Why Doesn't Invisalign Smooth the Tray Edges?

Why are the edges not smoother, why would one develop 2 canker sores on the inside of the lower lip? Is this a quality control issue? Why must one whittle away at our trays with a nail file when they have paid $5,000 for a finished product?

Doctor Answers 6

Tray edge sharpness on Invisalign

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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.  

Rough edges

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There is 2 options to fix the problem. Your dentist either smooths  the margins with a special tool or if he or she cannot fix it, it needs to be sent back to the manufacturer to have the aligners reprocessed.

Antoaneta Barba, DDS
Santa Ana Dentist

Rough Invisalign trays are rare

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We have not had this complaint very often, if ever, but when it does happen it is likely a factor of the aligners being mass produced.  The majority of the manufacturing is automated, so human hands aren't involved very much.

On the rare exception that they are rough, the simple solution is to take an emory board or the like and adjust.  Great care should be taken so as to not weaken the aligner, but minor contouring should be safe.

If a part of quality control included having a human round each and every corner, the cost for Invisalign would be much higher than it is currently.  This would very likely lead to decreasing case acceptance and the technology would simply vanish.

Invisalign trays are rough

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Invisalign trays are manufactured with computer technology to assure your teeth will move to a new position. Since this is done with machines, you may have arough edge on a tray. We have found this to be rare. Your dentist can polish any rough edges you may feel.

Not Usually an Issue

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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. 

Gary Nack, DDS
Philadelphia Dentist

Definitely part of mass manufacturing but also due initial fit

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We definitely hear that the edges of the aligners can be slightly uncomfortable for out patients.  The issue is that if they are rounded off, they would likely have to be thicker.  Due to the angles at which pressure may need to be applied, the aligners may not be sitting right up against the teeth at the start of an aligner, but may change position as the teeth move.  No matter what, so long as there is some kind of step between the gums, teeth, and aligner, you will likely feel the edge.  It is important that the aligners don't sit right on the gums as to not cause gum recession.

The best way to deal with sharp aligners is to get a clean nail file and smooth out some of the rough edges.  This usually takes care of the problem without compromising any tooth movement  If you have concerns with this, please speak to your orthodontist.

Jason K. Tam, DDS
Toronto Orthodontist

These answers are for educational purposes and should not be relied upon as a substitute for medical advice you may receive from your physician. If you have a medical emergency, please call 911. These answers do not constitute or initiate a patient/doctor relationship.