Evaluation of a new silica whitening toothpaste containing blue covarine on the colour of anterior restoration materials in vitro

Objectives: The aims of this study were to evaluate the effects of a novel silica-based blue covarine whitening toothpaste on the colour of anterior restoration materials. Methods: Restoration materials (three glass ionomers, three resin composites) were cast into disks (10 mm diameter, 2 mm thick) using cylindrical moulds. Specimens were immersed in pooled whole saliva prior to exposure to staining materials via one of two protocols. CIELAB colour measurements were taken at baseline and after each stage of the procedures. In one protocol, specimens were brushed with 10 ml of 33% (w/w) silica whitening toothpaste containing blue covarine slurry in water four times, for 10 min each time, with control specimens being immersed in water or red wine for the same period. Disks were re-immersed in saliva for 2 h between cycles. In the other protocol, specimens were immersed in 20 ml of water, red wine or silica whitening toothpaste containing blue covarine slurry for 96 h with colour measurements being taken afterwards. The second protocol disks were then brushed for 2 min using a non-whitening silica paste and further colour measurements made. Colour differences were then calculated. Results: At the end of both protocols the disks treated with silica whitening toothpaste containing blue covarine were not significantly different from the water controls (p > 0.1) in contrast to those treated with red wine. Even prior to brushing in the second protocol, there was no significant staining from the new toothpaste compared to the water control (p > 0.1). Conclusions: There was no significant staining by the silica whitening toothpaste containing blue covarine on any of these materials. (c) 2008 Elsevier Ltd. All rights reserved.