Why Doesn't Invisalign Smooth the Tray Edges?

We periodically have a problem with sharp trays but it has been minor, and we have always been able to smooth the border with an emery board.  If the borders of multiple trays are extremely rough there may be a manufacturing problem or a distorted impression may have caused an incorrect set of trays to be created.  Talk to your dentist and have him call Invisalign to trouble shoot.  They have always been very concerned and helpful in fixing any problems.  They really seem to care about their product.  

It is not uncommon for areas of minor irritation to develop especially when a new tray is placed.  As was mentioned by Dr. Tam, simply filing the area gently with a nail file should help to alleviate the problem.  If you are not comfortable with that, then return to your dentist for an adjustment.  Unfortunately the trays are too thin to roll the edges so occasionally an irritation results from a sharp area that is not flush with the tooth.  I have found that in most cases, this occurs early in the case and as the case progresses, the problem area resolves.  Most patient are very tolerant of this and understand that this occasional area of irritation pales in comparison to the irritations that occur with conventional orthodontics.