Cement Retention of Implant Crowns: What Are You Doing?

hi i am using improv for my crowns.....i tried using vaseline and teomerory cements but i had some decementations... with improv i dint have any problems....although i had to remove the crown of one implant and it wouldnt budge with improv...i had to section it... i think considering the fact that we need to very rarely remove the crowns improv is good.....its better than having patients coming in every other day to recement...its earns us a bad name....patients really get suspicious...they might have had some junk in their mouth by the way of some old restorations with leaky margins and they dont wanna let go of it at times cause its stayed in there for 20 years....you place this implant crown and the patient comes back with it in a couple of months...dosent reflect good on you... cheers...

I use a very minimal amount of temp bond. In theory, the crown and the abutment should be precision fit, so only a very tiny amount is required. I am always fearful of the temp cement extruding down the side of the gingiva into the implant-gingival complex and causing bone loss around my implant. I have had experience of implant failure on one occasion in the past. I have tried cement vent holes, retraction cord etc.. to prevent this from happening. I find, where the gingiva allows, and aesthetics is not crucial, pre-cementation application of retraction cord a good technique. Place the cord, then cement with temp bond, allow it to set then remove the cord and any excess cement will be removed also. I have on the odd occasion had to use glass ionomer cement in instances where my abutment is not retentive. If using temp bond, I always warn my patients that there is a chance that it may come off. If it does de-cement, it is often an occlusal issue.

Mr., Dr.Anon., using one piece implants it might be not so important. If abutment is placed deep, hemidesmosomal attatchment will get disturbed by cementation (regarding 2-piece.impl.). As periodontal resistance is individualy defined- in implant restauration this is defined completely different. Of utter importance is, as implants can not compensate, they are subject to macro-osteonal new definition by the load induced new macro-trajectories. Take care of the opposing jaw and chewing pattern wich will change. A new equilibrum induces a new "common" chewing patern and reorption and apposition of bone. We usualy implant to restore function ! Read principles of BOI by Dr. Ihde et al.

I have had the opportunity of evaluating 22 years of my own implant prosthetics, so with that in mind, I offer these suggestions. 1. use custom abutments for best retention of the crowns or bridges. 2. Place the margin at tissue level, not below. 3. Use Zirconia abutments in the esthetic zone that are shaded to your crown shade for best esthetics, i.e. no metal discoloration of the gingiva. 4. Use Improv, easy clean up and viscosity allows crown to seat all the way, and the crowns will not come off with custom abutments. 4. Do not worry about retrievability issues, you can always cut the crown off, if you need to, as you would on a natural tooth.

Try cutting a "half a rectangle" on the lingual of your custom abutment and a "half a rectangle" on the lingual of your crown, so that together it looks like a full rectangle (supragingival, on the lingual side) where your flat driver can fit. Then you twist the driver, unseating the crown and seating the abutment at the same time. This is a great technique to retrieve cemented crowns with Temp Bond or similar cements. See the article in Quintessence of Dental Technology by Ingber and Prestipino and two more authors. I believe the year was 2000 or 2001.

pretty much agree with dr Gosch. After 15 years and lots of implants I do probably half cemented and half direct screw. In my experience if the fit is correct and occlusion is ok, temporary cement will do just fine for years and years, especially on multi unit restorations.(you get an even more passive fit). No vaseline for our cementations, no need, if something happens I will cut to retrieve and start from scratch anyway so....

New Jung paper (Randomised Controled trial Aug 09 )showed some interesting aspects with regards Zr and Ti abutments and the suprissing thing is there was moe gingival "Blueing" with the Zirconia.

Peter Wat 26th Nov. 09. I always use perm. cement for single unit. Because temp. cement is unreliable it always pick the most awkward moment to fall out. Gives a very bad impression to the patient. I may consider to use temp. cement on multiple unit if retrieving is deemed necessary.

With single units I always cement permanently and with multiple units I try to plan the case out properly so that if I feel I might need to retrieve it I design it as a screw retention. Otherwise I will permanently cement it it. We are selling an expensive,permanent solution to our patients problems and the last thing we need is this solution coming loose at (according to Murphy's Law) at the most inopportune moment which it most certainly will.

There are many opinions on this, and many well respected authors regard it as personal preference. I believe that if you are cementing a large case and would feel better using a softer cement, it is a personal preference question. I do not like removing my crown and bridge cases once I cement them, and on small cases I treat them as a regular crown and bridge case and cement using hard cement. Even if it does not happen often, it is bad for the patient and yourself too when a crown cemented with softer cement falls off at an inoportune time. For selected large cases I will use temporary implant cement.

I use permanent cement, worse case scenario if you need to retrieve it you can drill through the crown and unscrew the abutment, after that you can treat the case as a screw retained.