Screwmentation Implant Case- By Thomas W. Mitchell, DDS, FAGD

Introduction: 

Screwmentation is a popular technique that combines the advantage of cementable implant supported crowns (ease of contact and occlusal adjustment) and screw retained crowns (retrievability) and solves the problem of cement sepsis. This one went ideally so it's a good one to look at. This implant is at #3, and there's nothing distal to 3.

Thomas W. Mitchell, DDS, FAGD
My surgeons all know I want a big fat healing cap to expand that tissue away from the implant. This is a Nobel Active WP 5.5 Implant.
Thomas W. Mitchell, DDS, FAGD
When the implant is submerged during healing we allow at least one month after recovery for the tissue to mature so it looks like this for the impression.
Thomas W. Mitchell, DDS, FAGD
Whenever we can we're doing open tray impressions, and with implants always full arch. I'm using a stock tray. We cut a small hole over the implant.
Thomas W. Mitchell, DDS, FAGD
This is the Procera Custom Ti abutment. These are designed so the screw first engages the abutment and then the implant, so it can't fall out of the abutment while we're trying the abutment in. That saves on my dry cleaning bill...
Thomas W. Mitchell, DDS, FAGD
The final torque will be 35 Ncm's, so for the try in I torque to about 20 Ncm's
Thomas W. Mitchell, DDS, FAGD
Then the adjustments begin. For this one proximal contact was ideal and no adjustment was needed. The occlusion was slightly high so we did adjust that.
Thomas W. Mitchell, DDS, FAGD
Then we take the abutment off, REPLACING THE HEALING CAP SO THE TISSUE DOESN'T COLLAPSE (sorry about shouting but that's really important), and, leaving the screw in the abutment pack Teflon tape into the screw access.
Thomas W. Mitchell, DDS, FAGD
Then cement the crown to the abutment. We use Anchor by Apex Dental Materials. We've tried to use Rely X Luting, but even after waiting for 15-20 minutes it wasn't set up. With Anchor we let it sit for 10 minutes. Setting takes longer because it's out of the mouth so not warm. Lots of cement will extrude thru the screw access and we thin that out with the stick end of a topical swab.
Thomas W. Mitchell, DDS, FAGD
Simply wipe off the excess cement and allow the cement to cure before proceeding. Then torque it onto the implant, check for any final adjustments (none were needed with this one but if the path of insertion doesn't match the angle of the proximal contact you'll have to re-adjust that). Try to re-torque it after a couple of minutes.
Thomas W. Mitchell, DDS, FAGD
Then pack Teflon tape over the screw head (to protect it from drilling damage in the event you have to retrieve the crown).
Thomas W. Mitchell, DDS, FAGD
Then I mask that dark hole with first Interface from Apex Dental Materials, allow it to dwell for 10 secs then dry, 2 coats of Surpass 2 and dry, a thin coat of Surpass 3 and a layer of WO Titan Flowable, all co-cured for 10-20 seconds.
Thomas W. Mitchell, DDS, FAGD
Then complete filling the screw access with Exquisite (as shown) and we're done.

Conclusion: 

This one went really smoothly. This is a "steppy" procedure, but you end up with a retrievable crown that looks as good as a cementable and there's no worry about cement sepsis.

Case by: 

Thomas W. Mitchell, DDS, FAGD