Purpose: The aim of this in vitro study was to investigate the effectiveness of a novel charcoal-containing whitening toothpaste and a mouthwash on tooth color change and the alterations of enamel that may be induced after toothbrushing, corresponding to a 90-day period. Materials and Methods: Forty human canines were used, stained with coffee, and divided into four groups ( n = 10) as follows: Group 1 (control) submitted to toothbrushing with deionized water, Group 2 with a regular toothpaste, Group 3 with a whitening toothpaste (1% charcoal), and Group 4 with the same whitening toothpaste in combination with a mouthwash (1% charcoal and 0.5% H 2 O 2 ). After the treatments, ΔΕ of the teeth was evaluated using an ultraviolet/Vis spectrophotometer, whereas the changes in surface morphology were observed by means of a confocal microscope. Results: The whitening toothpaste increased significantly ΔΕ (40.5%) compared to the control group ( P < 0.001). In addition, the tested whitening toothpaste also increased ΔΕ (17.7%) compared to the regular toothpaste ( P = 0.023). The whitening toothpaste presented smoother surfaces after toothbrushing, but more heterogeneous with numerous large craters, whereas the whitening mouthwash did not influence surface morphology changes. Conclusions: Charcoal-containing toothpastes may enhance the whitening of the teeth, but they should be used carefully due to changes that may induce on enamel. The patients should consult a dental professional for proper use. A charcoal-containing mouthwash in combination with whitening toothpastes probably cannot offer additional whitening effect.

No abstract

Polymers from renewable feedstocks are receiving increasing attention as the awareness about environmental issues derived from petroleum exploitation and waste accumulation is growing. With unsaturated polyester resins being one of the most used classes of polymers worldwide, the utilization of biobased monomers for manufacturing is more relevant than ever. In the present work, succinic acid, one of the most promising biobased building blocks, was incorporated in the structure of the resins in question to increase their biobased content. By reacting with ethylene glycol (EG) or poly(ethylene glycol) and maleic anhydride (MA) at several molar rations, unsaturated polyester resins (UPRs) were prepared. Their synthesis was evaluated by a variety of spectroscopical techniques, and their rheological properties made use of the reactive diluent mandatory for facilitating processing. Thus, in a second stage acrylic acid (AA) was used as cross-linking agent in the present of initiators and accelerators producing thermosetting resins. Differential scanning calorimetry (DSC) was employed to screen the cross-linking procedure, whereas with X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) it was proven that thermosetting resins were prepared. The thermal stability of the cured materials was evaluated by thermogravimetric analysis (TGA).

No abstract

No abstract