Cast Gold Dental Post Technique

Today I learned how to make a cast post via the indirect technique (done extraorally) vs. via the direct technique (done intraorally) as it is done at the college.

Everything starts similarly in both scenarios: We use the Peeso reemers to open up the canal to make sure the walls are parallel or divergent occlusally without any undercuts. This design ensures that when taking an impression, the impression material does not get stuck in the canal. We leave about 7-8mm of gutta percha at the apex and rinse with sodium hypochlorite. Afterwards, we take a post system and try to fit the plastic post cones into the canal, making sure that the tip of the post system is in contact with the coronal part of the gutta percha. After this is achieved, we take an impression tray and  put some Impregum into it and at the same time we load the light body material into the canal of the tooth where the post system is. We leave it like this for 6 minutes and then we take it out and get our final result fast and efficiently.

I prefer to use the indirect method for making cast post over the direct method used at the college for several reasons: Reason number one is that the abovementioned method saves a lot of time if doing one post and especially if doing a few posts. The method that we use at the college to build up the plastic cast post cone with duralay is also reliable but it is very time consuming and it requires much more time when doing several teeth simultaneously. The second reason why I like this method is because it is easier to do than at the college if it is done properly. It is certainly easier to take one good impression with 6 different posts as shown below instead of building up all 6 plastic post cones with duralay.

However, there are a few things that need to be kept in mind when doing the indirect technique cast post method: First of all, when doing an impression of multiple posts one must make sure that the canals are prepared in such a way so that when taking the impression they all have a similar line of draw, that is they must be more or less parallel to one another. Second of all, one must make sure that all post cones have been inserted all the way down to the gutta percha before taking the impression in order not to have a gap that could potentially fill up with bacteria. Third of all, it is very important to know how to handle the impression material, when to bleed it, and the proper techniques for seating it and taking it off.

R.F., New York University College of Dentistry

Categorised in: Dental Student Experiences

This post was written by Interns