How are Invisalign Impressions taken?

Up until very recently, there was only one way to take the necessary impressions for Invisalign, which was to use a material called PVS (polyvinylesiloxane).  This material captures great deal of the teeth and is stable over time (remember - your impressions have to be couriered to California).   This impression material needs to stay in the mouth anywhere from 2-4 minutes.  It will have to be repeated twice, once for the upper and once for the lower teeth. 

Orthodontists who typically have a good amount of experience will be able to tell if the impression is satisfactory or if a new one needs to be taken. 

An alternate method to taking the impressions which has recently been introduced, is the use of a 3D intra-oral scanner using the iTero scanner (which is now owned by Invisalign).  This scanner captures the contour of all the teeth.   The scanning usually takes about 10-15 minutes. 

Impressions must always be taken using PVS impression material which stands for polyvinylsiloxane.  This is an accurate impression material that allows us to exactly duplicate the tooth structure of each individual patient.  Impression material must sit in the mouth for about four to five minutes for each arch and then we have an accurate representation of the patient’s dental anatomy.
There is a new technology that has been currently developed today to where we can actually take a digital scan of the patient’s occlusion, and from here we are able to construct the Invisalign aligners for the patient.  Currently, these digital scanners require about 10 minutes of scanning the teeth to be able to have an accurate representation.
 

ITero is a digital scanner that basically takes 3D pictures of the teeth, or traditional goopy impression material for impressions.  Determining if they were good or not at that time depends on the the skill of the dentist, but MOST dentists should be able to tell right then.

However, a good impression does NOT guarantee that the case is good for Invisalign.  That is often determined with the special computer software, the ClinCheck.  Some cases are better served with traditional brackets and wires.

Invisalign impressions are taken with very accurate impression material.  These materials reproduce minute details of teeth.  Your dentist will be able to recognize deficiencies in the impression.  However, sometimes there are distortions that can't be picked up by the naked eye and may be found after processing.

As an interesting aside, Invisalign is introducing digital scanning to make the process even faster.  Now impression material is not needed, rather the teeth are scanned into a computer and an Invisalign model of the teeth is built in real time, this alleviates the concern over distortions.  This method will be even more accurate than the current impression materials.  The scanner is called ITero and will be introduced in the fall of 2011.

Cheers,

At your invisalign impression visit, I am going to assume that you already had your xrays and examination, they will take a mold of your top teeth and bottom teeth as well as photos of your mouth.  The dentist or dental assistant will know right away if the impression were ok. 

Invisalign impressions are taken by a thoroughly trained orthodontic assistant. These assistants have had numerous hours of training in order to achieve highest quality impressions with minimal discomfort to the patient. There are multiple different techniques used, however, the end goal is the same: crisp margins, detailed edges showing, material adhesion is excellent, and all dental anatomy present. In our office, our certified orthodontic assistant is able to visually inspect quality, then have it approved by the orthodontist.  She has completed invisalign continuing education in order to deliver perfect impressions and minimize re-impressions. If done correctly, there is no need for a second impression.

It is very important that the impressions taken for Invisalign are very accurate, or else they will need to be retaken, which will delay treatment, or they may not fit or move teeth correctly.  That said, it is not a difficult processs, and your treatment provider should be able to tell immediately if they are accurate enough, or if they need to be retaken.  It is usually a simple two step process, with two types of material used to get the detail captured that is necessary.  Many dentists have different methods, but if they are Premier or Elite providers of Invisalign, they will know exactly what to do to make the process as easy as possible.