Hello Teeth whitening is relatively safer, but the thing is whitening is never permanent as teeth can go back to yellowish color after six months to a year based on your eating habits. Teeth whitening is done by  hyfrogen peroside and yes it is also used for doing facial bleaching. The teeth is also actually bleached by this procedure but is temporary so try to do only for occasions . So if you want to have permanent whitening it is best to put Cermaic laminates on your front teeth. Hope my answer helps. Thank you.