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.