Opalescence® PF take-home whitening gels produce brilliant smiles. The patented sticky, viscous formula keeps the gels in the tray longer for sustained whitening power. In addition, a unique combination of potassium nitrate and fluoride decrease sensitivity while also strengthening enamel and preventing cavities. Twenty percent water content helps prevent dehydration and relapse. The powerful gels are even successful at treating discoloration from fluorosis and tetracycline staining. Opalescence gels are available in syringes or unit-dose bulbs and come in a variety of concentrations and flavors.