The whitening effect of single brushing with blue-covarine containing toothpaste-A randomized controlled trial

To evaluate whether a blue covarine containing silica-based toothpaste promotes a whitening effect immediately after tooth brushing.

A triple-blind, parallel group, randomized design was used to compare the tooth color before and after brushing. Two silica-based toothpastes were chosen, one of them containing blue covarine (BCT) and the other one without pigment to serve as control (CT). Tooth color was measured using a spectrophotometer and expressed as CIEDE 2000 ΔE, CIELAB values, WIO index, WI_D index and VITA scale tooth shade. In addition, the participants' satisfaction with and perception of their own tooth color were registered using an aesthetic numeric analogue scale.

No significant changes in color components or dimensions measured using CIEDE 2000 ΔE (CT: mean = 1.3, 95% CI 0.8, 1.7; BCT: mean = 1.6, 95% CI 1.2, 2.1), WIO, WI_D, VITA scale or CIELAB values were detected for the CT and BCT groups, comparing the results before and after brushing. Likewise, the participants' satisfaction with the treatment results (P = 0.31) and the participants' evaluation of tooth color (P = 0.71) did not differ significantly between groups.

After a single application, no significant improvement in tooth whiteness by the presence of blue covarine in a silica-based toothpaste was detected in color dimensions or by assessing the participants' satisfaction and perception.

The present study does not show a clinically relevant increase in tooth whiteness after a single brushing with a blue covarine containing toothpaste, nor could the study participants observe a difference between treatment with blue covarine containing toothpaste and control treatment.