If you find yourself in a situation where a patient cannot be without their partial denture, but need to adapt the clasp and rest to the new crown you will be fabricating. There actually is a way for the lab to adapt the restoration to the clasp and rest without having the actual partial denture on hand.
How It’s Done
Here is a technique performed successfully many times for indexing partial denture rests and clasps to the underlying preparation using Ramitec® or any heavy-bodied, highly viscous PVS or Polyether. This procedure is performed in the mouth. The stone models shown in the photos are for demonstration only.
- Pre-polish to a high shine, mirror finish the underside of the clasps and rest being sure to remove all plaque and debris.
- Provide a pre-op study case.
- Prep tooth (Photo A), pack cord, and take an impression.
- (Photo B) Mix a small amount of Ramitec about the size of a piece of chewing gum. Place Ramitec over the preparation covering the entire prep, the margins, and just touching the contacting proximal teeth.
- (Photo C) Seat the partial clasp and rest onto the Ramitec, being certain to get a very clear impression of the cleaned and polished underside of the clasp and rests. (ie. the surfaces contacting the tooth)
- (Photo D) Be careful not to bury the clasps or rests, or incorporate any creases, streaks, voids, or bubbles. Allow Ramitec to set completely before removal.
This index along with the pre-op cast will enable the technician to make an acrylic reproduction of the clasps and rests in relation to the prep and proximal teeth.