I had a treatment with the light 10 years ago, it was one time and it's still good. I was thinking of buying this for a friend, not sure why multiple treatments are available since mine only took once and hasn't dulled at all in those years?
james b. asked on Sep 27, 2013
You get immediate results after one treatment, but your teeth will get whiter with each subsequent treatment.
tony R. from Groupon replied on Oct 2, 2013