In this short video (6.38), Dr. Richard Price, Professor and Head of Fixed Prosthodontics in the Department of Dental Clinical Sciences at Dalhousie University’s Faculty of Dentistry, demonstrates a technique for cementing a Rely-X post and building up a core foundation prior to the restoration of an endodontically treated tooth
- From the radiograph or from the endodontic treatment notes, estimate the desired length of the post after leaving 5 mm of Gutta Percha at the apex.
- Prepare canal to the correct post length. Save as much of the root and tooth structure as you can.
- Choose a size of post that either just fits all the way to the correct length, or is 1 to 2 mm short.
- Using the corresponding drill, prepare the canal to the desired length leaving 5 mm of gutta percha. Ideally there should be no gutta percha on the canal walls.
- Take a confirmatory radiograph if unsure of length or completeness of gutta percha removal.
- Once the post space has been prepared, and the post fits passively to the correct length, irrigate the canal with sodium hypochlorite, rinse with water, and dry thoroughly with paper points.
- You are ready to cement the post using either the Rely-X Unicem auto-mix syringe with an elongation tip, or the Rely-X Unicem capsule with an elongation tip. Do not use the ‘clicker’ version of Rely-X Unicem .
- These elongation tips can be tricky to use, so it is important to ensure you hear a click to indicate it is properly attached.
- Initially, express some cement external to the canal and then put the elongation tip in all the way to the bottom of the canal.
- Fill the canal with cement from the apex up
- Place the post firmly into the canal and wipe away excess cement from tooth and coronal part of post. Push post into canal to ensure it is completely seated and in the proper position. Light cure the cement at the top to hold the post in place.
- Light cure the cement alongside the length of the post by holding the tip of the curing light: first at the tip of the post and subsequently at the sides of the post.
- Take the stopper off the post and trim post to size, using a high speed bur (never a use scissors or a wire cutter).
- I like to leave the coronal part of the post as long as possible so that it is bonded to as much of the core as possible.
- Acid etch the tooth and wash off etch after 15 – 30 seconds, then rinse and dry.
- Apply adhesive to tooth and to post. After gently evaporating the adhesive solvent, light cure the adhesive.
- Build up the core with a resin such as Filtek Supreme. The shade used depends on esthetic requirements and also on the convenience of the operator.
- Light cure the resin core.
- Contour the core to the desired shape, using diamonds and a football-shaped bur to contour the lingual surface.
Do you need further information related to this subject? Do you have any comments or suggestions? Email us at oasisdiscussions@cda-adc.ca
Your are invited to comment on this post and provide further insights by posting in the comment box which you will find by clicking on “Leave a reply“ below. You are welcome to remain anonymous and your email address will not be posted.