The Teeth Whitening Pen is working! I’ve had the pen that arrived before two Dental Calculus Remover and as a former now retired Dental Assistant I used to whiten patients teeth with a cost of $300. I was curious so I ordered the pen and used it to whiten my two natural teeth on the sides of my dental implant. The shade on my implant is a A1 which is the whitest shade however, the two other natural teeth were a slightly different darken shade. I used the pen four times as of Sunday 3/7/21 and the natural teeth now match the dental implant tooth which is in upper front quadrant of my mouth. Nice product and quality pen that does whiten and all you need is 30 minutes a day for a lighter shade and a matching, whiter teeth.