Allan Deutsch
 
 
 
 

FIGURE 2: Prepare the initial post hole with Gates Glidden reamers.

FIGURE 4: Use the countersink/root facer to form the final post-hole shape.

FIGURE 6: Shorten the post apically enough to allow for full insertion plus an additional 1 mm.

1. Prepare the initial post hole with Gates Glidden reamers (Figure 2).
2. Size the post hole with the primary reamer of choice.  Note that you can eyeball the choice by placing either a post or a template over an undistorted X-ray.  The minimum requirement for placement is 1 mm of lateral tooth structure at the most apical placement of the post within the root (Figure 3).
3. After you have created the primary post hole, use the countersink/root facer to form the final post-hole shape (Figure 4).  Because the countersink/root facer is not self-limiting, you can drill the dual preparation (preparation for the flange and second tier of the Flexi-Overdenture post) fairly deeply into the root.  Drilling deeply has the major advantage of shortening the lever arm of the attachment to a bare minimum.  The shorter the lever arm, the less the forces of occlusion are magnified.  Having a short lever arm may become particularly important if the abutment root is periodontally compromised.
4. Assuming that the primary reamer went the full length, make a trial seating of the post to its full depth (Figure 5).
5. If the post hole is prepared short of its full length, the post will not completely seat.  To ensure seating of the post’s flange, shorten the post apically enough to allow for full insertion plus an additional 1 mm to make sure that the blunt apical end of the post does not impinge on the tapered end of the post-hole preparation (Figure 6).
6. Before cementing the post, place an assembled EZ-Change keeper and cap insert onto the ball of the attachment (Figure 7).  Place marking paste onto the keeper and place the denture over it.  Remove the denture and see where the marks are impinging the denture (Figure 8).  If the keeper impinges to the point where the denture must be perforated for the keeper’s clearance or the keeper impinges in an aesthetically compromising fashion, you may deepen the preparation into the root with the countersink/root facer to gain an extra millimeter or two. 
7. After you have established clearance, place Flexi-Flow Cement with Titanium into the canal with a lentulo spiral reamer.  Place about three increments of cement with an up-and-down motion; this technique will ensure complete coating of the canal walls.  In addition, coat the shank of the post.  The cement acts as a lubricant, further easing the insertion of the post (Figure 9). 
8. Before cold-curing the keeper into the denture, make sure that the rubber band covering the undercut of the ball attachment is in place.  Place pink acrylic into the denture and seat the denture for about five minutes or until the acrylic sets.
9. Remove the denture and relieve the excess acrylic around the keeper (Figure 10).  You can now safely remove the denture from the undercut of the ball attachment.  With this system you may never need to cold-cure any worn-out attachments again. 
10. Place the denture in the patient’s mouth.  The relationship should be the same as before cold curing the keeper into the denture.
11. If at some point the cap insert wears out, take the two-pronged wrench provided in the kit and place it in the holes inside the cap insert and rotate out the old cap with a counterclockwise motion (Figure 11).  At times the cap insert may wear out in such a way that the internal prong holes wear away.  If this is the case, heat the wrench in a flame until the prongs are red and then insert the wrench anywhere into the nylon cap insert.  Wait several seconds while the melted nylon solidifies around the prongs and again rotate counterclockwise for removal. 
12. To place a cap insert (figure 12) , place the prongs of the wrench into the holes inside the insert, line up the thread of the insert with that of the keeper and rotate in with a clockwise motion.  You will feel a tactile click when the cap is fully inserted. Replacement is complete within about 30 seconds chair time and there is no need for cold curing. 
13. Reseat the denture. It should fit as before without any change in alignment. 

FIGURE 1: The EZ-Change Keeper and Cap Insert.

FIGURE 3: Size the post hole with the primary reamer of choice.

FIGURE 5: Make a trial seating of the post to its full depth.