PURPOSE The purpose of this study was to evaluate changes in calcium and phosphorus content in dental enamel when subjected to "in-office" whitening for an extended time by using a 35% hydrogen peroxide solution, with and without calcium. MATERIALS AND METHODS 10 human teeth, from which the roots had been removed, were embedded in epoxy resin, and their surfaces were smoothed. The specimens w...

Pitch shifting in speech is presented based on the use of the phase vocoder in combination with spectral whitening and envelope reconstruction, applied respectively before and after the transformation. A band preservation technique is introduced to contain quality degradation when downscaling the pitch. The transposition ratio is fixed in advance by selecting analysis and synthesis window sizes...

The conventional l2 multi-burst (MB) channel estimation can achieve the Cramér-Rao bound asymptotically by using the subspace projection. However, the l2 MB technique suffers from the noise enhancement problem if the training sequences (TSs) are not ideally uncorrelated. We clarify that the problem is caused by an inaccurate noise whitening process. The l1 regularized MB channel estimation can,...

A modification to the OE IIR system structure is proposed to ensure global convergence for sufficient modeling of the unknown system. The proposed structure is effectively equivalent to whitening the input signal before being applied to the original OE setup. This guarantees the unimodality of the error surface for sufficient modeling. An adaptive update scheme for the new structure is derived ...

In this work, a geometric invariant curve and surface normalization method is presented. Translation, scale and shear are normalized by Principal Component Analysis (PCA) whitening. Independent Component Analysis (ICA) and the third order moments are then employed for rotation and reflection normalization. By applying this normalization, curves and surfaces that are related by geometric transfo...

Objective: The purpose of this study was to evaluate the effects of application of three over the counter whitening toothpastes (Colgate Optic White, Aquafresh Ultimate White and Crest 3D White) on the color stability of different esthetic restorative materials (Resin composite/Filtek Z250 XT, resin modified glass ionomer/GC Fuji II LC, and glass ionomer/Ketac Molar Quick Aplicapweek) commonly ...

OBJECTIVES To evaluate the influence of different whitening protocols on the efficacy of 35% hydrogen peroxide (HP) tooth whitening and gel pH and concentration. MATERIAL AND METHODS Eighty-four enamel/dentin discs from bovine incisors were used. The baseline color was measured with a spectrophotometer. Two sessions of in-office whitening with 35% HP were performed under different protocols: ...

OBJECTIVE This study examined whether an ultraviolet light enhanced the whitening efficacy of a peroxide gel containing a photo-Fenton activator. METHODOLOGY Fifty subjects were enrolled into the trial at two geographically separate sites. As directed by the randomization keys, teeth of half of the study subjects were concurrently exposed to the whitening lamp, while the gel was on their teet...