The whitening gel is safe, but potent, and has high levels of hydrogen peroxide. The Glen Dental Center uses targeted laser light to activate the tooth bleaching power for immediate lightening of enamel and dentin. Although over-the-counter whiteners may improve the color of teeth, they can take weeks or even months to show results, and even then the results are usually very temporary. Teeth can be whitened up to twelve shades in just under an hour! So many people are choosing to improve their smiles with this whitening treatment. Although most patients make great candidates for this procedure, it is not recommended for patients under age 18 or women who are pregnant or breast feeding.