Can whitening gel cause a recession of gum lines?

Bleaching materials themselves never are the cause of recession.However, recession and bleach sitting on recessed areas is the most cause of post- bleaching sensitivity.In office bleaching requires that recessed areas are blocked out from the gel touching them.If you are using trays from your dentist, have them look at them or remake to keep gel away.Over the counter strips can touch recession and cause pain, and are very difficult to keep away.Lastly, you may not have even noticed the recession until you began to bleach.  If it doesn't hurt or is not obvious before, you may not have even noticed until you got some sensitivity in the area.

The advised technique using bleaching gels is for them NOT to be in contact with your gums. So if your teeth bleaching get didn't get onto your gums, and you did the technique properly, I doubt that it caused your recession.Most trays used with take home bleaching don't go onto the gums either. If yours does, suggest returning to your dentist to have him trim off the extra plastic that goes onto your gums.