whitening); and group ZOOM_WL: 25% HP gel (Zoom Chairside Whitening) with light-activation. HPP levels were estimated with leucocrystal-violet and horseradish-peroxidase. Instrumental color measurements were performed at baseline ( T0), 1-day post first whitening ( T1), 1-day post second whitening ( T2), 1-day post third whitening ( T3), and 1-month post whitening ( T4). One-way analysis of variance followed by post hoc Tukey's HSD test was performed to detect difference in Δ E* and HP penetration levels (α = 0.05). Results Δ E* of NC was lower than other groups, whereas Δ E* of ZOOM_WL was greater than the other three groups, at T3 and T4. Mean HPP level obtained from ZOOM_WL (1.568 ± 0.753 μg/mL) was significantly greater than those obtained from the other groups, whereas the mean HPP level observed in NC group (−0.131 ± 0.003 μg/mL) was significantly lower than the other groups. Conclusions Tooth whitening efficacy and HPP levels vary based on whitening systems used. CLINICAL SIGNIFICANCE The two-layer technology in-office varnish system may be an alternative whitening option to reduce chair time in the office. (J Esthet Restor Dent 28:313-320, 2016) [ABSTRACT FROM AUTHOR]