Do NOT purchase this crap!!! I am a Dental Hygienist and I am telling you this pen is only worth about $5. We use it in the dental profession to SLIGHTLY lighten a tooth that may be a shade or 2 darker than the rest, and that is all. Also what people need to understand is that in order for there to be a signifigant change in tooth color we aim for around at least 7 shades of difference. one or 2 shades is NOTHING. Also they claim that Dazzlewhite will change the color of crowns, veneers and tooth colored fillings, It will NOT, there is not... read full review »