Impression Post

An impression post is an aid in implant molding. A distinction is made between two different implant molding techniques, pickup and repositioning.

There are different kinds of impression posts, on the left you can see the two-part impression post used in pickup and on the right the post used in repositioning.

Pickup is the more precise of the two techniques, but it requires more effort on the part of the dentist. The differences between the two techniques will be illustrated by a short film.

Here you can see a patient after successful implantation. The patient was involved in an accident in which her front teeth and part of her jaw bone were knocked out. She did not want the missing piece of jaw-bone to be reconstructed, as appearances were not that important to her. However, the gums in that area were reinforced by a connective tissue transplant, to compensate for the loss at least to some extent.

Now you can see the affected area after the stitches have been removed and before the imprint has been taken – the temporary denture has been removed, exposing the gum or gingiva formers. These caps help the gums to heal after successful implantation has been performed. The gingiva formers are then removed.

First you will see the pickup technique, the corresponding impression posts are positioned over the implant and screwed into place. Impression posts have to fit perfectly, otherwise the dental technician produces a faulty crown.

Now the impression spoon needs to be fitted, or customized – an opening is cut for the shaft screw – in this case 2 holes were cut, so that the screws can be loosened and then removed after the imprint dries. This is the only way to get the impression posts of the implant out along with the imprint. The impression posts thus remain in the imprint when the impression spoon is removed.

You can now see the impression spoon being filled with a casting compound, a nozzle is used to spread some of the casting compound around the impression posts, in order to make the impression posts stick to the imprint and not move around. Once the casting compound has dried the shaft screw is loosened and the imprint removed along with the impression posts.

The impression posts thus remain in the impression spoon, in contrast to the repositioning technique. Here you can see a short animation, in which it is easy to see the implant, and how an impression post is screwed onto it for the repositioning technique. The impression spoon does not need to be customized, since the impression post stays in the mouth, and only after the imprint is removed is a post unscrewed from the implant and repositioned in the imprint, hence the name. All this repositioning, however, may lead to warping in the imprint, and although the repositioning imprint requires less work on the part of the dentist, the results of this technique are less precise.